A system of practical medicine. By American authors. Vol. 5

by Unknown

THE CHRONIC INFLAMMATORY AND DEGENERATIVE AFFECTIONS OF THE SPINAL CORD.

BY E. C. SPITZKA, M.D.

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The intimate dovetailing of parenchymatous and connective substance in the spinal cord renders the determination of the precise origin of a morbid process often difficult if not impossible. Whatever the mode of origin, the typical termination of inflammatory and degenerative spinal disorders is sclerosis—a condition in which the essential nervous elements suffer diminution or destruction, while the connective substance is either absolutely or relatively in preponderance. The clinical result is nearly the same in all cases, and with few exceptions depends less upon the histological character than on the topographical distribution of the lesion. It is for this reason that we shall follow rather the topographical than the morbid histological principle in classification.

The chronic disorders of the spinal cord here considered have as a common character the slow and progressive displacement of the normal conducting nerve-tubes by a grayish, reddish, or otherwise discolored tissue, which is firmer in texture than normal nerve-substance. Minute examination shows that it is above all the myelin of the nerve-tubes that is wasted or destroyed, while the axis-cylinders may share in this dissolution, or, as in one form of sclerosis, they may persist and even continue in their conducting function. This increased consistency is found to be due to the increase of connective-tissue trabeculæ and of the neuroglia. In some cases this increase is active and absolute, like the increase in certain phases of hepatic cirrhosis; in others it is rather relative and passive, being merely a condensation of the connective framework after the intervening elements have wasted away, just as the texture of a compressed sponge is more compact than that of an expanded one.

Crudely, the affections of the cord characterized by this change may be divided into two great groups—the regular and the irregular. The former are characterized by their limitation to special nerve-tracts. Thus, in primary lateral sclerosis we find a special tract in the posterior part of the lateral columns occupied by the lesion. A number of spinal diseases with well-defined symptoms are due to active morbid processes which similarly follow the normal distribution of the great nerve-tracts of the cord, with the same, almost mathematical, regularity with which the medullary white develops in the fœtal and infantile cord. In another class of cases we find that the same tracts are involved in like manner—not in the way of primary disease, but through the interruption of the physiological continuity of the nerve-tract by some other disease, to which the sclerosis is therefore secondary. These are the so-called secondary degenerations.

The irregular affections of the cord comprise cases in which the sclerotic foci are either disseminated through the cerebro-spinal axis in numerous foci, or diffusely involve a greater or lesser length and thickness of the medullary cylinder, or, finally, extend in the transverse plane completely or nearly so across the section area of the cord at a definite level.

As the symptoms of the regular affections of the cord are by far the most readily recognizable, and a preliminary knowledge of them will facilitate the better understanding of the irregular forms, we shall consider the former first. They may be subdivided into two groups. The largest, longest known, and best studied consists of acquired, the other, containing less numerous cases and varieties, and rendered familiar to the profession only within the last decade, comprises the spinal disorders due to defective development of the cerebro-spinal and spinal-fibro systems.

Tabes Dorsalis.

SYNONYMS.—Locomotor ataxia and ataxy, Posterior spinal sclerosis; Graue degeneration der Hinterstränge (Leyden), Rückenmarksdarre (popular), Rückenmarksschwindsucht; Tabes dorsualis (Romberg); Ataxie locomotrice progressive (Duchenne).

HISTORY.—Undoubtedly, this disease must have been observed by the ancient masters of medicine, but their descriptions group together so many symptoms of other organic as well as functional diseases of the cord that it is impossible to obtain a clear idea as to what special form they had in view when they spoke of tabes dorsualis. This term was adopted by the German writers of the last and the earlier part of this century as designating all wasting affections of the cord; and it was not till Romberg in 1853 and Duchenne in 1858 differentiated the characteristic clinical signs, and Cruveilhier and Todd (1847) determined the distribution of the lesion in the posterior columns, that the medical profession began to recognize the distinctness of this the most common form of organic spinal ailment.

At this time, when tabes dorsalis became recognized as a clinical entity depending on sclerotic degeneration of the posterior segment of the cord, the inco-ordination or ataxia manifested in the peculiar gait of the patient was regarded as the most characteristic, essential, and constant symptom of the disease. It was regarded as an axiom in physiology that the posterior segment of the cord was subservient to centripetal and sensory conduction, and nothing appeared to follow more naturally than the conclusion that the patient exhibited inco-ordination because, his sensory conduction being interrupted or destroyed, he had lost the necessary gauge for judging of the required extent and force of a given movement. Since then both spinal physiology and pathology have undergone a profound revolution. So far are we to-day from regarding anterior and motor or posterior and sensory as convertible terms that we locate the most important centrifugal tract of the cord behind the plane which divides it into anterior and posterior halves, while the most recently differentiated centripetal tract is represented by Gowers as lying in front of it. It has been determined, through Türck, Bouchard, and Flechsig and his pupils, that the posterior white columns of the cord contain several systems of fibres, whose functions—where determinable—are of an exceedingly complex nature. The elaborate investigations of Charcot, Schultze, and Strümpell, made during the past decade, have shown that the distribution of the diseased field in the posterior segment is not uniform, but is most intense in special areas. These were found to be affected with a remarkable constancy and regularity. Almost coeval with this discovery came the recognition of symptoms found in the earliest phases of the disorder by Westphal, which, attributable as they were found to be to the involvement of the special reflex mechanisms of the cord, enable us to demonstrate the existence and extent of the disease at periods which previously were not within the ken of the clinician. The reproach which Leyden was justified in making, that most tabic patients pass through the pre-ataxic phase of their disorder under the diagnosis of rheumatism or some similar affection, can now no longer be made. Our ability to recognize the advent of this disease has reached such a degree of refinement that the question arises whether we are always justified in alarming a patient who has a prospect of remaining free from invalidating complications for many years with the announcement of a disease which, above all other spinal affections, is looked upon with dread as equally hopeless, insidious, and distressing.

CLINICAL HISTORY.—The development of tabes dorsalis is typically slow and its precise commencement usually not determinable. In some cases this or that one of the characteristic symptoms of the disease preponderates from the beginning, and continues throughout the illness as a prominent feature; in others distinct stages can be recognized, each marked by one or several symptoms which were absent or slight in the other stages. In some cases the progress of the affection is marked by episodes which are absent or rare in other cases. As a rule, however, it may be stated that tabes is a progressive affection, marked by pronounced temporary changes for better or worse, which are often developed with astonishing rapidity, and subside as quickly, terminating fatally unless its progress be arrested by treatment or interrupted by some other fatal affection. The latter is by far the more frequent termination in the well-to-do class of sufferers.

For purposes of convenience we may consider the symptoms of the earlier period of the illness as pre-ataxic, and those of the later as the ataxic. It is to be remembered, however, that in the strictest sense of the term there is usually some disturbance of co-ordination even in the early period, while the symptoms of the pre-ataxic period continue over the ataxic period, and may even become aggravated with it. Often the patient does not himself suspect a spinal, or indeed any nervous, disorder, and consults the physician either on account of rheumatic pains, double sciatic neuralgia, bladder disturbance, diminished sexual power, amaurosis, diplopia, or even gastric symptoms, which on closer examination are revealed to be evidences of tabes. The determination of the initial symptoms is retrospective as a rule.

Of the subjective signs, one of the commonest, if indeed it be ever entirely absent, is a tired feeling, particularly noted in the knees and ankles. This sensation is compared to ordinary muscle-tire, but is provoked by slight exertion, and not as easily remedied by rest. Often a numb feeling is associated with it, although no objective diminution of cutaneous sensation be determinable. This combined feeling of tire and numbness, described as a going-to-sleep feeling in the ankle, has indeed been claimed by one observer¹ to be pathognomonic of early tabes. Next in frequency, and almost as universal, are peculiar pains: these are manifold in character and distribution, but so distinctive as to alone suggest the existence of the disease from the manner in which the patient describes them. One variety, the lightning-like, is compared to a sudden twinge of great intensity shooting through the limb. The sciatic and anterior crural branches are the lines usually followed by this pain, but there are cases where perineal and abdominal regions are affected. Often the pain is so severe that the patient cries out or the limb is violently contracted under its influence. It differs from rheumatic pain in the fact that it is distinctly paroxysmal and that the intermissions are complete; that it is not greatly aggravated by motion nor relieved by rest, while the rheumatic pain is; that tabic pain is usually relieved, and rheumatic pain aggravated, by pressure, while hyperæsthesia is present with the former, and either absent or barely indicated with the latter. The lightning-like pains are sometimes combined with another form, which is even more distinctive in character. This form does not affect the distribution of special nerves, but is found limited to a small area which the patient is able to localize definitely: it may not exceed a centimeter or two in diameter, and within this area the pain is excruciating. It is either of a burning character or compared to the firm pressure of a vise or heavy weight, or to the tearing, boring, and jumping of a violent toothache.

¹ Canfield, Lancet, 1885, vol. ii. p. 110.

While some patients escape these pains almost entirely,² others are tormented with them at intervals for years, their intensity usually diminishing when the ataxic period is reached. There is little question among those who have watched patients in this condition that their pains are probably the most agonizing which the human frame is ever compelled to endure. That some of the greatest sufferers survive their martyrdom appears almost miraculous to themselves. Thus, in one case the patient, who had experienced initial symptoms for a year, woke up at night with a fulminating pain in the heels which recurred with the intensity of a hot spear-thrust and the rapidity of a flash every seven minutes; then it jumped to other spots, none of which seemed larger than a pin's head, till the patient, driven to the verge of despair and utterly beside himself with agony, was in one continued convulsion of pain, and repeatedly—against his conviction—felt for the heated needles that were piercing him. In another case the patient, with the pathetic picturesqueness of invalid misery, compared his fulminating pains to strokes of lightning, “but not,” he added, “as they used to appear, like lightning out of a clear sky, but with the background of a general electrical storm flashing and playing through the limbs.”

² I have at present under observation two intelligent patients (one of whom had been hypochondriacally observant of himself for years) who experienced not a single pain, as far as they could remember, and who have developed none while under observation. Seguin mentioned a case at a meeting of the Neurological Society with a record of but a single paroxysm of the fulgurating variety. Bramwell (Brit. Med. Journ., Jan. 2, 1886) relates another in which the pains were entirely absent.

Either while the pains are first noticed or somewhat later other signs of disturbed sensation are noted. Certain parts of the extremities feel numb or are the site of perverted feelings. The soles of the feet, the extremities of the toes, the region about the knee-pan, and the peroneal distribution, and, more rarely, the perineum and gluteal region, are the localities usually affected.³ In a considerable percentage of cases the numbness and tingling are noted in the little finger and the ulnar side of the ring finger; that is, in the digital distribution of the ulnar nerve. The early appearance of this symptom indicates an early involvement of the cord at a high level. Some parallelism is usually observable between the distribution of the lightning-like pains when present and the anæsthesia and paræsthesia if they follow them. With these signs there is almost invariably found a form of illusive sensation known as the belt sensation. The patient feels as if a tight band were drawn around his body or as if a pressure were exerted on it at a definite point. This sensation is found in various situations, according as the level of the diseased part of the cord be a low or high one. Thus, when the lower limbs are exclusively affected or nearly so the belt will be in the hypogastric or umbilical region; if the upper limbs be much involved, in the thoracic region; and if occipital pain, anæsthesia of the trigeminus, and laryngeal crises are present, it may even be in the neck. Correspondingly, it is found in the history of one and the same patient: if there be a marked ascent—that is, a successive involvement of higher levels in the cord—the belt will move up with the progressing disease. This occurrence, however, is less frequently witnessed than described. In the majority of cases of tabes disturbances of the bladder function occur very early in the disease. Hammond indeed claims that in the shape of incontinence it may be the only prodromal symptom for a long period.⁴

³ In the exceptional cases where the initial sensory disturbance is marked in the perineal and scrotal region I have found that the antecedent fulminating pains had been attributed to the penis, rectum, and anal region; and in one case the subjective sense of a large body being forcibly pressed through the rectum was a marked early sign.

⁴ New England Medical Monthly, 1883.

I have under observation a patient who has been compelled to use the catheter daily for years, who has gradual disappearance of the knee-jerk and reflex iridoplegia, but who has presented no other evidence of tabes during the year and a half he has been watched. Among the exact signs of tabes, reflex iridoplegia and abolition of the knee-jerk are probably the earliest to appear. It may be assumed with safety that in ninety-nine out of a hundred cases both the inability of the pupil to respond to light and the absence of the knee-jerk will be found long before ataxia is developed. Cases are recorded where no other positive signs were found, and no other signs of the disease developed for a number of years,⁵ and others where disappearance of the knee-jerk was the very first indication.

⁵ Westphal, also Tuczek, Archiv für Psychiatrie, xiii. p. 144.

The opinion of observers as to the frequency of double vision as an early symptom of tabes is far from being unanimous. The majority of writers speak of it as rare, but it is probable that this usually transient symptom is forgotten by the patient, or because of its apparent triviality escapes notice. The patient while looking at an object sees a double image of the latter. This may last for a few seconds, minutes, or hours, and rarely for a day or week.⁶ A distinct history of this symptom was given by 58 out of 81 patients in whom I recorded the oculo-motor signs. By far the most important of the exact prodromal signs of tabes are two symptoms—one involving a special faculty of co-ordination, the other the reflex movements of the pupil. One or both of these must be present to justify the diagnosis of incipient tabes.⁷ The disturbance of co-ordination consists in an inability of the patient to stand steadily when his eyes are closed. The majority of healthy persons when tested in this way may show a little swaying in the beginning, but eventually they stand as steadily as they do with open eyes, and there is no subjective feeling of uncertainty as to falling. But the tabic patient exhibits oscillations, and makes efforts to overcome them which, instead of neutralizing, usually aggravate them and betray the great disturbance of his equilibrium. It is not as if he swayed merely because he is uncertain of his upright position, but as if some perverted force were active in throwing him out of it. It is found to be a pronounced feature even in cases where the patient with open eyes is able to walk nearly as well as normal persons, and experiences no trouble in performing intricate evolutions, such as dancing, walking a line, or even walking in the dark—faculties which the patient is destined to lose as his disease progresses.⁸

⁶ It has been asserted that the severer and more persistent diplopias are found with tabes dependent on syphilis.

⁷ Not even the absence of the knee-jerk ranks as high as these two signs. Aside from the fact that this is a negative symptom, it is not even a constant feature in advanced tabes.

⁸ It does not seem as if the disturbance of static equilibrium were due merely to the removal of the guide afforded by the eyes, for it is noted not alone in patients who are able to carry out the average amount of locomotion in the dark, but also in those who have complete amaurosis. Leyden (loc. cit., p. 334) and Westphal (Archiv für Psychiatrie, xv. p. 733) describe such cases. The act of shutting the eyes alone, whether through a psychical or some occult automatic influence, seems to be the main factor.

In most cases of early tabes it is found that the pupil does not respond to light; it may be contracted or dilated, but it does not become wider in the dark nor narrower under the influence of light. At the same time, it does contract under the influence of the accommodative as well as the converging efforts controlled by the third pair, and in these respects acts like the normal pupil. It is paralyzed only in one sense—namely, in regard to the reflex to light; just as the muscles which extend the leg upon the thigh may be as powerful as in health, but fail to contract in response to the reflex stimulus applied when the ligamentum patellæ is struck. For this reason it is termed reflex iridoplegia.⁹ It is, when once established, the most permanent and unvarying evidence of the disease, and is of great differential diagnostic value, because it is found in comparatively few other conditions.

⁹ It is also known as the Argyll-Robertson pupil. Most of the important symptoms of tabes are known by the names of their discoverers and interpreters. Thus, the swaying with the eyes closed is the Romberg or Brach-Romberg symptom; the absence of the knee-phenomenon, Westphal's or the Westphal-Erb symptom; and the arthropathies are collectively spoken of as Charcot's joint disease.

In a number of cases ptosis of one or both eyelids is noted at an early stage of the disease. It is usually temporary, and coincides as to time with the diplopia, if present.

Patients presenting some or all of the subjective and objective manifestations of tabes mentioned may continue in a condition of otherwise comparative health, enabling them to attend to their vocation for from one to twenty years, and it is not improbable that the pre-ataxic period may extend over nearly a lifetime. In a less fortunate minority of cases some of the most distressing evidences usually marking the last stages of the disease are found developed at the onset. Thus, cases are known where optic nerve-atrophy preceded the true tabic period by ten or more years; others in which trophic disturbances, manifested in spontaneous fractures of bones¹⁰ or violent gastric crises, or even mental disturbance, inaugurated tabes dorsalis, instead of closing or accompanying the last chapter of its history, which is the rule.

¹⁰ Berger, Deutsche medizinische Wochenschrift, 1885, 1 and 2.

The disturbance of co-ordination above spoken of as manifested in the inability of the patient to stand well with his eyes closed is the first step in the development of the characteristic ataxia which marks the full-blown affection. The patient finds that he tires more and more on slight exertion—not because his muscles are weak, but because he has to make more voluntary effort than a person in health. He finds that he stumbles easily—is unable to ascend and descend at the curbstone or to walk over an irregular surface with ease. Going down stairs is peculiarly irksome. “I would rather,” aptly said one patient, “troubled as I am in walking, go a mile in the street than walk up three flights of stairs; but I would rather go up six flights of stairs than walk down one.” Soon the patient notices that walking in the dark becomes more a feat of relative skill than the easy, almost automatic, act it was in health. His vocation, if it was one involving the use of the feet, becomes irksome, difficult, and finally impossible, and in a number of cases the upper extremities are also involved.¹¹ Delicate motions, such as those required in needlework, in writing, and by watchmakers, musicians, opticians, and lapidaries, are clumsily performed; even coarser movements, such as buttoning the clothes and carrying a glass filled with water to the mouth, are performed in an uncertain and clumsy manner. Meanwhile, the disturbance of motion in the lower limbs progresses. Difficult as it formerly was for the patient to stand on one foot or with both feet together while the eyes were closed, he is now unable to do either with the eyes open. He straddles in his walk, or, in order to overcome the element of uncertainty involved in moving the knee-joint, keeps this joint fixed and walks with short, stiff steps. If ordered to halt suddenly while thus walking, the patient sways violently, and makes movements with his hands or arms to recover his balance, in some cases staggering and even falling down. He shows a similar unsteadiness when told to rise suddenly from a chair or to mount one, and it becomes impossible for him to walk backward. Later on, it will be found that his feet interfere in walking. He has lost the power of gauging the extent and power of his motions to such a degree that he may actually trip himself up. To neutralize in some way this element of uncertainty of his steps, the patient is compelled to exaggerate all his ambulatory movements, and there results that peculiar gait which was the first symptom directing attention to the disease to which it is due. The feet are thrown outward, and violently strike the ground; the heel touches the latter first, and the patient appears as if he were punishing the ground and stamping along instead of walking. The reason for his adopting these tactics are twofold. In the first place, he has a subjective sense of walking in a yielding substance, as if on a feather bed, air-bladders, cushions, or innumerable layers of carpet, and he therefore makes efforts to touch firm bottom. In the second place, his motor inco-ordination, in so far as it is not the result of anæsthesias, is greatest in those segments of his limbs which are farthest removed from the trunk, and which, enjoying the greatest freedom of combined motion, are also most readily disturbed. His uncertainty is therefore greater in the toes than in the ankle, greater in the ankle than in the knee, and greater in the knee than in the thigh: he prefers to touch the ground with the heel to touching it with the toes, and to move his limb in the hip than in the knee-joint. As the patient advances in life even this limited and clumsy form of locomotion becomes impossible: he takes to his bed, and it is found that he loses all sense of the position of his lower and occasionally of his upper limbs. He is unable to tell which limb overlies the other when his leg is crossed—unable to bring one limb in parallel position with another without the aid of his eyes. If told to touch one knee or ankle with the toes of the other side, his limb oscillates around uncertainly, and makes repeated unskilful dashes at the wrong point, and ultimately all but the very coarsest muscular co-ordination appears to be lost, even when the supplementary aid of the eyes is invoked.

¹¹ Cases in which the upper extremities are intensely involved in the beginning are uncommon, and those in which they are more intensely involved than the lower, or exclusively involved, may be regarded as pathological curiosities.

Together with this gradual impairment and abolition of co-ordination, which has given the name of locomotor ataxia to the disease, but not always in that strict parallelism with it on which Leyden¹² based his theory of inco-ordination, the sensory functions proper become perverted and impaired. Usually the determinable anæsthesias are preceded by subjectively perverted sensations, such as the numbness already referred to, or even by hyperæsthesia. Usually, all categories of cutaneous sensation, whether special or pathic, are impaired in advanced tabes; the points of the æsthesiometer are not readily differentiated; the patient is unable to correctly designate the locality which is touched or pinched; the pain-sense is occasionally so much blunted that a needle may be run through the calf of the leg without producing pain, and in some cases without being appreciated in any form. Even if the pain-sense be preserved, it will be found that its appreciation by the patient is delayed as to time. Not infrequently bizarre misinterpretations are made of the impressions acting on the skin. One of these, the feeling as if the patient were standing on carpet, cushions, or furs, whereas he may be standing on stone flagging, has already been mentioned as a factor in the disturbed locomotion of the patient. In the later period, numerous perversions of this kind are noted: to one of these, already mentioned by Leyden, Obersteiner has called renewed attention. It consists in a confusion of sides; the patient when pricked or touched on one foot or leg correctly indicates the spot touched, but attributes it to the wrong side.¹³

¹² Klinik der Rückenmarkskrankheiten, Band ii.

¹³ Allochiria is the term applied by Obersteiner. Hammond has offered an explanation, which, as it is based on the assumption of altogether hypothetical nerve-tracts, and not in any sense accords with positively established facts, is more properly a subject for consideration in a theoretical treatise.

While it may be affirmed, as a general proposition, that the tendency of the tabic process is to abolish sensation below the level of the disease, there are noteworthy exceptions, not only in individual cases, but with regard to certain kinds of sensation; nor do the different kinds of sensation always suffer together. Thus, the pain-sense may be blunted and the contact-sense preserved, or, more commonly, the latter blunted and the former exaggerated, so that the unfortunate patient, in addition to being debarred of the useful varieties of sensation, those of pressure and space, has the painful ones exaggerated, as a hyperalgesia. According to Donath,¹⁴ the temperature-sense is usually blunted in tabes, and a greater degree of heat or cold can be borne without discomfort than in health; but in about two-sevenths of the cases studied there was increased sensitiveness to heat, and in one-seventh to cold. One of the commonest manifestations is delayed conduction. This interesting phenomenon has been especially observed in that phase of the disease where tactile perception is beginning to be blunted. If the patient be pricked with a pin, he feels the contact of the latter at the proper moment as a tactile perception, and then after a distinct interval, varying from one to four seconds, his limb is suddenly drawn up and his face contorted under the influence of an exaggerated pain. This fact furnishes one of the chief grounds for the assumption that there are distinct channels for the transmission of pain and tactile perception in the cord, and that they may be involved separately or with different intensity in the disease under consideration. In some advanced cases it is found that not only the transmission of pain-appreciation is delayed, but that there are after-sensations recurring at nearly regular intervals of several seconds, and accurately imitating the first pain-impression.

¹⁴ Archiv für Psychiatrie, xv. p. 707.

To what extent the muscular sense is affected in tabes at various stages of the disorder is somewhat in doubt. Strümpell¹⁵ by implication, and other writers directly, attribute the inco-ordination observed on closing the eyes to the loss of the muscular sense. As this symptom is also observed in patients who when they lie on their backs are able to execute intricate movements notwithstanding the exclusion of the visual sense, and as their uncertainty in an early stage is not always with regard to the position of their limbs nor the innervation of individual or grouped muscles, it seems inadmissible to refer the Romberg symptom¹⁶ to the loss of muscular sense alone.

¹⁵ Lehrbuch der Speciellen Pathologie und Therapie, p. 193, vol. ii.

¹⁶ It should be designated as static ataxia, in distinction from locomotor or motor ataxia, which is manifested in unskilled movements.

The important part played by eye symptoms in the early stages of tabes has been already referred to. Reflex iridoplegia is one of these early and persisting features; it is sometimes complicated with mydriasis, and occasionally with paralysis of accommodation of one eye. In the majority of my cases there was spinal myosis, often of maximum intensity; in a large number there was in addition irregularity of the outline of the pupil; and where there was mydriasis I found it to be quite symmetrical, in this respect differing from the experience of Müller¹⁷ and Schmeichler.¹⁸

¹⁷ Centralblatt für die Gesammte Therapie.

¹⁸ Loc. cit.

Atrophy of the optic nerve is a common and sometimes, as stated, the initial symptom of tabes. It is rarely found in its incipient phase in advanced stages. The patient who escapes involvement of the optic nerve in the pre-ataxic stage is very apt to escape it altogether. It is more frequently found either to precede the pre-ataxic period by months and even years, or to develop during this period, leading to complete atrophy in the ataxic period, and sometimes before. Erb calculates that 12 per cent. of tabic patients have optic-nerve atrophy; he probably includes only such cases in which the atrophy was marked or led to amblyopia. Including the lesser degrees of atrophy, it is found in a larger number of patients. Schmeichler claims as high as 40 per cent.¹⁹ If we regard those cases in which there is noted progressing limitation of the color-field of the retina as beginning optic-nerve atrophy, the majority of tabic patients may be said to have some grade of this disorder. The ophthalmoscopic changes are quite distinctive: at first there is noted a discoloration of the papilla and apparent diminution of the number of arterial vessels; the veins then become dilated; and finally the papilla becomes atrophied, the vessels usually undergoing a narrowing after their previous dilatation. In the first stages of this process visual power is not gravely impaired, but as soon as shrinkage has set in visual power sinks rapidly to a minimum, decreasing till only quantitative light-perception remains. This limited function usually remains throughout, but in a few cases complete amaurosis ensues. As the field of vision becomes diminished, the concentric extinction of quantitative perception is preceded by concentric extinction of color-perception, the color-field for green being the first to suffer; red follows, and blue remains last.

¹⁹ Archives of Ophthalmology and Otology, 1883.

In a large number of cases the only symptoms attributable to a disturbance of the cerebral functions are those connected with the motor relations of the eyeball and pupil, and the function and appearance of the optic nerve. The special senses other than those of sight and touch are rarely affected. Sometimes there is obstinate tinnitus, exceptionaly followed by deafness, attributed to atrophy of the auditory nerve. The development of symptoms resembling those named after Ménière is not referable with certainty to a disturbance of the same nerve.

The sexual functions become involved in all cases of tabes sooner or later. In the majority of cases there is a slow, gradual extinction of virile power; in a large minority this extinction is preceded by irritative phenomena on the part of the genital apparatus. Some patients display increased sexual desire and corresponding performing powers, but mostly they suffer from erections of long duration which may be painful, and loss of the normal sensations attending the sexual orgasm. There is no constant relationship between the intensity of the general affection and the diminution of sexual power. It is retained to a limited degree by patients who are barely able to walk, and it may be entirely destroyed in those who have but entered the initial period.

The bladder disturbance,²⁰ which in some forms is usually found among the initial symptoms, is always a marked feature in the ataxic period. Usually, there is a frequent desire for micturition, with more or less after-dribbling; sometimes there is retention, alternating with involuntary discharge; complete incontinence may close the scene through the channel of an ensuing cystitis and pyelitis. With the incontinence of urine there is usually found obstinate constipation, which may be varied by occasional spells of incontinence of feces. The crises of tabes often complicate these visceral symptoms.

²⁰ Contrary to what might be anticipated from the topographical nearness of the vesical and genital centres in the cord, the disturbances of bladder function and virile power do not go hand in hand.

The reflex disturbances are among the most continuous evidences of the disease. Of two of these, the disappearance of the patellar jerk or knee-phenomenon and the inability of the pupil to react to light, we have already spoken when discussing the initial period. Practically, it may be claimed that both are always found in typical tabes. It has been claimed that the patellar jerk may be exaggerated, or even that its disappearance is preceded by exaggeration. As this disappearance usually occurs extremely early in the pre-ataxic period, it is difficult to follow the deductions of those who claim to have watched an alleged earlier phase of exaggeration. It is more than probable that cases of combined sclerosis, in which the lateral columns were affected together with or earlier than the anterior, have been mistaken for typical tabes. Here, it is true, the jerk is first exaggerated through the disease of the lateral column, and later abolished as the lesion in the posterior reflex arch progresses and becomes absolute.

Other tendinous reflexes²¹ suffer with the knee-jerk in the peripheries corresponding to and below the involved level of the cord. The cutaneous reflexes are usually abolished, but may be retained in advanced stages of the disease. The same is true of the cremaster reflex.

²¹ Whether the tendon phenomena are true reflexes or not is a question still agitating physiologists. Opinion inclines in favor of their reflex nature, and, pathologically considered, it is difficult to regard them in any other light.

Opinion is divided as to the electrical reactions in tabes dorsalis. That qualitative changes never occur in uncomplicated cases all authorities are agreed, but while Strümpell and other modern writers claim there is no change of any kind, a number of careful investigators have found an increased irritability in the initial period, particularly marked in the peroneal group of muscles (Erb). In my own experience this is frequently the case, where lightning-like pains are the only subjectively distressing symptoms complained of.

While the symptoms thus far considered as marking the origin and progress of tabes dorsalis are more or less constant, and although some of them show remarkable remissions and exacerbations, yet may in their entity be regarded as a continuous condition slowly and surely increasing in severity, there are others which constitute episodes of the disease, appearing only to disappear after a brief duration varying from a few hours to a few days: they have been termed the crises of tabes dorsalis. These crises consist in disturbances of the functions of one or several viscera, and are undoubtedly due to an error in innervation provoked by the progressing affection of the spinal marrow and oblongata. The most frequent and important are the gastric crises. In the midst of apparent somatic health, without any assignable cause, the patient is seized with a terrible distress in the epigastric region, accompanied by pain which may rival in severity the fulgurating pains of another phase of the disease, and by uncontrollable vomiting. Usually, these symptoms are accompanied by disturbances of some other of the organs under the influence of the pneumogastric and sympathetic nerves. The heart is agitated by violent palpitations, a cold sweat breaks out, and a vertigo may accompany it, which, but for the fact that it is not relieved by the vomiting and from its other associations, might mislead the physician into regarding it as a reflex symptom. In other cases the symptoms of disturbed cardiac innervation or those of respiration are in the foreground, constituting respectively the cardiac and bronchial crises. Laryngeal crises are marked by a tickling and strangling sensation in the throat, and in their severer form, which is associated with spasm of the glottis, a crowing cough is added.²² Enteric crises, which sometimes coexist with gastric crises, at others follow them, and occasionally occur independently, consist in sudden diarrhœal movements, with or without pain, and may continue for several days. Renal or nephritic crises are described²³ as resembling an attack of renal colic. The sudden disturbances of bladder function have been described as vesical crises, and recent French observers have observed so-called crises clitoridiennes in female tabic patients which were characterized by voluptuous sensations. All of these symptoms have these in common: that they last but a short time, that their disappearance is as rapid as their advent, and that they depend for their distribution on the attitude of the disease in the cord. The vesical crises are more apt to occur early than late in the disease and where the belt sensation is in the hypogastric region. The gastric and enteric crises are usually found when the belt is in the epigastric level, and the bronchial, cardiac, and laryngeal crises when it is in the thorax and neck. Some connection has been observed between the occurrence of the lightning-like pains and these crises. Thus, a sudden cessation of the former is sometimes the forerunner of the latter. It is also found that one variety of these crises disappears to give way to another: this is particularly noticed with the bronchial crises, which often cease suddenly, to be followed by vomiting.

²² Krause, in a paper read before the Society of Neurologists at Berlin (Neurologisches Centralblatt, 1885, p. 543), found either laryngeal crises or other laryngeal symptoms, such as demonstrable ataxia of movement of the vocal cords, in 13 out of 38 cases. This proportion would be far too high for tabes in general; his cases were probably advanced ones. He established the interesting fact that the laryngeal crisis may sometimes be provoked by pressure with a probe on the superior laryngeal nerve at its laryngeal entry-point. Jastrowitz claims to have determined the existence of actual paralysis of the vocal cords with the crises, but Krause concludes from the experimental inductibility of the crisis that it cannot be due to a posticus paralysis. In a discussion on the subject Remak affirms that a unilateral paralysis of the crico-arytenoideus posticus may be an early or the earliest symptom of tabes. It seems, however, that in all cases where he determined such paralysis there had been disturbances of function of other cranial nerves in unusual severity at about the same time.

²³ They must be extremely rare: they have not occurred in a single one of my 81 private cases, nor do I recall one in clinic or dispensary experience.

There is some analogy between the exceptionally-occurring mental disturbance of tabic patients and the crises. Like them, it resembles a disturbance of innervation, in this instance the centres regulating the cerebral circulation appearing to be at fault. It also seems as if in cases of this character the direction of the mental disturbance were determined in some sense by the emotional relations of the oblongata, for the insane outbreak usually consists in a brief but extreme outburst either of a depressed and melancholiac or an expansive maniacal or delirious outburst. It is a very rare occurrence, and usually limited to the latest stages. Much more common is the development of paretic dementia, but this is to be regarded rather as a complication than an integral feature of tabes. Most tabic patients retain their mental equilibrium to the last moment; some develop truly heroic resignation to their terrible sufferings and gloomy prospects; and a few, becoming irritable, petulant, and abnormally selfish, show the effect of invalidism manifested equally with other chronic diseases.

In addition to the visceral crises there are other disturbances of innervation of a nutritive or trophic character which are characteristic of tabes. There is scarcely one of the eruptions or other changes which are attributable to central nervous disease which may not occur at some one or other period of this disease. Thus, herpetic eruptions may occur independently or in conjunction with lancinating pains, in one case even corresponding to the area of the belt sensation. Discoloration of the skin or hair, the latter turning gray or white in circular²⁴ or in irregular patches, spontaneous falling of the nails, spontaneous hemorrhages in the matrix of the nail, ichthyosis,²⁵ purpura, diffuse œdemas, localized perspiration sometimes associated with sudamina and accompanied by ecchymoses, muscular atrophies, bullæ, and pemphigus-like eruptions, have been noted by various observers. As yet, they are to be regarded rather as clinical curiosities than as constant features, as diagnostic criteria, or as presenting special indications for treatment. The trophic disturbances affecting the bones and joints and a peculiar ulcerative process known as the perforating ulcer of the foot are better studied, and, ranking among the most formidable and striking manifestations of tabes, merit special consideration. The tabic joint affection, first described by Charcot as a trophic manifestation of tabes, is usually located in the hip or knee, but almost any joint, including the temporo-maxillary articulation, may be its seat. The earlier or lighter forms consist in serous exudations with or without active local manifestations resembling those of synovitis; but the commoner and graver form consists in actual deformity of the articular surfaces, such as enlargement or atrophy, sometimes supplemented by the formation of osteophytes. In addition, spontaneous dislocations occur in a manner which is often quite surprising.²⁶ As a type of such an occurrence the following may serve: A tabic patient presented a synovial swelling of the left knee of truly enormous dimensions; as soon as this became reduced a distinct crepitus was elicited, and both the femoral and tibial articular surfaces found enlarged. The whole process occupied only a few days; the lateral ligaments were then found so relaxed that the leg could be freely moved in every direction.

²⁴ Rossolymmo, Archiv für Psychiatrie, xv. p. 727. I have never observed this symptom as beautifully developed as in a case of spinal irritation, in which the possibility of the existence of any organic disease could be positively excluded. Bulkley has observed albinism.

²⁵ In three cases by Ballet et Dutil, Progrès médicale, May 19, 1882.

²⁶ Boyer (Revue de Médecine, 1884, p. 487) records a case where the hip became luxated spontaneously as an early symptom.

The connection between the morbid process in the spinal cord and these remarkable arthropathies is as yet unexplained; and as Charcot's original proposition, that they can be always referred to lesions in the anterior horns of the gray matter, has not been sustained, some of the German clinicians, notably Strümpell, are inclined to attribute them, in part at least, to ordinary results and accidents due to the anæsthesia and its disturbing effect on voluntary and automatic joint protection. A controversy arose which was participated in by the Clinical Society of London,²⁷ and evoked opinions from nearly all the eminent neurologists of Europe. The result of this thorough discussion has been to establish the joint affection as a true tabic symptom due to the same morbid process which underlies the less enigmatical symptoms of the disease. One of the best reasons for regarding these joint lesions as of trophic origin is the fact that they are associated with textural bone-changes by which they become either unduly soft or brittle, and therefore exposed to apparently spontaneous fracture. Cases of fracture of almost every long and some of the short bones are recorded, among the most remarkable being one by Dutil,²⁸ where fracture of the radius occurred without adequate cause in the initial period of tabes; and one by Krönig,²⁹ in which the patient, who had been tabic for eight years, broke a lumbar vertebra while catching himself in the act of falling down stairs.

²⁷ The question was formally raised by Morrant Baker at the December meeting in 1884, and the discussion participated in by Charcot himself. Among the opponents of Charcot's theory were Jonathan Hutchinson and Moxon, the latter of whom administered a sound and well-merited criticism regarding some of the premature, if not sensational, announcements of the distinguished French neurologist. He compared the joint lesions of tabes to decubitus: just as the latter can be avoided by a proper protection of the exposed parts, so the former would not occur if the joints could be kept in a, surgically speaking, normal state. Moxon seems to have forgotten, in suggesting this comparison, that there is a form of decubitus which will occur independently of the greatest care and in spite of every measure taken to arrest it, and which can be attributed only to an obscure but active perversion of nervous nutritive control. Barwell, Paget, Herbert Page, Broadbent, and McNamara agreed that the joint lesions are not of surgical or rheumatic origin, but essentially signs of the nervous affection. Although Barwell's claim, that the rheumatic and tabic joint diseases are essentially different, because the former is hyperplastic and the latter is atrophic, is not borne out by all cases of tabic joint disease, some of which are certainly hyperplastic, yet the other reasons advanced for regarding these affections as distinct, and considering the joint affection of Charcot as a trophic disorder, far outweighed those advanced by the opponents of this view. In fact, the only ground the latter had to stand on was the fact that Charcot's asserted anatomical foundation was found to be chimerical.

²⁸ Gazette médicale de Paris, 1885, No. 25.

²⁹ Zeitschrift für klinische Medizin, 1884, vii., Suppl. H.

Another reason for considering the arthropathies as of central origin is their chronological association with other signs whose trophic origin cannot be disputed, such as unilateral sweats and œdemas and visceral crises. They are also found to correspond in many cases to the lancinating pains both in location and time.

The feet of an advanced tabic patient usually appear deformed; the extremities of the bones, particularly at the metacarpo-phalangeal articulation, are thickened, and the axis of the foot as a whole is bent. It is a question how far this deformity may be due to persistent faulty innervation of the muscles going to the foot and to ensuing mechanical influences. A most pronounced deformity found in a few cases has been designated by Féré as the tabic foot.³⁰ It consists in the thickening of the tissues on the inner side of the foot, obliterating its arch in such a manner that in standing the plantar surface is everywhere in contact with the floor. With this the tarso-metatarsal and the metacarpo-phalangeal joints of the great toes appear greatly swollen.

³⁰ Pied tabétique—Revue de Médecine, 1884, p. 473.

There is less dispute concerning the nature of the so-called perforating ulcer of the foot. This lesion occurs only in cases where the central or peripheral nervous apparatus is diseased; thus, it may occur with neuritis, and it is therefore unanimously regarded as due to morbid nervous influences. In tabes it may follow an exacerbation of the fulminating pains. It consists in a swelling of the tissues of the foot; the skin becomes firm and thickened; deep sinuous ulcers are then developed, showing but slight if any tendency to granulate, and which extend down to the bone, the latter usually remaining unaffected.³¹ In a few cases more remarkable accidents due to disturbed nutrition have been noted. Thus, J. Hoffmann records a subcutaneous rupture of the Achilles tendon, and in another case the spontaneous discharge of all the teeth of the upper jaw within about a week's time.³²

³¹ Like most of the manifestations of advanced tabes, the perforating ulcer may occur exceptionally as a pre-ataxic symptom. Thus, Suckling (British Medical Journal, 1885, April 4, p. 693) mentions its preceding the development of tabes proper by one year.

³² Berliner klinische Wochenschrift, 1885, No. 12. In this unique case the loosening and falling out of the teeth preceded the tabes by a year. Demange, who observed the same phenomenon in two cases, found that the ascending root of the fifth pair was involved. The only analogous observation in my experience relates, like the bleaching of the hair in circular patches, to a case of spinal irritation: here the gums and alveolar borders underwent atrophy, exposing the roots of the teeth to beyond the normal alveolar border: first the right upper row, then the right lower row, and finally the teeth on the left side in the same order, showed this condition; only the most posterior fell out.

COURSE.—Tabes dorsalis is to be regarded as an extremely chronic affection. Its development, as previously stated, is insidious,³³ and the symptoms demonstrating the advent of the disease may be so slight for many years that the patient does not regard himself as ill or as likely to become so. In this condition he may remain for ten or more years; and there are cases recorded where the exact signs of the incipient stage were well marked, and yet no ascertainable progress was made in a period of such long duration that the inference naturally follows of a much longer prospective period in which the patient would not have become ataxic. There may be distinguished two forms of invasion: the more frequent is marked by the development of the terebrating, fulgurating, and fulminating pains, to which, sooner or later, the abolition of the pupillary and certain other deep reflexes is added. In the vast majority of cases they are found absent when the physician's attention is directed to the question of the existence of spinal disease. In about one-fifth of the cases pain is at no time a prominent feature of the disease, and may be, as is established by the cases cited, entirely absent. In these patients the first symptoms noted are muscle-tire on slight exertion. Usually, the evidences of disturbed sensation and innervation begin in one extremity or preponderate in it, but symmetry is soon established. The same is noticed in the extension of the morbid process: when the ulnar distribution is involved—which is the first danger-signal on the part of the cervical enlargement of the cord—usually one side is first involved, but the other soon follows, and becomes affected in equal or nearly equal degree. In the overwhelming majority of cases the disease manifests itself in the lower extremities first, remaining limited to them for a long period, and if extending to the upper extremities doing so in much slighter intensity than in the lower. Gull, Leyden, and others have observed cases where the arms were first and chiefly involved; but this is extremely rare. Cases of a simultaneous involvement of the upper and lower extremities are more frequently noted. The symptoms detailed above are developed in varying order in different patients, and the line has been already indicated which separates the progressive from the episodial features of the disease. Even in the ataxic period the patients may remain in a comparatively stationary period for many months and years.³⁴ The general bodily nutrition is usually good, and the muscular strength, as such, rarely affected to any noteworthy extent until the extreme phase of the disease is reached. Even the formidable-appearing crises and trophic disturbances, though occasionally fatal, are not always so. The direct danger from the disease proper, so far as life is concerned, is in the possible development of cystitis and pyelitis, of the malignant bed-sore, and of delirium and coma, the latter of which is occasionally found to be due to cerebral hemorrhage—a lesion which some writers regard as possibly due to some impalpable influence of the spinal disease on the cerebral circulation.³⁵

³³ Cases of acute locomotor ataxia have been described. In no instance are they pure or typical, and the last case of the kind published in America, beginning, as it is evident from the account, with signs of general myelitis, illustrates the impropriety of utilizing one or a few symptoms as determining nomenclature.

³⁴ Thirteen patients are now under my observation, or I have been able to obtain reliable medical information concerning their condition, who have been in the ataxic period since the date of my first examination, varying from a year to seven years ago. Not one of these patients is materially much worse than at that time. Two only died, both being bedridden at the time they came under observation. Of the first group, three have shown more or less lasting improvement in respect to special symptoms, as will be detailed in connection with the treatment.

³⁵ In a case of sudden death, with an asthma-like seizure, of a tabic patient under the charge of T. A. McBride, I found an intense injection of one (the right) vagus nucleus, the color of the ala cinerea and of the nucleus on section being almost black.

MORBID ANATOMY AND PHYSIOLOGY.—Our knowledge of the structural disease underlying the symptoms which comprise the clinical picture of tabes dorsalis is perhaps the clearest in the domain of spinal pathology. Not alone the commencement of the morbid process and every stage of its subsequent encroachment on the spinal cord, but also its relations to special symptoms, have been demonstrated in numerous cases by some of the most careful German and French investigators.

In advanced cases of tabes the disease of the spinal cord is so evident that it was noted even by earlier observers, the region of the cord lying between the posterior nerve-roots being altered in color, consistency, and dimensions. It is gray instead of white, hard instead of soft, and considerably shrunken. The gray discoloration of the surface appears to be complete in the lumbar and lower dorsal region; it is less intense in the upper dorsal and cervical part of the cord; and often shows a division into three streaks, of which one, in the middle line, occupies both columns of Goll, while on either side another extends in the inner side of the posterior root-entry. The posterior roots themselves are frequently atrophied, and exhibit a firmer consistency and darker color than in health. On making cross-sections of the spinal cord it is found that the gray discoloration extends inward, involving more or less of the posterior columns in well-defined areas. Microscopic examination shows that the myelin of the nerve-tubes is either destroyed or atrophied, and the axis-cylinder is found to be affected in the same way, usually presenting alterations in its refraction and diameter where it is not entirely destroyed. In the maximum foci of disease the conducting elements of the cord are nearly destroyed, and their place is occupied by a firm connective substance made up of wavy bundles, enclosing here and there a few atrophied axis-cylinders with wasted myelin-sheaths. The blood-vessels participate in the morbid process, at least as far as the larger vessels are concerned: these are sclerotic, their lumen appears contracted, the adventitial sheath is hypertrophied and occupied by a nucleated, fibrillar connective substance. The capillaries are sometimes normal, or participate in the morbid process to the extent of a thickening of the extra-endothelial sheaths which is either hyaline or fibrillary, and may show inflammatory cell-proliferation. It is evident that the increase of connective tissue in the posterior columns is not merely a relative one, due to the condensation of the normal neuroglia after the disappearance of the normal nerve-tubes, but is the result of actual proliferation. Opinion is somewhat divided as to whether this is to be considered as an inflammatory interstitial proliferation or as a more passive development of tissue compensating for the destroyed conducting elements. My own observations incline me to the belief that in syphilitic tabes the morbid process is essentially interstitial, while in non-syphilitic tabes it is parenchymatous, the disease beginning in the nerve-tubes proper. Perhaps the controversies between pathologists as eminent as Schultze, Tuczek, Rumpf, Zacher, Kahler-Pick, Rosenstein, and Adamkiewicz—who are rather evenly divided into opposing camps, one maintaining the parenchymatous, the other the interstitial, origin of the disease—may be solved when we learn to distinguish between the non-syphilitic and syphilitic cases, which is clinically, as yet, impossible. The difficulty of deciding what is a parenchymatous and what is an interstitial disease of the cord is considerably enhanced by the fact that the neuroglia, which by some at least is regarded as an interstitial connective tissue, is derived, like the nerve-substance proper, from the upper or neuro-epidermic germ-layer of the embryo, and not from the mesoblast, which furnishes all other connective substances in the body.

It is regarded as well established that the sclerosis of the areas of the spinal cord which are affected is preceded by a stage of granular degeneration.³⁶ This is supported by the facts that the sclerotic areas are surrounded by a zone in which sclerosis has not yet developed, but which is in a state of granular degeneration, and that in more advanced tabes this belt is also found sclerosed. In paretic dementia, a disease whose complicating cord affection closely resembles that of locomotor ataxia, a granular degeneration of the posterior columns is very common in earlier periods, while in later periods a sclerotic tissue is found in the same locality.

³⁶ Westphal, Archiv für Psychiatrie, ix. p. 725.

I regard these observations as opposed to the assumption of Strümpell that tabes is a system-disease of the cord in the sense in which he employs that term. In his fascinating and suggestive thesis on the systemic affections he cites the observations of Tuczek made on the posterior sclerosis ensuing from ergotism as confirming his view that special systems of nerve-fibres are separately vulnerable to special morbid influences. The remarkable correspondence between the topographical distribution of the lesion of ergotin tabes described by Tuczek and the characteristic areas of sclerosis found in the column of Burdach in ordinary tabes, seems to justify a very different conclusion. Ergot exerts its morbid influence through a disturbance of nutrition. Just as it produces gangrene by constriction of the nutritive vessels of the fingers and of whole extremities, so it produces interference with nutrition of those nerve-elements in the cord which are most liable to suffer from general arterial constriction. These are presumably those portions which are supplied by the longest and narrowest arterial stems—a condition obtaining in precisely those parts of the cord which are affected both in ergotin tabes and in ordinary tabes.

It has also been supposed that the morbid process began in the posterior roots and crept in with these, thence extending upward.³⁷ This view is opposed by the fact that there is no constant relationship between the root lesion and the cord lesion; the sclerosis of the root-zones within the columns of Burdach I found to be absolute in at least one case where the outer nerve-roots were not distinctly affected.³⁸

³⁷ Takacs is the most recent defender of this view.

³⁸ The root lesion may, like that of the column of Goll, according to a minority of the interpreters, be a secondary process, for in ergotin tabes (Tuczek) both are usually intact.

In typical tabes the sclerotic process begins in a special triangular field of the posterior column in the lumbar enlargement of the cord. The innermost of the posterior rootlets run through this field, which has been designated by the French school as the posterior root-zones, and the rootlets become exposed to all the vicissitudes which the conducting tracts are destined to undergo in consequence. Throughout the remainder of the cord it is the involvement of the root-zone which indicates the advance of the affection upward. At a time when the lesion is comparatively slight in the cervical level, manifesting itself by a slight grayish or reddish streak to the naked eye, a faint, pale discoloration in chromic-acid specimens, a deeper stain in carminized, and a pallor in sections stained by Weigert's method, the affected part in the lumbar region has undergone great shrinkage; scarcely a single myelin-tube is preserved to receive Weigert's stain within the affected area; the latter involves nearly the entire field between the cornua, and absorbs carmine deeply, so that it is difficult to differentiate the gray and white substance in carminized sections. A small part of the posterior column which most closely adjoins the posterior (gray) commissure remains free in all cases; so also does a small laurel-leaf-shaped field bisected by the posterior median septum. Examination with higher magnifying powers, aided by the modern improved methods of preservation and staining, reveals that the gray substance of the posterior segment of the cord is usually more or less diseased. In advanced cases the gelatinous as well as the spongy part of the posterior gray horn, and even the posterior gray commissure, undergo such considerable atrophy that they may occupy but half the normal area. In some cases the columns of Clarke appear to be involved quite early in the disease.³⁹

³⁹ Leyden discovered the degeneration in the fibres which in part make up these columns and correctly traced its origin to the posterior rootlets. Lissaner and Zacher (Archiv für Psychiatrie, xv. p. 437) confirmed him, the latter finding, as Leyden was the first to discriminate, that the cells may escape while the fibres are materially diminished. Krause claims that the columns of Clarke are constantly affected, but not necessarily in their entire length, the higher levels appearing quite normal at a time when the lower are severely involved (Neurologisches Centralblatt, 1884, p. 50).

The triangular field in the lumbar part of the posterior column, which is one of the typical starting-points of the affection, contains those ascending nerve-bundles which in their cephalic course emancipate themselves from the column of Burdach and constitute the slender columns of Goll. The result is that the degenerative process creeps up these columns at the same time that it ascends in the root-zones and deep portions of Burdach's columns. Some authorities regard this as a mere extension by contiguity;⁴⁰ others incline to consider it a secondary degeneration. It may extend to the medulla oblongata, becoming lost in the level where the nucleus of the column of Goll terminates, and is accompanied, at least in those advanced cases in which the upper extremities are involved, by a comma-shaped area of degeneration in the adjoining part of the column of Burdach, which similarly extends into the oblongata and terminates slightly more cephalad. In typical advanced tabes, therefore, the cross-section of the cord exhibits a characteristic distribution of the sclerosis in each level. As this distribution is associated with certain constant symptoms, it is permissible to attempt bringing certain features of the lesion in relation with special features of the disease symptoms. The posterior gray horns and the posterior white columns, together with other fibre-systems connected with them, are much more complicated in structural and physiological relations than the corresponding anterior structures. The relations of the anterior rootlets to the gray substance, and those of the motor ganglionic elements to their controlling tracts, are comparatively simple; those of the posterior roots are very intricate. They run up, in great part, at an angle to the longitudinal tracts; a few pass in directly, and still fewer dip to a lower level. The result is that a section of the cord made in the longitudinal direction through the root-zones, so as to pass from the root-entry to the anterior commissure, shows the column and root-fibres to be woven into each other like a plait. Trabeculæ of connective tissue, dragged in as it were with the posterior roots, fill up the interstices of this labyrinth. They are particularly dense in the lowest part of the lumbar enlargement of the cord, constituting the so-called posterior processi reticulares. It is reasonable to suppose that the overlapping of ascending and descending root-fibres, associated with the presence of an extra amount of connective tissue, imbedded as this fibre-maze is in that part of the cord which is most distant from its lymphatic emunctories, affords a favorable soil for slow inflammatory trouble. This is the primary field of tabic sclerosis, and in it the disease may remain most intense for years, extending but slowly and with diminishing intensity upward, hand over hand, as it were, on the natural ladder which the intertwined fasciculi and their matrix constitute. The longitudinal tracts which lie in and near the root-zones belong to the so-called short fibre systems, uniting the segments of higher and lower levels of the cord with each other. As the sclerotic process ascends it involves the caudal ends of these systems: they consequently undergo secondary degeneration, and, shrinking in their turn, affect the caudal part of the next system above in the same manner. The morbid process in the column of Burdach may therefore be considered as a combination of inflammatory and degenerative changes, the inflammatory products causing a series of short ascending degenerations, and the vulnerable path thus established being followed by a cirrhotic condition in which the connective and vascular structures participate actively. With regard to the reasons for regarding the degeneration of the column of Goll and that of the comma-shaped field near it as a secondary process due to the cutting off of its apparent nerve-supply at the caudal end, and of the posterior nerve-roots or their provisional terminations, they may be stated in this way: When the lesion of the primary field is limited to the lower lumbar or sacral part of the cord, the degeneration of the column of Goll is limited to its postero-internal part; when the upper lumbar and lower dorsal cord is involved, the entire tract is affected; and when the cervical portion is diseased, the supplementary comma-shaped area degenerates. In other words, the projection tract of the sciatic nerve, as far as it is represented in Goll's column, suffers in the first, that of the crural nerves in the second, and that of the brachial nerves in the third instance. In all advanced cases of tabes the affection of the column of Goll is in direct proportion to the altitude of the lesion in the primary field. Symptomatically, it bears an equally constant relation to the ataxia.⁴¹ No case is on record in which these columns were totally degenerated without some motor inco-ordination of the lower extremity having been observed during life; and no case is recorded in which brachial ataxia had been a marked and persistent feature in which the comma-shaped area—area of the column of Burdach—was healthy.

⁴⁰ It is held by them that the histological character of the change of the columns of Goll is not different from that in the column of Burdach. Zacher (Archiv für Psychiatrie, xv. p. 435) urges that it does not resemble true secondary degeneration, beginning in the vessels and connective substance instead of the nerve-fibres. Schultze (ibid., xiv. p. 386), on the other hand, recognizes a primary involvement of the nerve-fibres in both of the areas of fascicular degeneration in tabes. The observation of intact axis-cylinders by Babinski in the sclerotic fields is in conflict with the latter's claim, and the various differences of observation and interpretation seem to be reconcilable only on the assumption that there are two different modes of origin, both leading to nearly the same results and occasionally combined in one and the same case.

⁴¹ Krause's case and others show that the ataxia of movement is not influenced by lesion of the column of Clarke; but we are not informed as to the static equilibrium of the patients in whose cords these columns were found intensely affected.

It is scarcely necessary to seriously consider the suggestion of Strümpell, that the lesion of the column of Goll is in relation with the bladder disturbance.⁴² Cases are on record by Wolff and others where this lesion was intense and there was little or no bladder disturbance.⁴³

⁴² Archiv für Psychiatrie, xii.

⁴³ The column of Goll is not present in those mammals which, like the porpoise, have no developed hind limbs, but these animals have urinary bladders.

If the disease of the column of Goll were a primary systemic affection independent of the disease of the root-field, it would be difficult to understand why it, as well as the likelihood of finding a corresponding degeneration of the direct cerebellar tract, increases with the extent to which this field is involved. This occurrence becomes quite clear when we remember that both the direct cerebellar tract and that of Goll, being centripetal, are under the trophic dominion of the posterior nerve-roots. The opinion is not distinctly expressed, but implied in some writings, that the column of Goll degenerates because of a general transverse cord lesion at a low level; this is not the case in the tabic cord. There is a difference in appearance between that part of the primary field which corresponds to the column of Goll in the lumbar cord and the surrounding sclerosis in early cases: it is more intensely degenerated, more homogeneous in appearance, and more evenly stained. The other part of the triangular field presents a more trabecular appearance. In the specimen represented in the accompanying figure this is easily recognized: the darker field corresponds exactly with the ascending degeneration, which follows compression of the cauda equina,⁴⁴ and is the sciatic equivalent of the column of Goll.

FIG. 31.

Trans-section of Upper Lumbar Cord of a Patient moderately advanced in Tabes: f, ventral or anterior fissure; g, caput gelatinosum; r r′, entry and deep course of the posterior rootlets; d, degenerated field, including the origin of the tracts which in higher levels form the columns of Goll; n, field near the posterior commissure which remains free from degeneration, both in the lumbar and cervical cord; s, sharply marked leaf-shaped field, bisected by posterior septum, which, as claimed by Strümpell and shown in this case, remains free from disease; z, zone of nearly normal consistency around it; a, diseased field, suspected to be related to the analgesia, not usually affected in early tabes; v, fibres running up and down in front of the gelatinous substance; *, region where the tabic process sometimes begins.

⁴⁴ I have also found that this field corresponds to the column of Goll in its myelinic development: the lumbar part of this column—designated as such by Flechsig—is an entirely different tract, which enjoys a remarkable immunity from disease in tabes.

As illustrating the bearing of the lesion of the column of Goll on the motor ataxia I may refer to two cases which happen to be related side by side by Strümpell (Archiv für Psychiatrie, xii. p. 737, Cases 1 and 2). As far as the lumbar segment of the cord is concerned, the distribution of the lesion is similar; but in the one presenting marked motor ataxia the triangular field was slightly diseased, and there was no upward extension of the lesion in the column of Goll. In the other, with marked ataxia, the triangular field was intensely diseased, and ascending degeneration (?) occurred in the sciatic fields of the latter.

In support of the view that the comma-shaped area in Burdach's columns is homologous with the fibres of the column of Goll, it is to be advanced that degeneration of this field bears the same relation to symptoms in the distribution of the ulnar nerve that degeneration of the column of Goll bears to sciatic and crural symptoms. Where the initial pains and subsequent tactile and locomotor disturbance were severe, this field was found affected, and most so in the side where the symptoms had been most intense (Friedreich-Schultze's cured cases, Archiv für Psychiatrie, xii. p. 234). This area has no direct connection with the root-fields. Secondly, in a primary system disease of the column of Goll, associated with degeneration of the nucleus of the column of Goll, described by Scoli, an irregular encroachment of the column of Burdach was noted. Third, the innermost fibres of the column of Burdach (those belting the nucleus in the oblongata) have the same relation to the interolivary layer which the column of Goll has through its provisional nucleus of termination.

While the evidence of high lesion of the cerebral continuation of the column of Goll, and, what I regard as its homologue, the comma-shaped area of Burdach, together with the constant association of marked degeneration of these columns with motor ataxia, is strong positive proof of its relation to this symptom, there is equally strong evidence negativing its relation to any other of the prominent symptoms of tabes dorsalis. Thus Babesin (Virchow's Archiv, lxxvi. p. 74) found degeneration of the posterior columns limited to the column of Goll, and the patellar reflex was not destroyed; the root-fields at the upper lumbar levels were intact. That the columns of Goll have been found profoundly affected without bladder disturbance has been stated previously, and constitutes a stronger argument against Strümpell's view than the frequent observation of bladder trouble in spinal diseases, along with which these columns may be entirely free.

Among the various constituents of the posterior columns which appear to present a relative immunity to the disease, aside from the area near the posterior commissure and the laurel-leaf-shaped area of the posterior septum, Strümpell noted one which is situated at the periphery of the cord, bordering on the entry-line of the posterior roots and the inner contour of the posterior roots. In the few cases where it was found destroyed there was, what is a comparatively rare thing in moderately severe tabes, complete analgesia. It is not, however, certain that there is a necessary connection between the pathological and clinical fact here. The nerve-roots themselves are involved within the diseased area of the root-zones. The lesion is one of a kind which, affecting a nerve-trunk, would produce first irritation of, then impediment to, and ultimately destruction of, its function. The clinical parallel to this is the occurrence of the lightning-like pains in the earlier phases of the disease, which are followed by delayed pain-conduction, and finally by loss of sensation. Of the rootlets or fibres subservient to the various sensory and reflex functions mediated by the posterior roots, those which convey the centripetal impression normally evoking the patellar jerk appear to be the most vulnerable, or, because of their limited number, the earliest to be destroyed or compressed, with the result of total functional paralysis.⁴⁵

⁴⁵ It is now conceded that, as Westphal claimed, the patellar jerk is always abolished when the upper lumbar level of the root-zones (bandelettes externes of Charcot) is involved. Tshirijew has shown that the translation of the knee-jerk reflex occurs in a single segment of the rabbit's cord at the homologous level. In transverse sections a distinct fascicle may be seen coursing from the innermost root-fibres toward the antero-intermediate cell-group of the anterior horn; it furnishes a pictorial substratum, if not anatomical proof, for the patho-physiological observation, and harmonizes with the fact that it is the innermost rootlets which usually suffer first. Perhaps the delicacy of this tract accounts for the frequent disappearance of the jerk in old people as a result of senile sclerosis.

With regard to the interpretation of the various tactile sensory disturbances of tabes and the delayed pain-sense conduction little positive advance has been made. That the lesion of the root-zones and gray substance is responsible for them seems to be the general conclusion of French and German observers. Recent researches have shown that disease of the peripheral nerves (multiple neuritis) may produce sensory phenomena which it had previously been customary to regard as pathognomonic of disturbance of their intraspinal terminations and continuations. At the same time, we are confounded by the observation of Erb, that even retardation of conduction of the pain-sense, which the dictum of Schiff taught us to regard as a sign of disturbed function of the spinal gray matter, is also produced by peripheral neuritis.

Immediately adjoining the gelatinous apex of the posterior horn there is a column of vertical fibres which bear a relation to it resembling that of the ascending root of the fifth pair in the oblongata to the tuber cinereum of Rolando. Sclerosis of this column, as well as of the ascending root in question (Demange), has been found in tabes, and usually in association with pronounced trophic disturbances. In a number of cases (Oppenheim, Eisenlohr, and others) where spasmodic laryngeal crises had been a marked feature during life, lesion of the floor of the fourth ventricle, or atrophy of the pneumogastric nerve, or even of its nucleus, was found. In one case with marked gastric crises I found sclerotic changes of the arteries in the ala cinerea.

With regard to the involvement of the peripheral nerves proper, aside from the optic, opinion is somewhat divided. The discovery of multiple neuritis, and the recognition of the fact that it had been erroneously confounded with tabes, led Dejerine to claim that tabes might be of peripheral origin. He even proposed to account for the oculo-motor trouble on the basis of an affection of the oculo-motor nerves. This explanation has been repudiated by Westphal and sound authorities generally. That the peripheral nerves are occasionally involved in tabes was already known to Friedreich in 1863,⁴⁶ and later Westphal found the cutaneous branches in an advanced tabic patient to present similar changes to those discovered by Friedreich: these findings are confirmed by his Japanese pupil, Sakaky. The nerve-tubes are atrophied, the axis-cylinder being often preserved, and the interneural connective substance is proliferated. But there is no constant relation between these changes and the symptoms of the disease; in one of Sakaky's cases the nerves of an extremity which had been the seat of severe sensory symptoms were entirely normal. The findings in the peripheral nerves of tabic subjects lose much of their value in view of their recent discovery in marantic persons⁴⁷ advanced in life, but who had no nervous disease whatever.

⁴⁶ Virchow's Archiv, vol. xxvi. pp. 399-452.

⁴⁷ Krause, Neurologisches Centralblatt, 1885, p. 53.

It has been attempted to bring the tabic process in relation to a supposed primary meningitis. Tabes is a rather common nervous affection, and primary spinal meningitis is one of the very rarest. The leptomeninges are found considerably thickened in one out of ten tabic cords, and those who defend the meningitic origin of the disease base their theory on this inconstant finding, and allege that in the cases where it is absent the meningitis has disappeared while the cord lesion progressed. It is a fatal objection to this view that the part of the posterior columns immediately adjoining the pia is often quite free from disease. A meningitic affection, either as an etiological or a complicating factor, can be admitted in those cases only where there is a marginal sclerosis.

The changes in the optic nerve resemble those of the white columns of the cord in their naked-eye and minute character as well as in the controversial nature of the various interpretations made. When affected, the nerve is found to be firmer than normal, and discolored; later it becomes quite gray, and may eventually shrink to two-thirds, and even less, of its normal diameter. It is generally believed that, as in the cord, the myelin undergoes wasting before the axis-cylinder disappears, and that the latter may survive a long time, thus explaining why the patient may retain his visual power for a considerable period after the ophthalmoscope determines the existence of atrophy. No satisfactory explanation has as yet been offered for the optic-nerve affection of tabes. There is no direct continuity of the spinal and optic sclerosis. Two theoretical possibilities suggest themselves. The first is that the lesion of the cord exerts a remote effect upon the physiological, and through this the structural, condition of the optic nerve. That such an influence may be exerted is shown by cases of transverse myelitis low down in the cord, which, according to Erb and Seguin, were complicated by double optic-nerve atrophy. The second theory is that the involved part of the cord and the optic nerve present a similar vulnerability to the same morbid influences. This is illustrated in some cases of chronic alcoholic and nicotine poisoning, in ergotism, and in the spinal affections due to hereditary influences and developmental defects.

To discuss the nature of the disturbing influence which is responsible for the most characteristic evidence of the disease, the ataxia, would be equivalent to reviewing almost every mooted question in spinal physiology. It is to be borne in mind that ataxia is a collective term designating any inco-ordination of movement which is independent of motor paralysis. It may be due to abolition or impairment of tactile perception; it may be due to loss of the muscular sense; it may be due to hampered motor co-ordination; and, finally, it may be due to a disturbance of the space-sense. In my opinion it is only in exceptional cases that any one of these factors can be positively excluded. Occasionally, one has been noted when the ataxia was grave but the tactile sense was unimpaired, or where the muscular sense was perfect but ataxia was well developed. The difficulty with most such records is that no discrimination is made as to the kind of ataxia present. That loss of skill which the patient shows when he shuts his eyes and attempts to perform certain movements without their aid is undoubtedly due to diminished sensation, either tactile or muscular, and usually both. The inability to stand with the eyes closed is probably a cerebellar phenomenon, and in this respect we are on the way to return to Duchenne's opinion. It is true that the cerebellar organ is healthy in most tabic subjects, but its centripetal informer, the direct cerebellar tract, is either itself involved or affected in its origin in the columns of Clarke. But, besides the static ataxia and that motor ataxia which can be neutralized by the use of the eye, there is another disturbance, which, as Erb and his followers hold, cannot be accounted for on the strength of any sensory disturbance. It consists in an interference with the proper succession and rhythm of movement. It seems as if that automatic mechanism by which the individual or grouped muscular contractions engaged in locomotion follow each other with the smoothness of the action of perfectly-fitting cog-wheels were disturbed; the correct after-movement is hesitated over or skipped, or even takes place at the wrong moment, neutralizing some other step in the co-ordination required. The tendency of physiologists and pathologists is to attribute this form of ataxia to the disease of the intrinsic co-ordinating apparatus of the cord itself. The experiments of Tarchanoff on a headless duck, and the determination of the existence of cursorial co-ordinating tracts uniting the brachial and lumbar nuclei in mammals, as well as the observations made on automatic co-ordinate movement in decapitated criminals, demonstrate the existence in the cord of such an apparatus. The combination of the ganglionic centres which underlies this co-ordination is affected by the so-called short tracts of the cord,⁴⁸ and it is precisely a portion of these which are involved in the lesion of the column of Burdach. A number of arguments have been advanced against regarding the lesion of this column, or indeed any of the lesions of the posterior column, as explaining the ataxia-producing effect of tabes. Westphal has interposed some potent objections. He holds that lesion of these columns will be found more frequently when examinations shall no longer be limited to those cases where disease is suspected because ataxia was observed during life. He found extensive disease of the posterior columns in sufferers from paretic dementia who did not exhibit the characteristic ataxic gait of tabes. I believe this objection can be met by the very cases cited by Westphal in its support. Where the spinal disorder preceded the cerebral—that is, where paretic dementia occurred as a complication of tabes dorsalis—true locomotor and static ataxia had been present before the insanity exploded. On the other hand, where the spinal disease followed the cerebral, typical ataxia did not ensue. This would seem to indicate that the destruction of cortical control is inimical to the development of typical tabes. Leyden has made a suggestion in the same direction when he attributes the lesser manifestness of locomotor ataxia in tabic females to their inferior cerebral organization.⁴⁹ A more convincing proof of the correctness of this conclusion is furnished by the fact that if the pathological process, after destroying the posterior columns and producing ataxia, invades the voluntary motor tract, the ataxic symptom becomes less palpable.⁵⁰ This antagonism between lateral-column and posterior-column lesion is frequently exemplified in the combined forms of sclerosis. It would seem, then, that where the brain is healthy and the controlling voluntary tracts are unimpaired, the ataxia is aggravated, supporting the beautiful theory of Adamkiewicz, which assumes that the locomotor ataxia is due to a disturbance of the balance normally existing between the psycho-motor centres and those controlling the muscular tone as well as those mediating reflex excitability.⁵¹

⁴⁸ Intersegmental tracts.

⁴⁹ In one out of three female eases I found the active disturbance of gait as severe as in males, but Leyden's observation is supported by all who have seen a sufficiently large number of female cases.

⁵⁰ Not because of paresis altogether, for it diminishes materially out of proportion to the paresis.

⁵¹ Archiv für Psychiatrie, x. p. 545. There is another observation which bears in this direction: James of Boston observed that absolute deaf-mutes in a large percentage of cases are insusceptible to vertigo or to the allied phenomenon of sea-sickness. Certainly, the auditory nerve is a space-sense nerve; its physiological elimination is, however, accompanied by an immunity against a symptom which may be an evidence of disturbed space-sense transmission. In like manner, the destruction of the central perceptive and voluntary centres in the paretic dement inhibits the legitimate results of posterior spinal sclerosis.

The degeneration of the crossed-pyramid tracts in typical tabes seem to be strictly an atrophy from disuse, perhaps facilitated by the general malnutrition of the cord. It is limited to that part supplying the most or solely affected extremities. Thus, where the lower extremities are alone grossly involved it is totally degenerated in the lumbar area, and only in its outer parts in higher levels. As if to fortify this comparison by analogous observations from every great segment of the nervous axis, a similar inhibiting influence of pyramid lesion on co-ordinating disturbance (muscular sense) is noted in secondary degeneration of the interolivary layer; when uncomplicated with pyramid lesion (Meyer and my own case,) ataxia is present; when so complicated (Schrader, Homén) it is not observed, even if determinable.

Lissauer⁵² has recently determined the existence of a degeneration of certain fine nerve-fibres, apparently derived from the outermost of the radicles into which the posterior nerve-roots divide on entry. They are situated on that border of the apex of the posterior horn which is in contact with the lateral column, and were found degenerated in all cases except such as were in the initial period. No symptomatic relation has been claimed for this lesion.

⁵² Neurologisches Centralblatt, 1885, No. 11.

One of the most important questions which have grown out of the pathological studies of tabes is the relationship between the lesions and the not infrequently observed restoration of functions which had been more or less seriously impaired in an earlier period of the disease. Even those symptoms which ordinarily comprise the continuous and essential clinical background of tabes may exhibit remarkable changes in this direction. I have two well-established observations—one of tabes of eight years' standing, the other of more recent date—in which that symptom which, once established, is the most constant, the reflex iridoplegia, disappeared, to reappear in two months in one case where it had been associated with myosis, and to reappear in eight months in the other, repeating this oscillation the following year. I have now under observation a tabic patient in the sixth year of his illness who two years ago had a return of both knee-phenomena to a nearly normal extent, to lose them in two months, and to regain the reflex on the left side four months ago, retaining it up to the present. These three cases were of syphilitic subjects. In a fourth advanced non-syphilitic tabic patient, whose ataxia had reached a maximal degree, I found a return of both knee-phenomena for three days after its absence had been established by medical examiners for over a year, and had probably been a feature for a much longer period. Hammond the younger and Eulenburg have reported similar cases. Nothing is more surprising to those unfamiliar with the progress of this disease than to find gross ataxia or the electrical pains and anæsthesia to disappear or nearly so; and the alleged success of more than one remedial measure is based on the fallacious attributing to the remedy what was really due to the natural remittence of the disease-process or of its manifestations. The financial success of quacks and the temporary but rapidly evanescent popularity of static electricity, Wilsonia belts, and like contrivances are owing to the hopefulness inspired in the credulous patient by the mere coincidence of spontaneous improvement and the administration of a new remedy, supplemented, it may be, by the influence of mind on body in his sanguine condition. It is to be assumed that the influences which are at work in provoking the trophic and visceral episodes of tabes are of an impalpable character, and that all theorizing regarding the reason of their preponderance in one and their absence in another case are as premature as would be any speculation regarding their rapid development and subsidence in the history of one and the same case. But we have better grounds for explaining the remissions of the ataxia and anæsthesia.

It is only in the most advanced stages of tabes that the destruction of the axis-cylinder becomes absolute or nearly so. Contrary to the opinion of Leyden,⁵³ who held that the tabic sclerosis differs from disseminated sclerosis in the fact that the axis-cylinder does not survive the myelin disappearance, it is now generally admitted that a certain number of exposed or practically denuded axis-cylinders may be preserved in the sclerotic fields.⁵⁴ It is on the theory that these delicate channels may be oppressed at one time, perhaps by inflammatory or congestive pressure, and relieved at another by its subsidence, that we may assume them to be the channels through which the now limited, now liberated, functions are mediated. It is also reasonable to suppose that vicarious action may supplement the impaired function, and to some extent overcome the disturbing factors. This is illustrated by the controlling influence of the visual function—yea, even of the unconscious and ineffectual co-operation of completely amaurotic eyes—in neutralizing both locomotor and static ataxia. One patient who was well advanced in the initial period of tabes, and who had been encouraged to consider the medical opinion to that effect as the result of an exaggerated refinement of diagnosis, made repeated tests of the Romberg symptom in his own case, and deluded himself into the belief that the physician was mistaken because he succeeded in practically overcoming it with an effort that too plainly told its own story; but still he overcame it. Certain peripheral influences have the power of stimulating the dormant activity of potentially vicarious tracts, and perhaps also the blunted activity of those whose function is impaired. The outside temperature, certain barometric conditions, all may exert an influence in this direction for good or evil.

⁵³ Op. cit., p. 328, vol. ii.

⁵⁴ Babinski (Neurologisches Centralblatt, 1885, p. 324) notes this feature, and, consistently with the findings of most modern observers, discovers much more resemblance to disseminated sclerosis than to the systemic sclerosis with which Strümpell and Westphal (in part) incline to classify tabes. Similar objections to the system-disease theory are advanced by Zacher (Archiv für Psychiatrie, xv. p. 340). I may not pass over in silence the fact that Babinski considers his observations to militate also against regarding any phase of the tabic sclerosis as a secondary process. But while it may fairly be asked that a sclerosis to be regarded as systemic must be shown to be total, this is not necessary for a secondary process, unless the primary involvement be total also; and that is not the case in tabes.

ETIOLOGY.—Authorities are now agreed that no single cause can be regarded as the sole responsible factor in all cases of tabes, and that a number of etiological influences are combined in the provocation of this disease in most instances. When the distinctiveness of the affection was first recognized it was customary to attribute it to sexual excesses, and the unfortunate sufferer had frequently to bear the implied reproach of having brought his misery on himself, in addition to the hopeless prospect which those who followed Romberg and other authorities of the day held out to him.⁵⁵

⁵⁵ This opinion survives in a large portion of the German laity and in French novels. About the time that the poet Heine was dying from an organic spinal affection two other prominent literary characters of Paris were affected with tabes. It so happened that all three were popularly regarded as libidinous, and one of their leading contemporaries, whose name escapes me, took occasion to issue a manifesto addressed to the jeunesse dorée which closed with the apostrophe, “Gardons à nos moelles.”

Heredity plays a very slight part in the etiology of tabes. Writers of ten and fifteen years ago attributed a greater importance to it than is now done. But this was due to the incorporation with tabes of the so-called family form of locomotor ataxia—a disease which is now regarded as a distinct affection.⁵⁶

⁵⁶ There is but one record of direct heredity (the father and son being affected nearly at the same time), to my knowledge. It was observed at the Berlin Hospital by Remak (Berliner klinische Wochenschrift, 1885, No. 7). Both father and son were syphilitic.

More importance may be attached to individual predisposition, but thus far no distinct formulation of this factor has been attempted except by Schmeichler,⁵⁷ who offers the suggestion that there are persons with a predisposition to the development of connective-tissue proliferation in various organs of the body, and that in them tabes and other sclerotic affections are consequently more frequent than in others. This suggestion appears plausible, but it is unconfirmed by positive observations.

⁵⁷ Op. cit.

Sex appears on a superficial view to be one of the most important elements. It is generally admitted that at most one female becomes tabic for every ten males who do so. Of 81 cases in private practice, I observed but 3 females. Rockwell, Seguin, Birdsall, and Putnam give similar figures. This comparative immunity is probably due to the fact that the female is less exposed to over-exertion, to surface chilling of the feet, to the injurious consequences of sexual excess, and to syphilis⁵⁸ than the male. As a rule, the affection in females is more insidiously developed, progresses more slowly, is less marked by crises and trophic disturbances, and not accompanied by as severe pains and profound disturbance of co-ordination as is the corresponding affection in males.

⁵⁸ Whether the shorter vitality of the syphilitic female as compared with that of the male is a factor in diminishing the accumulation of chronic tertiary sequelæ in that sex, or whether it be the lesser vulnerability of the inferior nervous system, I am unable to decide from the facts at my disposal. In private and clinical experience I have been struck by the fact that women affected with syphilis in the same way and under similar circumstances with tabic syphilitic males develop symptoms of functional disorder of the brain and cord, such as spinal and cerebro-spinal irritation. My cases referred to had in no instance any indication of a syphilitic condition or history, and a distinct and different cause was found in all three.

The most important element in creating an acquired predisposition to tabes is undoubtedly the existence of constitutional syphilis. Some difference of opinion still exists regarding the proportion of syphilitic tabic patients, chiefly due to the neglect of Erb—when he first announced the prevailing view, and which is generally attributed to him—to differentiate between cases of demonstrated constitutional syphilis and the so-called spurious or soft chancre. But although there occurred a reaction against his view which went to as great an extreme in the opposite direction, the careful and critically registered statistics accumulated in the mean time strengthen the view that there are more syphilitic subjects among the tabic than among any class of sufferers from other nervous affections.⁵⁹ Reumont, a physician at Aix-la-Chapelle, to which place syphilitic patients in general resort in large numbers, found that of 3400 cases of syphilis, 290 had nervous affections, 40 being afflicted with tabes. Bernhardt⁶⁰ took occasion to examine a group of hospital patients who were free from tabes, and found that not fully 16 per cent. were syphilitic, while of 125 tabic patients, over 46 per cent. were determined to have had positive syphilitic manifestations. Several of those observers who have paid attention to the question of the syphilitic origin of tabes have admitted that the more searching their inquiry the larger the proportion of detected syphilitic antecedent histories. Thus, Rumpf's earlier table shows 66, and his later 80, per cent. of such antecedents. This latter figure exactly corresponds to the percentage of syphilis in my private cases. At a discussion held by members of the American Neurological Association in 1884, Webber gave 54, Putnam 49, Rockwell 40, Birdsall 43,⁶¹ and Seguin 22 per cent.⁶² as the proportion in their experiences.

⁵⁹ Excepting always those having the distinctive and undisputed syphilitic character.

⁶⁰ Archiv für Psychiatrie, xv. p. 862.

⁶¹ Derived from over five hundred cases which had presented themselves at the clinic of the College of Physicians and Surgeons.

⁶² In the Archives of Medicine he tabulates 54 (private) cases as follows:

Chancre alone	23
Chancre followed by secondary symptoms	16
Total of those with history of chancre	39
No history of chancre in	15
Total	54

Of European writers, aside from those already mentioned, Berger claims 43 per cent., and Bernhardt, in commenting on the increasing percentage obtained by accurate investigation, reports an additional series of 7 new cases in private practice, all of which were syphilitic. Fournier, Voigt, Œhnhausen, and George Fisher estimate the syphilitic tabic patients at respectively 93, 81, and 72 per cent. of the whole number. The almost monotonous recurrence of a clear syphilitic history in my more recent records is such that in private practice I have come to regard a non-syphilitic tabic patient as the exception. Among the poorer classes the percentage of discoverable syphilitic antecedents is undoubtedly much less. The direct exciting causes of tabes, exposure and over-exertion, are more common with them and more severe in their operation.

The proof of a relationship between syphilis and tabes dorsalis does not rest on statistical evidence alone. A number of observations show that the syphilitic virus is competent to produce individual symptoms which demonstrate its profound influence on the very centres and tracts which are affected in tabes. Thus, Finger⁶³ showed that obliteration of the knee-jerk is a frequent symptom of the secondary fever of syphilis, and that the relation is so intimate between cause and effect that after the return of the reflex, if there be a relapse of the fever, the obliteration of the knee-jerk is repeated. Both the permanent loss of the knee-jerk (Remak) and the peculiar pupillary symptoms of tabes are sometimes found in syphilitic subjects who have no other sign of nervous disorder; and Rieger and Foster⁶⁴ regard the syphilitic ocular disturbances, even when they exist independently, as due, like those of tabes, to the spinal, and not to a primarily cerebral, disturbance. Another argument in favor of the syphilitic origin of tabes is derived from the occasional remedial influence of antisyphilitic treatment. The force of this argument is somewhat impaired by the fact that the same measures occasionally appear to be beneficial in tabes where syphilis can be excluded. Still, the results of the mixed treatment in a few cases of undoubted syphilitic origin are sometimes unmistakable and brilliant.⁶⁵ As some cases, even of long standing, yield to such measures, while others, apparently of lesser gravity and briefer duration, fail to respond to them, the question as to whether syphilis is a direct cause or merely a predisposing factor may be answered in this way: That in the former class it must have been more or less directly instrumental in provoking the disease, while in the latter class it is to be regarded as a remote and predisposing factor, to which other causes, not reached by antisyphilitic treatment, became added. The claim of Erb, that “tabes dorsalis is probably a syphilitic disease whose outbreak is determined by certain accessory provocations,” is not subscribed to unreservedly by a single writer of eminence.

⁶³ “Ueber eine constante nervöse Störung bei florider Syphilis der Secundärperiode,” Vierteljahrschrift für Dermatologie und Syphilis, viii., 1882.

⁶⁴ “Auge und Rückenmark,” Graefe's Archiv für Ophthalmologie, Bd. xxvii. iii.

⁶⁵ In one case already referred to a return of both knee-phenomena and complete disappearance of locomotor and static ataxia were effected after a duration of four years. The treatment was neglected and the knee-jerks disappeared, and one has now returned under the resumed treatment, but accompanied by lightning-like pains. At a meeting of the Société médicale des Hôpitaux, held November 10, 1882, Desplats reported a case in which even better results were obtained. Reumont (Syphilis und Tabes nach eigenen Erfahrungen, Aachen, 1881) reports 2 out of 36 carefully observed syphilitic cases cured, and 13 as improved under antisyphilitic treatment.

The question has been raised whether the influence of syphilis is sufficiently great to justify a clinical demarcation between syphilitic and non-syphilitic cases. A number of observers, including Reumont, Leonard Weber, and Fournier, incline to the belief that there are more atypical forms of tabes in the syphilitic group. Others, including Rumpf, Krause, and Berger, are unable to confirm this, but the former admits, what seems to be a general impression among neurologists, that an early preponderance of ptosis, diplopia, and pupillary symptoms is more common with syphilitic than with non-syphilitic tabes. Fournier⁶⁶ believes that syphilitic patients show more mental involvement in the pre-ataxic period; but it is evident that he has based this belief on a study of impure forms. The advent of tabes in syphilitic cases does not in this respect differ from the rule. The most protracted and severe diplopia I have yet encountered in a tabic patient is one, now under observation, in the initial period of the disease, syphilis being positively excluded as an etiological factor.

⁶⁶ L'Éncephale, 1884, No. 6.

It seems to be a prevalent opinion that the cases of syphilis in which tabes is developed include a large proportion of instances in which the secondary manifestations were slight and unlike that florid syphilis with well-marked cutaneous and visceral lesions which is more apt to be followed by transitory or severe vascular affections of the cord and brain.

Excesses in alcohol, tobacco, and abuse of the sexual function are among the factors which frequently aggravate the tendency to tabes, and one or more of them will usually be found associated with the constitutional factor in syphilitic tabes. Both alcohol and nicotine have a deleterious effect on nervous nutrition and on the spinal functions, as is illustrated in the effect of the former in producing general neuritis, and of both in provoking optic-nerve atrophy and general paralysis of the insane, not to speak of the pupillary states which often follow their abuse, and the undeniable existence of a true alcoholic ataxia. Sexual excesses were, as stated, at one time regarded as the chief cause: the reaction that set in against this belief went to the extreme of questioning its influence altogether. It is to-day regarded as an important aggravating cause in a large number of cases, and this irrespective of whether it be the result of a satyriacal irritation of the initial period or a precedent factor. In a large number of my patients (18 out of 23 in whom this subject was inquired into) the habit of withdrawing had been indulged in,⁶⁷ and, as the patients admitted, with distinct deleterious effects, such as fulness and throbbing in the lumbo-sacral region, tremor and rigidity, with tingling or numbness, in the limbs, blurred vision, and sometimes severe occipital headache; in one case lightning-like pains in the region of the anus ensued.⁶⁸

⁶⁷ Coitus reservatus, the real crime of the Onan of Scripture.

⁶⁸ Leyden states that coitus in the upright position has been accused of producing tabes, without mentioning his authority. I have no observation on this subject touching tabes, but am prepared to credit its bad effect from the account of a masturbator, who during the orgasm produced while standing felt a distinct shock, like that from a battery, shooting from the lumbar region into his lower limbs, and causing him to fall as if knocked down. He consulted me in great alarm—was scarcely able to walk from motor weakness, and had no knee-phenomenon; in a few weeks it returned, and no further morbid sign appeared. Masturbators of the worst type occasionally manifest ataxia, and in three cases I have been able to establish the return of the knee-jerk, together with other improvements in the spinal exhaustion of these subjects. The loss and diminution of the patellar jerk, and the frequently associated urinary incontinence, as well as certain of the peripheral pains found in masturbators, certainly prove that undue repetition of the sexual act (be it natural or artificial) is competent to affect the cord in a way that cannot but be injurious in case of a predisposition to tabes, if not without the latter.

Of single causes, none exerts so direct and indisputable an influence on the production of tabes as the action of cold and wet upon the lower segment of the body. It is usually the case that such exposure is frequently repeated and combined with over-exertion before the disease is produced, but it is occasionally possible to trace the very first symptom of the disease directly to a single exposure. A soldier who stands up to his knees in a rifle-pit half full of water finds his limbs numb or tingling; develops slight motor weakness, then lightning-like pains, and ultimately a typical tabes. In the case of a peddler who presented an advanced form of the disease, the first symptoms had developed after a single wetting of his feet: while walking along one of our watering-places with his wares the swell of a steamer inundated the beach. He had been subject to perspiring feet before that, and the perspiration remained checked from that time on.⁶⁹ The influence of surface chilling was remarkably manifest in all three of my female cases. In one of them it was due to frequent wetting of the feet; in the second, a midwife, the first symptoms began immediately after standing on a cold hearthstone while preparing some article needed in a lying-in case. In the third case, a lady who contracted and safely passed through a scarlatina in her twenty-eighth year was taken out driving while desquamation was going on. She became thoroughly chilled, experienced numbness in the fingers and toes, and from that day on developed a slowly progressing tabes involving all extremities alike.⁷⁰

⁶⁹ Checking of habitual perspiration by violent measures is mentioned by the German textbook writers as a frequent cause, but occurs quite rarely in the modern tables.

⁷⁰ In view of the absence of spinal—or, in fact, any nervous—symptoms prior to the exposure referred to, it does not seem necessary to insist that this was not an instance of a true post-scarlatinal tabes; and possibly the case thus designated by Tuczek (Archiv für Psychiatrie, xiii. p. 147) may have been really due to chilling of the delicate body-surface after desquamation or during that process. The typical form of myelitis and sclerosis after exanthematous fevers is rather of the disseminated type.

Spinal concussion has been mentioned by a number of authorities as a possible cause for tabes, as for other forms of sclerotic spinal disease. In 1 of 81 cases in my own observation the development of the disorder could be distinctly traced to a railway injury; in 2 a sudden aggravation was as distinctly referable to a similar cause.⁷¹ To what extent railroad travelling, with its attendant continual jarring of the body, may predispose to the development of tabes or of other spinal diseases is as yet a matter of mere conjecture. That railroad travelling exerts a bad influence in some cases of the established disease is evident; but in others the patients rather like the motion, and claim to feel benefited by it.

⁷¹ A fall from a chair, striking on the back of the latter, while endeavoring to keep a row of books from coming down in one case, and the shock of the Ashtabula disaster in the other. The latter patient, the same one who is referred to as describing the electric-storm sensation in an earlier part of this article, had his foot amputated in consequence of that disaster; but, like one of the characters in Jacob Faithful, who felt his toes when the weather changed, though he left both legs at Aboukir, he felt the terrific pains of the disease in the absent foot as distinctly as in the other. Dumenil and Petit (Archives de Névrologie, ix. Nos. 25 and 26) relate cases in which a spinal concussion was the only ascertainable cause.

A number of toxic agents have been charged with producing tabes: thus, Bourdon maintains this of absinthe; Oppenheim attributes one case to poisoning by illuminating gas, the exposure to its influence being immediately followed by a gastric crisis, and this by a regulation tabes.⁷² It is supposed that most of the poisons acting on the cord in this or a similar way, such as arsenic, cyanogen,⁷³ barium, and chloral,⁷⁴ do not produce a spinal lesion directly, but through the medium of a secondary cachexia. Of no agent is the effect in producing tabes so well studied as ergot of rye. It had long been known that ergot-poisoning provoked certain co-ordinating, motor, and sensory disturbances, but it was left for Tuczek⁷⁵ to show that this vegetable parasite produces a lesion of the spinal cord which in its character and distribution apes typical posterior sclerosis so closely as to justify the designation of a tabes ergotica. Possibly, pellagra, which is sometimes manifested in a similar way,⁷⁶ may yet be shown to have a like influence.

⁷² Archiv für Psychiatrie, xv. p. 861.

⁷³ Bunge, Archiv für experimentelle Pathologie, xii.

⁷⁴ Transactions of the Clinical Society of London, xiii. p. 117, 1880.

⁷⁵ Archiv für Psychiatrie, xiii. p. 148.

⁷⁶ Bouchard, “Étude d'Anatomie pathologique sur un Cas de Péllagrie,” Gaz. méd. de Paris, 1864, No. 39.

Among the occasional and exceptional causes of tabes, Leyden and Jolly mention the puerperal state; Bouchut, diphtheria; and several instances are recorded in which psychical shock was responsible for the outbreak of the disease. In a small number of cases I found that mental worry and anxiety coincided with the period of presumable origin of the disease.

Age seems to have no special determining influence. It is true that most sufferers from this disease are men in the prime of life or in the period following it. But it is precisely at these periods that the exposure to the recognized causes of tabes is greatest. It seems as if there were very little liability to the development of tabes after the fiftieth and before the twenty-fifth year; still, some cases of infantile tabes have been recorded.⁷⁷

⁷⁷ Excluding the so-called family form of locomotor ataxia: 6 rather imperfectly described cases are cited by Remak (loc. cit.), and 3 additional ones related by himself. Of the latter, 2 had hereditary syphilis, and of 1 the father was both syphilitic and tabic.

In the majority of cases tabes is due to a combination of a number of the above-mentioned factors. The majority of tabic patients in the middle and wealthy classes have had syphilis, and of these, in turn, the majority have been guilty of sexual excesses or perverted sexual acts, while excesses in tobacco and of alcohol are often superadded. Among the poorer patients we find syphilis less frequently a factor, but still present, according to various estimates, in from 20 to 60 per cent. of the cases. Excesses in tobacco play a lesser, and excesses in alcohol a larger, part in the supplemental etiology than in the other class, while exposure to wet and cold and over-exertion are noted in the majority; indeed, in a fair proportion they are the only assignable causes.

DIAGNOSIS.—The recognition of advanced tabes dorsalis is one of the easiest problems of neurological differentiation. The single symptom which has given one of its names to the disease—locomotor ataxia—is so manifest in the gait that even the sufferers from the affection learn to recognize the disease in their fellow-sufferers by the peculiar walk.⁷⁸

⁷⁸ At present I have six tabic patients under treatment, who are acquainted with each other, and who have made each other's acquaintance in the singular way of addressing one another on the strength of mutual suffering at Saratoga, at the Hot Springs of Arkansas, and in New York City.

Although there are other chronic affections of the cord which manifest ataxia, such as myelitis predominating in the posterior columns, disseminated sclerosis in a similar distribution, and some partially recovered cases of acute myelitis, the gait is not exactly like that of tabes. The uncertainty may be as great, but the peculiarly stamping and throwing motions are rarely present in these affections. The clinical picture presented by the ataxic patient, aside from his gait, is equally characteristic in advanced cases. Absence of the knee-jerk and other deep reflexes, the bladder paralysis, sensory disturbance, delayed pain-conduction, trophic disturbances, and reflex iridoplegia are found in the same combination in no other chronic disorder of the cord. It is supposable that an imperfect transverse myelitis in the lumbar part of the cord might produce the reflex, ataxic, sensory, sexual, and vesical symptoms of ataxia, but the brachial symptoms found in typical tabes as well as gastric crises would be absent. The pupillary symptoms would also fail to be developed, in all probability. It is to be remembered that only fascicular cord affections can produce a clinical picture exactly like that of tabes in more than one important respect. In analyzing the individual symptoms of the early stage the more important differential features can be most practically surveyed.

The discovery of no single symptom of tabes dorsalis marks so important an epoch in its study as Westphal's observation that the knee-phenomenon is usually destroyed in it. Had this symptom not been detected, so Tuczek admits, ergotin tabes would have eluded recognition.⁷⁹ It was claimed by a majority of neurologists at first that this jerk is always abolished in tabes, but it is now recognized that there are exceptions, as is shown by cases of Hirt,⁸⁰ Westphal, and others, not to mention some well-established cases of its return during the progress of the disease.

⁷⁹ It is not to be wondered that, like most new discoveries, that of the pathological changes of the patellar reflex should have been made the basis of premature generalizations. The attempt of Shaw (Archives of Medicine) to establish a relation between disturbances of the speech-faculty and an increased knee-jerk has not met with any encouragement or confirmation, and has been rebutted by Bettencourt, Rodrigues (L'Éncephale, 1885, 2), and others.

⁸⁰ Berliner klinische Wochenschrift, 1886, 10.

The knee-phenomenon is supposed to be a constant attribute of physiological man. It is difficult to elicit it in children, and frequently impossible to obtain it in young infants. It also disappears in old age, without having any special signification, except that this occurrence seems to be in direct relation to senile involution. In 2403 boys between the ages of six and thirteen years, Pelizæus⁸¹ found it absent in one only. It is customarily elicited by having the patient while sitting in a chair throw one leg over the other; hereupon the ligamentum patellæ is struck a short, quick blow. Under physiological circumstances the leg is jerked outward involuntarily after an interval of about one-fifth of a second—one that is scarcely appreciated by the eye. But if it be found absent by this mode of examination, the case is not to be regarded as one of absence of the jerk without further ado. The patient is made to sit on a table, his legs dangling down and his body leaning back, while he clenches his fists. By this means the jerk will often be produced where it appears to be impossible to evolve it by the ordinary means. It is also well to try different parts of the ligament, and when comparing both sides to strike on the corresponding spot and in the same direction. Many subjects who appear to be irresponsive will respond very well when a point on the outer edge near the tibial insertion is percussed. The elbow reflex, which has the same signification for the upper extremity that the knee-jerk has for the lower, is elicited in the same manner.

⁸¹ Archiv für Psychiatrie, xv. p. 206.

The absence of the knee-jerk is usually regarded as a suspicious circumstance in persons of middle life; and where it can be demonstrated that it has been present years previously and subsequently disappeared, it is looked upon as of grave import. I, however, published three years ago an authentic case of disappearance of the knee-jerk in a physician now in active practice in New York City who to this day enjoys excellent health and has developed no other sign of spinal disease. The knee-jerk is also abolished in a number of conditions not belonging to the domain of strictly spinal diseases, such as diphtheria, diabetes, secondary syphilis, and severe cases of intermittent fever. Of these, diabetes alone can be possibly confounded with tabes dorsalis. The difficulty of differentiating early tabes and diabetes is enhanced by the fact that on the one hand there are often ataxic symptoms with diabetes, while on the other both glycosuria and diabetes insipidus may complicate tabes. Senator, Frerichs, Rosenstein, Leval-Piquechef, Charcot, Raymond, Demange, Féré, Bernard, and T. A. McBride all recognize the occasional presence of the ataxic gait, paræsthesia, belt sensation, and even fulgurating pains, besides the abolition of the jerk, in diabetes mellitus.⁸² In pure cases of diabetes, however, I am not aware that spinal myosis or the reflex paralytic pupil has been found.

⁸² I have now under observation a case of myelitis with predominating sclerosis of the posterior columns of five years' standing in a merchant who has been under antidiabetic treatment for eleven years.

Abolition of the knee-jerk is found in all organic diseases of the spinal cord which destroy any part of the neural arch at the upper lumbar level, where the translation of the reflex occurs, whether it be in the posterior root-zones or in the gray matter of the origin of the crural nerves. Thus, acute or chronic myelitis, disseminated sclerotic foci of this level, may cause obliteration of the reflex at any time of the disease; so may acute or chronic anterior poliomyelitis, neoplasms, and amyotrophic lateral sclerosis of the anterior cornua type if the destruction of the anterior cornua be complete enough. It is also found abolished with all diseases of the peripheral nerves—traumatic and neuritic—which produce absolute motor paralysis of such nerves.

Among the sources of error possibly incurred in examining for this important symptom the presence of rheumatism is one. There is sometimes a tetanic rigidity of the joints which prevents the reflex from becoming manifest. It is also sometimes found to be absent immediately after severe epileptic attacks, according to Moeli.⁸³

⁸³ In three examinations after severe attacks of epilepsy I found it normal.

The condition of the pupil is perhaps a more constant sign of early tabes than the loss of the knee-jerk; at least it has been found well marked in cases where the jerk had not yet disappeared. It may be regarded as a rule in neuro-pathology that wherever reflex iridoplegia is at any time accompanied by other oculo-motor disturbance, it is either of spinal origin or in exceptional cases due to disease of the pons varolii. The peculiar character of the pupillary disturbance of tabes furnishes us with a criterion for distinguishing it from one affection which in common with it exhibits loss of the knee-jerk—diphtheria. In diphtheria there is also a reflex disturbance of the pupil, but it is the reverse of that of early tabes. In the latter reaction to light is lost, but the accommodative contraction power is retained; in diphtheria accommodative contraction power is lost, but reaction to light is retained.

The bladder disturbance has already been described. It is found as a marked symptom so prominently in no other systemic affection of the cord, and in few of the non-systemic forms, of sclerosis. In none of these is it associated with absence of the patellar jerk, reflex iridoplegia, and fulminating pains, as in tabes, except there be also some motor paresis. It is the combination of any two of the important initial symptoms of tabes without paralysis or atrophy that is regarded as indicative of the disease by most authorities. Thus the swaying in closing the eyes, if associated with the Argyll-Robertson pupil, is considered as sufficient to justify the diagnosis of incipient tabes, even if the knee-jerk be present and fulminating pains and bladder trouble absent. Undoubtedly, the tabic symptoms must begin somewhere. But at what point it is justifiable to give a man the alarming information that he is tabic is a question. I have a number of neurasthenic subjects now under treatment who have had reflex iridoplegia for years; in one the knee-jerk is slowly becoming extinguished; in two it has been becoming more marked after becoming less; in all the three mentioned there is slight swaying in closing the eyes and some difficulty in expelling the last drops of urine while micturating. I do not believe that such a condition justifies a positive opinion, although the surmise that they are on the road to developing tabes may turn out correct for all these and for some of those who have merely reflex iridoplegia.

Incipient tabes cannot be readily confounded with any other chronic disease of the spinal cord. Some of the cases produced by sudden refrigeration resemble a beginning myelitis. But the absence of true paralysis seems to distinguish it from the latter. In all the cases of so-called acute locomotor ataxia of myelitic origin that I can find a record of, paralytic symptoms were marked, if not throughout the disease, at least in the initial period.

Other forms of sclerosis occasionally limited to the posterior columns imitate the symptoms of tabes. It is unusual, however, for such sclerosis to be distributed through so great an extent of the posterior columns as to produce symptoms consistent with tabes in both the upper and lower extremities. And even where this condition is complied with, the typical progress so characteristic of tabes is not adhered to. As previously stated, the progress is weakened by variations in certain symptoms. Such variations are found in other forms of sclerosis, but they are not as great, trophic disturbances not so common, and visceral crises not so violent, as a rule.

The discovery of ataxic phenomena as a symptom of peripheral neuritis has added another to the long list of pseudo-tabic affections. Indeed, Dejerine, who greatly advanced our knowledge of this affection, undertook on the strength of his discovery to place tabes among the peripheral affections complicated by secondary affection of the cord. In a large number of cases of peripheral neuritis, particularly the alcoholic form described by Fischer, the static ataxia, belt sensation, bladder trouble, and reflex iridoplegia are absent. In tabes the severe pains, if influenced by deep pressure at all, are affected favorably, but in peripheral neuritis pressure on the affected nerve-trunk greatly aggravates the trouble.

In addition, those severe forms of neuritis that lead to ataxia, abolition of deep and other reflexes, are accompanied by qualitative electrical changes and atrophic paralysis—features not found in tabes. Sometimes a disseminated neuritis will become so generalized as to cause diplopia and other evidences of ocular paralysis through the affection of the peripheral nerves, but, so far as my observations extend, not with the characteristic pupillary phenomena of tabes.

Cerebellar disease, alcoholic and hysterical neuroses, sometimes produce ataxia, and this may be associated with one or more of the other characteristic symptoms of tabes. Cerebellar ataxia is usually very different from that of tabes, as far as the locomotor element is concerned. In tabes it is the movements the patient makes which cause him to stagger; in cerebellar disease those movements made to prevent staggering are usually co-ordinated. The gait properly called cerebellar is therefore very different from that of tabes. There is, however, static ataxia in both cerebellar and posterior-column disease. In addition, the knee-jerk may be abolished in the former, heightening the resemblance: the history of the case is, however, decisive where these latter symptoms might lead to doubt. Bladder trouble in cerebellar disease is not an early feature, nor are paræsthesias and delayed pain-conduction intrinsic features, of cerebellar disease. Their presence is in favor of tabes.

Alcoholic ataxia is very rapid in its course, while tabic ataxia is exceedingly slow. In addition, the former is accompanied by atrophic paralyses as early features; if such occur in tabes, they occur late in the disease, and are not marked by degenerative electrical reactions as alcoholic ataxia is. This disorder is usually, too, accompanied by fever, which is an exceptional, and certainly never an intrinsic, feature in tabes. Discontinuing the alcoholic poison is usually followed by rapid amelioration of the ataxia. Hysterical ataxia exceptionally apes the ataxia of tabes; the presence of other hysterical phenomena, the rapid and bizarre change of the symptoms, are distinguishing features. There are cases of hysterical ataxia accompanied by concentric limitation of the field of vision.⁸⁴ The outline of the limitation is strikingly like that accompanying atrophy, but repeated examination shows a variation of a kind not found in the latter. The blind field advances in one direction to recede in another on one day, and reoccupies the latter and recedes from the former on the next.

⁸⁴ Landesberg, Journal of Nervous and Mental Diseases, vol. xiii. 2.

Ataxia after most acute diseases, such as scarlatina and typhoid, is not usually accompanied by loss of the knee-jerk, and never by reflex iridoplegia. The ataxia after diphtheria is complicated by the former, but, as already stated, the very opposite state of the pupil serves to distinguish it.

The hereditary form of tabes is frequently confounded to this day with true tabes dorsalis. The family history and age of the patient are collateral evidences of the nature of the case. In the hereditary form the sphincters, optic nerves, and the eye-muscles are not affected; in the acquired form the first and last are always involved; and this involvement occurs so early in the disease as to constitute a valuable discriminating feature. Although the locomotor ataxia is very similar in the two affections, static ataxia, the symptom manifested on closing the eyes, is not found in the hereditary form, while it is found more constantly than even the locomotor ataxia in the acquired form.

The electrical reactions in tabes are either normal or quantitatively slightly increased. This serves to distinguish it from all spinal affections accompanied by marked paralysis. In the later stages, when some atrophy results, there may be a quantitative decrease, but these are without qualitative changes. A change may occur in those exceptional cases where the anterior gray horns become involved, but we then have to deal with a true complication; and complications can be recognized only in their development and by the application of the diagnostic criteria characterizing the complicating disorder when of an independent occurrence.⁸⁵

⁸⁵ It is not impossible that many of the symptoms described as occurring in advanced tabes are due to independent focal disease. In the case of a female aged seventy years mentioned by Hirt (Berliner klinische Wochenschrift, 1885, No. 26), who developed hemiatrophy of the tongue, probably from a hemorrhage in the brain isthmus, there was no tabes, although this symptom when found with tabes is supposed to be part of the tabic symptom-group.

The TREATMENT of tabes dorsalis will be considered at the end of this article, together with that of the sclerotic processes generally. The duration and prospects of the disorder have been considered with the clinical history. In the vast majority of cases the course of the illness is progressive. A few cases have been reported, but in the only instance where an autopsy was made to test the matter it was found that the sclerosis had not been removed. It may be therefore stated that an arrest of the disease is possible, but that restitution of the nerve-elements, once destroyed, is impossible.

Spastic Spinal Paralysis.

SYNONYMS.—Primary lateral sclerosis. Tetanoid pseudo-paraplegia, (Seguin), Tabes dorsal spasmodique. This symptom-group was first recognized by the American neurologist Seguin⁸⁶ thirteen years ago; two years later Erb⁸⁷ described it under the title at the head of this section, and about the same time Charcot⁸⁸ attributed the well-marked clinical signs thus discovered on both sides of the Atlantic to a primary sclerosis of the lateral columns of the cord in that portion which is known as the crossed-pyramid tract, and whose isolated disease had been known to Türck,⁸⁹ but not clearly brought into relation with what is now regarded as one of the most remarkable and recognizable of spinal symptom-groups. Our earlier knowledge of the disease has been much confused through the discovery by Charcot⁹⁰ of the same lesion to which spastic paralysis is attributed by him, in a female who had been suffering from permanent contractures of all extremities, and which he persisted in regarding as hysterical. The only solution of the difficulty is to accept one of two alternatives—either believing that the sclerosis was in this case primary, in which case contracture cannot be regarded as hysterical, or that it was secondary to protracted disuse of the limbs, in which case it proves nothing. An additional source of confusion has been the discovery of an analogous affection, now regarded as clinically and pathologically distinct, known as amyotrophic lateral sclerosis, and of a corresponding affection of the lateral columns in a large number of cases of paretic dementia.

⁸⁶ E. C. Seguin, “Description of a Peculiar Paraplegiform Affection (tetanoid pseudo-paraplegia),” Archives of Scientific and Practical Medicine, February, 1873. Erb's statement (Ziemssen's Cyclopædia, vol. xi. 2, p. 628) that Seguin's description includes symptoms which do not properly appertain here can no longer be sustained, in view of the similar and identical symptoms which have been since attributed to the same affection and to amyotrophic lateral sclerosis by later writers. There seems to be no question that the priority of recognition of the clinical form belongs to this side of the Atlantic.

That Seguin's title was not as badly chosen as Erb implies in his first reference to it may be inferred from the fact that Strümpell, without any reference to Seguin, and evidently independently of him, uses the following language ten years later: “As also in these cases, the movements are not immaterially influenced by the ever-occurring spasms, a motor disturbance may be simulated which we feel inclined to term spastic pseudo-paralysis, or, more correctly, pseudo-paresis” (Pathologie und Therapie).

⁸⁷ “Ueber einem wenig bekannten spinalen Symptomencomplex,” Berliner klinische Wochenschrift, 1875, No. 26.

⁸⁸ “Sclérose primitive de la partie postérieure des cordons antero-lateraux,” Gazette médicale de Paris, 1874, pp. 38, 39.

⁸⁹ “Ueber primäre degeneration einzelner Rückenmarkstränge,” Sitzungsberichte der Kaiserlichen Akademie der Wissenschaften zu Wien, Mathematisch-Naturwissenschäftliche Klasse, Band xxi. Jahrgang 1856, p. 112.

⁹⁰ Gazette hébdomadaire, 1865, 7.

CLINICAL HISTORY.—Spastic paralysis manifests itself chiefly in three symptoms: first and most noticeable, a condition of rigidity of the limbs; second, an increase of all the muscular reflexes; and third, a true motor paresis. It manifests itself in the adolescent or middle period of life, usually without any noticeable cause, beginning in the lower extremities, and, if progressive, involving the muscles of the trunk and arms. The invasion of the disease is first marked by an increase in the excursiveness of the muscular phenomena, such as the knee-jerk and the ankle-clonus. But while this reflex irritability is originally only manifested when the diagnostician applies his special tests, it soon becomes so great that the most trivial influence suffices to bring about exaggerated muscular reaction. The mere tension of a tendon in walking, the weight of the limb, the slightest change in position, suffice to produce reflex muscular tension. The muscles feel firm and stiff to the touch, as if permanently contracted, and the lower limbs, as a result of the combined contraction of special muscular groups, assume a characteristic position—namely, an extension contracture of the leg on the thigh and a flexion of the foot on the leg. In advanced cases the contracture is so extreme that it is almost or actually impossible to flex the leg and to extend (dorsiflect) the feet. This is particularly noticeable when it is attempted to overcome the strained position suddenly, while gradual traction will often succeed in relaxing the contracture. The latter procedure succeeds because sudden traction of the tendons and the reflex contraction thereby provoked are avoided by it. Gowers compares this symptom to the mechanism of a clasp-knife. When the leg is slowly extended it yields to the manipulator's influence, but as soon as it reaches full extension it remains like the blade of the knife fixed by a spring.

Although some degree of muscular weakness is experienced in the beginning of the affection—often more marked in one leg than the other—it is insufficient to account for the grave and characteristic disturbance of locomotion. This is due rather to the stiffness of the limb resulting from the morbid muscular spasm. As the limbs are rigid, the steps are short; the leg not being flexed, and consequently not being lifted from the ground, the gait consists in an awkward shuffle.⁹¹ The feet are in continuous contact with the ground, and it is observed that there is a tendency to walk on tiptoe, owing to the contracture of the gastrocnemius, in this respect resembling the pes-equinus position. In some cases it has been observed that the reflex excitability was so great that the mere need of urinating brought on a sudden tonic spasm, and there have been noted others in which the very first spasmodic phenomena occurring in the history of the case appeared while the patient emptied his bladder.⁹²

⁹¹ It was Theodore Simon, I believe, who first suggested the registration of peculiarities in gait by using sand on the floor or compelling the patient to walk over large sheets of paper with black-leaded shoes. Among the varieties of gait noted in paretic dementia by him he accurately describes that of spastic paralysis (Die Gehirnerweichung der Irren, Hamburg, 1871).

⁹² Westphal, Archiv für Psychiatrie, xv. p. 224; ibid., p. 229.

When the upper extremities are involved, the same initial muscular weakness and exaggerated reflex excitability are noted, but the contracture at the elbow, unlike that at the knee, is usually in the flexed position.

If from any cause the spastic phenomena happen to be in the background temporarily, so as to admit testing the voluntary muscular power, it is always found to be grossly impaired.⁹³

⁹³ This statement is made by Westphal, but as he considers the only pure cases of pure primary lateral sclerosis to be those associated with paretic dementia, and it is in the latter form alone that there are marked exacerbations and remissions in the spastic symptoms, it probably does not apply to uncomplicated spastic paralysis.

As the disease progresses locomotion becomes impossible; the advancing rigidity of the trunk-muscles renders sitting impossible, and the patients become bedridden. But even in this advanced stage no sensory or vegetative disturbances were noted. The cutaneous reflexes sometimes appear exaggerated, but this is not an evidence of sensory hyperexcitability, but of the increased ease with which the motor response is elicited—a feature which is also illustrated by the spasm resulting from fulness of the bladder or even from the mere act of micturition. Ataxia has never been noted in pure cases, and the uncertainty in gait sometimes noted at the onset of the disease is secondary to the motor weakness and the interference with free mobility by the, as it were, frozen state of the muscles. Occasionally the paresis becomes a veritable paralysis, but this occurrence is limited to one or several muscular groups. Cases are related in which the spastic symptoms occurred on one side, involving one arm and leg for years before involving the other. It is not improbable that these were cases of some obscure cerebral affection. Other exceptional cases in which the spastic phenomena appeared first in the arms are better authenticated.

The early occurrence of ankle-clonus in this disease heralds the appearance of apparently spontaneous clonus when the toes are put on the ground, and later on of cramps of the gastrocnemius or other muscles, which produce an exacerbation of the existing stiffness. Occasionally sudden spasms occur while the patient is at rest, and which resemble the sudden shocks which healthy persons occasionally experience when about to fall asleep.

The electrical reactions show little that can be called characteristic, and there is little unanimity among observers on this point. The majority agree that there is a slight quantitative decrease of both faradic and galvanic excitability in parallelism with the degree of paresis. In the pure form of the disease there are no other symptoms than those mentioned. Should evidences of involvement of the gray substance of the cord or the cranial nerves be added, it is a certain indication that we have to do with the similar but far from identical affection, amyotrophic lateral sclerosis.

The course of the disease is extremely slow and its development insidious. It is considered incurable, and although a few cases have been described as terminating in recovery, the most recent and reliable annals fail to make mention of any cure in a well-established case of spastic paralysis. The disease is not in itself fatal, death usually occurring from intercurrent affections.

ETIOLOGY.—Our knowledge of the causes of this disease is practically nil. It has been, like tabes dorsalis, attributed to a family tendency. Excessive sexual indulgence, over-exertion, and syphilis have been recorded as possible causes in the few cases in which an etiological assignment could be attempted. Tuczek surmises that the spastic phenomena of lathyrism, a constitutional disease analogous to pellagra and ergotism which is observed in those who live on bread prepared from a legumen grown in Italy (lathyrus bean), and which manifests itself in spastic symptoms, may be due to an affection of the pyramid tract, just as tabes ergotica is due to an affection of the posterior columns. One case of spastic paralysis of a severe nature, associated with scanning speech, in consequence of a lightning-stroke, is reported by Demme.⁹⁴ I have been able to assign a cause in but two cases of spastic paralysis. Both were in Quakers; in both there had been a history of almost incredible sexual excesses. The disease in both involved the muscles of the jaw and face. An autopsy in the one case revealed no lesion whatever.⁹⁵

⁹⁴ “Bericht über die Thätigkeit des Jennerischen Kinderspitals,” Wiener medizinischer Blätter, 1884, No. 23.

⁹⁵ The contracture in the lower extremities, differing from the rule, was a flexion contracture.

MORBID ANATOMY AND PHYSIOLOGY.—Although Charcot's announcement that spastic paralysis is due to sclerosis of the crossed-pyramid tract was made with great positiveness, the more careful authorities have not committed themselves to his view without reservation. Their reserved position is the result of some observations which certainly show that there is no constancy between the distribution of the lesion and the distribution of the spastic paralysis;⁹⁶ while, on the other hand, characteristic spastic symptoms have been noted with purely cerebral lesions.⁹⁷ Morgan and Dreschfeld⁹⁸ publish cases in which the lesion was stated to be characteristic, but as the cell-groups in the anterior horn were found by them to have been more or less affected, it is evident they had cases of amyotrophic lateral sclerosis to deal with. In view of similar revelations in a large number of the cases that had been considered as spastic paralyses during life, and in which similar findings were found after death, Westphal,⁹⁹ one of the most critical students of the subject, concludes that thus far an anatomical basis has not been demonstrated with any constancy for the cases of spastic paralysis uncomplicated with paretic dementia. With this disease a sclerosis of the lateral column, apparently independent of the cerebral affection, is often found. It has no continuity, as a rule, with the cerebral lesion, and it may be limited to special districts of the cord. It is not usually intense enough to produce material destruction of the tract itself, and for this reason, probably, we do not find any other symptoms than a paretic weakness and an increase of the patellar and other muscular phenomena developed in the majority of paretics. In some, however, the characteristic spastic gait and muscular rigidity do develop. Westphal conjectures that if paretic dements lived as long as the sufferers from uncomplicated spastic paralysis, they would ultimately show the typical symptoms.¹⁰⁰ Numerous observations, however, show that the presence and intensity of the spastic symptoms in paretic dementia are not related to the presence and intensity of lateral-column lesion. Thus, Zacher¹⁰¹ failed to find such lesion in a case where the spastic symptoms had been well marked. It must be remembered, in drawing conclusions regarding the pathogeny of simple spastic paralysis from the lateral-cord affection and associated symptoms of paretic dementia, that the possibility of the lesion of the pyramid tract in this affection being secondary to disuse¹⁰² cannot be excluded. On the other hand, the symptoms of most paretic dements presenting lateral-column lesion differ in some respects from those of a pure spastic paralytic. There is a precedent clumsiness and helplessness of movement; the patient stumbles and trips more than is the case with the pure spastic gait; he wavers after suddenly turning around, and there is considerable tremor with intended movement. There is also more exacerbation and remission of these symptoms than is the case with true spastic paralysis, and it is observed that the exacerbations usually follow apoplectiform and epileptiform attacks, thus showing that the cerebral condition, after all, may be the determining factor.

⁹⁶ Fischer and Schultze (Archiv für Psychiatrie, xi. 3) report an impure case in which, with exquisite spastic symptoms in the neck and arms, the degeneration of the pyramid tract was limited to the dorsal part of the cord.

⁹⁷ Schulz (Deutsches Archiv für klinische Medizin, Band xxiii.) and Strümpell (Archiv für Psychiatrie, x.).

⁹⁸ Journal of Anatomy and Physiology, xv. p. 510.

⁹⁹ Archiv für Psychiatrie, xv. p. 246.

¹⁰⁰ Another feature which antagonizes the development of spastic phenomena in paretic dementia is the lesion of the posterior columns which often ensues. In proportion as this is developed it neutralizes the exaggerated knee-jerk, stiffness, and spastic gait.

¹⁰¹ Archiv für Psychiatrie, xiii. p. 155.

¹⁰² It has been claimed against this view that if this were so the degeneration of the pyramid tract should be accompanied by degeneration of the cells in the anterior horn. This claim assumes that the cells and the pyramid tract are directly continuous, but the most modern researches, those of Von Monakow, confirming an older observation of Homén's, show that a system of small cells in the lateral reticular processes is interpolated; which I can confirm. It is certainly compatible with an atrophy from disuse of the voluntary tract that the cells themselves, presiding over reflex and nutritive functions not necessarily disturbed in paretic dementia, should remain nearly intact.

There is another respect in which the two conditions differ. Spastic paralysis is usually an ascending affection, the lower extremities being involved first, the trunk next, and the upper extremities last. But in paretic dementia the spastic phenomena develop in both upper and lower extremities simultaneously, and there are universal tremors, probably of irritative origin. The lower extremities are not commonly in the extension contracture of spastic paralysis, but in the same flexed position as the arms, the adductors usually preceding the flexors in becoming rigid. If it be added to this that the lateral-column lesion in paretic dementia appears to answer all the requirements which could be made of the lesion on theoretical grounds were the case one of pure spastic paralysis—that is, that its area decreases upward—the inconsistency of the observed anatomical and clinical facts becomes strongly evident. Thus far, the attributing of spastic paralysis to a primary lesion of the pyramid tract rests in a few contested cases, on a number of doubtful analogies, and on the undoubted fact that sclerosis of this tract in the event of a myelitis is followed by pronounced spastic symptoms in all those muscles which derive their voluntary innervation from the part of the tract which lies below the level of the lesion.

The situation of this tract, which was not discovered by Türck and Flechsig, as is usually supposed, but accurately known to Burdach¹⁰³ in 1819, may be roughly stated as follows: It lies in the dorsal half of the lateral column, making up the bulk and core of this part of the column. It is separated from the pia mater by the direct cerebellar tract, and from the posterior gray horn by a narrow zone of fibres differentiated by Lissauer (see Tabes). It is connected with the lateral reticular processes, and in its cephalo-caudal course becomes gradually attenuated, giving off its fibres to these processes, thus to be exhausted in the lower part of the lumbar enlargement of the cord, where it approaches, if it does not actually reach, the surface. The fibres controlling the voluntary motions of the lower limbs, and which have a longer course to run before they reach the brain than those which mediate the voluntary control of the arms, are situated nearest the lateral boundary of the cord. Where the spastic phenomena are mainly marked in the lower limbs the sclerotic process has been found most marked in the corresponding area.

¹⁰³ Vom Bau und Leben des Gehirns. This gifted author says that the crossed-pyramid tract lies in the lateral column of the cord, behind a line corresponding to the attachment of the ligamenta denticulata and removed from the surface.

The progress of this affection has not been materially modified in any case by treatment. The same measures employed in sclerotic processes generally, particularly galvanism and warm baths, are recommended. It is difficult to understand what good effect ergotin, which is mentioned by a number of the German writers, can have in a disease of this nature.

Amyotrophic Lateral Sclerosis.

Amyotrophic lateral sclerosis, so named by Charcot¹⁰⁴ and Joffroy, who first described it, consists in a disease affecting both the conducting tracts and nuclear centres of the motor system of the spinal cord and medulla oblongata, manifesting itself in a combination of atrophic and irritative phenomena on the part of the muscles. The relations between the symptoms and lesions of this disease rival in constancy and preciseness those noted in typical tabes dorsalis. As the variations in the mode of invasion and distribution of the lesion account for the widely-differing clinical types of the disease, and the advanced state of our anatomical and physiological knowledge of the cord enables us to interpret the reason of this difference, we shall invert the usual order and discuss the morbid anatomy first.

¹⁰⁴ In 1869 and 1874 (Leçons sur les Maladies de la Système nerveux) Charcot termed this, and one other form of disease associated with muscular atrophy, amyotrophic, to distinguish them from the myopathic forms. He considers amyotrophic lateral sclerosis as deuteropathic, the nuclear atrophy being secondary to the lesion of the white substance, and the progressive muscular atrophy of the type described by Duchenne and Aran as a protopathic form of the amyotrophies. Among the true myopathies he enumerates pseudo-hypertrophic paralysis, Erb's juvenile form, Duchenne's infantile form, certain mixed forms, and, without justification, Leyden's hereditary forms (report by Marie et Guivron, Progrès médicale, 1885, No. 10).

MORBID ANATOMY.—In advanced cases of amyotrophic lateral sclerosis there is found marked sclerotic degeneration of both the crossed and the uncrossed pyramid tracts; atrophy of the cells of the anterior horns; atrophy of some of the nuclei of the motor and mixed cranial nerve, particularly the hypoglossal and spinal accessory; atrophy of the anterior roots of the spinal and the roots of certain motor cranial nerves; and, finally, atrophy of the voluntary muscles. The greater part of the tract through which the voluntary impulse travels after leaving the voluntary motor-fields of the cortex is therefore continuously involved; and it would seem that there are cases (Kahler-Pick's) where the entire motor system is affected, the morbid process demarcating the course taken by the motor impulse through the cerebro-spinal fibre-labyrinth from the cortical motor-field down to the muscles.

The morbid process in the muscles consists of a narrowing of the fibres, which subsequently lose their transverse striation and undergo a granular disintegration. Sometimes a muscle disappears entirely; usually the connective-tissue elements, including the interstitial cellular and adipose tissue, undergo proliferation, so as to mask the wasting of the muscles to some extent.

The morbid process in the nervous system is also a simple degenerative process. The nerve-fibres and cells atrophy first, and the connective-tissue proliferation which marks the sclerotic change of the diseased area is a secondary process. There is still considerable dispute among authorities as to which segment of the motor-conduits the degeneration begins in. But from the great difference found in the individual cases which have become the subject of patho-anatomical studies there can be little doubt that there is no uniformity in this respect. In some cases the lesion is far advanced in the lateral columns, while the anterior horn is but slightly involved; in others the reverse is found. Sometimes the nuclei of the motor cranial nerves are the chief foci of disease; at others they are the least affected parts of the motor apparatus. As we shall see, there are differences in the clinical picture corresponding to the variations of the anatomical findings.

CLINICAL HISTORY.—In typical cases the first symptom is a tired feeling in one arm or leg, usually the former; in dextral persons the right arm, the one which is subject to the severest strain, is most frequently the first to be affected. With the increase in this tired feeling there develops actual loss of power; the muscles become wasted, and the other arm becomes involved. Often it is observed that the right leg suffers with the corresponding arm, but as a rule the lower extremities do not become involved to any marked degree within the first six months of the illness. It is then noted that a gait not unlike that of spastic paralysis is noted, but with more loss of motor power and less stiffness. There is, however, this noteworthy difference between the affection of the lower and that of the upper extremities: that atrophy and loss of power are more marked in the latter, and spastic phenomena in the former. The knee-jerk and other deep reflexes are greatly increased, and ankle-clonus is usually very well marked. As with spastic paralysis, there are no visceral or sensory disturbances. Unlike that affection, there are qualitative changes in the electrical reaction of the muscles¹⁰⁵ in amyotrophic lateral sclerosis. The degeneration reaction is found in the atrophied divisions, and particularly in such groups as those of the thenar and hypothenar eminence, which undergo complete atrophy at a comparatively early period of the disease.

¹⁰⁵ Moeli, Strümpell, Pick, and Mierzejewski describe cases in which only quantitative changes were found. They were such in which spastic phenomena preponderated at the time of the examination.

Soon after the spastic and atrophic involvements of the lower extremities, symptoms indicating the involvement of the cranial nerve-nuclei are developed, usually after the disease has lasted a year or so. Deglutition becomes difficult and speech indistinct, the general picture of a glosso-labio-laryngeal paralysis being imitated. The patient cannot pucker his lips, his lingual muscles undergo atrophy, and fibrillary and fascicular twitches are noted in the tongue and lips. But just as the atrophic affection of the muscles of the arms and legs differs from that of progressive muscular atrophy in the fact that the deep reflexes are exaggerated with amyotrophic sclerosis, so in the bulbar symptoms of the latter it is found, unlike the typical form of bulbar paralysis, that the jaw reflex is increased.

The duration of the disease may be stated at about three years, death usually occurring in consequence of the involvement of the cranial nerves. There are cases recorded where the disease was almost simultaneously developed in all four extremities and the tongue, reaching a high degree within a year (Mierzejewski). It is generally agreed that the reason contractures do not develop in typical cases of this kind, although the lateral column is sclerosed and spastic phenomena occur early in the disease, is the destruction of the cell-groups in the anterior horn. The reflex arch through which a reflex contracture would be mediated is broken, or rather weakened, in that part of its course which passes through these cells, and therefore a contracture is as efficiently antagonized as it would be if the posterior roots were divided. Still, in some cases a frozen attitude of the lower extremities is very well marked (Vierordt, Zacher). To reconcile these conflicting observations it has been suggested that it may be regarded as a question of speed between the progress of the pyramid-tract and the anterior-horn lesions. If the former be much in advance of the latter, spastic phenomena will preponderate and contractures be possible, to disappear with the subsequent anterior-horn lesion. But if the latter precede and preponderate, the spastic phenomena will be in the background and contractures impossible. Indeed, Zacher¹⁰⁶ suggests that there may be an ascending form in which the lesion of the pyramid tract is secondary to the nuclear atrophy, corresponding to the typical class of cases on which Charcot based his first description of the disease, and a descending form in which the pyramid tract is first affected and the nuclear cell-groups follow. Vierordt¹⁰⁷ and Kahler¹⁰⁸ express similar opinions. The latter goes so far as to suggest that progressive muscular atrophy, progressive glosso-labio-laryngeal paralysis, and amyotrophic lateral sclerosis are really due to one and the same kind of degenerative process, merely differing in location. There is certainly, as he claims, a remarkably complete chain of cases, beginning with such (1) in which spastic paralysis preponderates, passing thence to (2) those in which some muscular atrophy preponderates, then (3) those in which muscular atrophy is in the foreground and the spastic phenomena are slight, and ending with (4) the pure atrophies. A similar transition may be established on the regional principle between pure glosso-labio-laryngeal paralysis and amyotrophic lateral sclerosis, for there are cases of this affection in which the oblongata symptoms preponderate throughout, and the focus of the disease is formed there, just enough lesion being demonstrable in the pyramid tract and the spinal gray matter to prove the family relationship of what clinically appears as a spastic bulbar paralysis.¹⁰⁹

¹⁰⁶ Archiv für Psychiatrie, xv. p. 416.

¹⁰⁷ Ibid., xiv. p. 397.

¹⁰⁸ Zeitschrift für Heilkunde, 1884, p. 109.

¹⁰⁹ Such a case is described by Freund in Deutsches Archiv für klinische Medizin, xxxvii. p. 405.

PROGNOSIS.—As far as the typical cases of this disease have been studied, a fatal termination seems to be invariable. Seeligmüller reports a few cases in which the progress appeared to become arrested, but it is not clear that these were not in reality cases of some juvenile form of muscular atrophy. Not only is the affection in adults fatal, but it is so in a short period of time as compared with other spinal disorders, and particularly with the related disorder spastic paralysis. Few patients survive the third year of their illness; a number do not live to that length.

The Combined Forms of Sclerosis.

A number of cases of chronic sclerotic disease of the cord have been discovered and analyzed during the past decade, which, while they show the regularity of distribution noted in posterior and lateral scleroses, differ from them in involving at once more than one column of the spinal cord. Usually, it is the posterior column and the posterior part of the lateral column which are affected. The symptoms constitute a combination of those of tabes dorsalis and of spastic paralysis. But this combination does not represent a mere addition of symptoms; where the tendency of the two diseases conflicts, they neutralize each other. Thus the tendency of lateral sclerosis uncomplicated by posterior sclerosis is to increase the patellar jerk; when posterior sclerosis complicates it, the jerk is annihilated. The degeneration of the lateral column and the ensuing motor paresis in like manner neutralize the ataxic character of the gait by limiting its excursiveness.

The upper extremities are usually involved equally with the lower. In the cases of Kahler-Pick considerable atrophy of the muscles developed; in those of Prévost and Westphal this was not very noticeable. In a few cases, where the posterior sclerosis did not involve the lumbar part of the cord, spastic symptoms were noted in the lower extremity. In the only case of combined sclerosis now under my observation this peculiarity, noticed by Prévost, is well marked. In one of Westphal's cases there was evident mimic ataxia. The few cases of this affection observed show so many variations that it would be at present premature to attempt sketching a common clinical type. The majority of the subjects were affected between the twenty-fifth and forty-fifth years.

ETIOLOGY.—Little is known of the causes of this disease. Usually beginning insidiously, no special mode of origin can be determined. Surface chilling has been assigned in a case by Erlitzky and Rybalkin, and others are reported to have begun during pregnancy. One of Westphal's cases developed in a lithographer who had been subject to epileptoid fits.

DIAGNOSIS.—As yet we have no reliable criteria for distinguishing between a combined sclerosis and certain forms of diffused sclerosis during life. Ballet and Minor¹¹⁰ found such a sclerosis diffusely involving the posterior and lateral columns of the cord in a case where they were justified from the symptoms in expecting a combined fascicular sclerosis of these columns, and after a careful study of all similar cases collated by them in consequence of this experience, they came to the conclusion that a number of affections of different origin, but eventually involving both columns, may impose on the observer as combined fascicular sclerosis during life. Diffuse meningo-myelitis is one of these affections, and is far from uncommon, while true system or combined sclerosis is apparently a very rare disease.

¹¹⁰ Archives de Névrologie, vii. p. 44.

The Family Form of Tabes Dorsalis.

SYNONYMS.—Friedreich's disease, the Family form of locomotor ataxia, Hereditary ataxia, Hereditary tabes.

Friedreich discovered a peculiar form of co-ordinating disturbance in a number of children of the same family, which he brought into relation with a lesion of the posterior columns, and which has been since found by him and by subsequent observers to occur in other cases, always affecting several members of the same family, as in the first case observed by him. The clinical and pathological features, though resembling those of the tabes dorsalis of adults in many respects, are distinct in others, and for this reason it is generally assigned a separate place in classification.

ETIOLOGY.—The disorder is usually manifested in juvenile life, the age of the affected subjects varying from the seventh to the twenty-fifth year. The male sex preponderates in the statistics of the affection. Some neuropathic vice can always be found in the patient's immediate ancestry, and the limitation of the disease to families burdened by such a diathesis is exemplified in the fact that the ninety individual cases thus far accurately studied occurred in thirty-six families.¹¹¹ The disease type of the ancestors of the patients is usually different from that of the latter. Alcoholism in the father is one of the commonest forms, but convulsions, hysteria, and insanity are also frequent features of the family history. In a few cases tabes dorsalis, properly so called, was present in the father. In others there was consanguinity of the father and mother. In Musso's group the parents had been brother and sister, and their mother had been a melancholic dement. Three other grandchildren and six grandchildren by the incestuous marriage developed the family form of tabes. In this family the frequent experience of hereditary transmission was verified—that the neurotic taint skipped the intermediate generations.

¹¹¹ Raffaele Vizzioli, Giornale di Neuropatologia, 1885.

CLINICAL HISTORY.—Usually the first symptom is ataxia of the lower extremities; occasionally this is preceded by severe frontal headache or by vague rheumatoid pains. The inco-ordination is very similar to that of true tabes dorsalis, but swaying on closing the eyes is not noticed early in the disease, as in the latter affection. The arms soon become involved in the ataxia, but cutaneous sensibility and the muscular sense remain either intact or nearly so—a fact utilized with some success by Erb in polemicizing against the theory of Leyden that the ataxia of tabes is due to imperfect sensation. Later in the disease, usually after a few years, a peculiar speech-disturbance is noticed, which resembles the scanning of disseminated sclerosis. It depends on ataxia of the tongue and lips. This is usually associated with nystagmus. About this time the patient develops a different set of motor symptoms from those characterizing the onset of the disease; contractures, paralysis, and atrophy are found in the affected extremities; sometimes the patients cannot ascend a stair, owing to their inability to lift the feet high enough. Pes equino-varus, deformity of other joints and of the vertebral column, have been observed¹¹² to result from the associated effects of paralysis and contracture. At this stage some sensory disturbance may be developed, formication having been observed toward the close of the history in a number of cases. But the distribution of this disturbance is usually different from that of tabes dorsalis, being more intense in the trunk than in the extremities or evenly marked in the entire periphery.

¹¹² H. E. Smith, Boston Medical and Surgical Journal, 1885, vol. cxiii. p. 361.

COURSE AND PROGNOSIS.—The progress of this disease is slow. It has not yet been known to be arrested by any therapeutical procedure. Death rarely occurs directly from the disease by exhaustion; more commonly life is cut short by some intercurrent affection. Unless this occurs the patients may survive the commencement of the illness from eight to forty and more years.

MORBID ANATOMY.—The sclerosis which is found to be the constant lesion underlying this disease corresponds in every character to a combined sclerosis of the pyramid tracts and the posterior columns. Usually, the crossed-pyramid tract is degenerated in its spinal course, and the uncrossed in the cervical and dorsal part, which, in many subjects at least, is its whole extent. The cerebral part of the pyramid tract is not affected. The nerve-fibres found normally in the gray substance are materially reduced, probably in dependence upon the atrophy of the great nerve-tracts.

The lesion of the posterior columns resembles that of true tabes very closely, particularly in the lumbar part of the cord. It is, however, not probable that it commences in precisely the same distribution, and if cases dying early in the disease be autopsied it will be interesting to see whether the initial sclerosis occupies identical fields—a contingency which is unlikely, owing to the profound difference in the initial symptoms of true tabes and the family form. It is claimed by Schultze that in addition to the pyramid and posterior tracts the cerebellar tract—or, rather, a large part of the periphery of the lateral column—may be sclerosed in this disease. In this way, since the direct pyramid tract in the anterior, the greater part of the border of the lateral, and the entire posterior column are degenerated, the sclerosis resembles a marginal ring¹¹³ in shape.

¹¹³ Archiv für Psychiatrie, xiv. p. 384.

Anatomically, the sclerosis of the family form of tabes resembles that form of combined sclerosis in which the lateral and posterior columns are together affected. It is probably due to a defective development of these tracts, rendering them liable to premature decrepitude or increasing their vulnerability. The latter alternative is exemplified in those cases where some acute disease of childhood, such as scarlatina or measles, acted as an exciting cause.

DIAGNOSIS.—There are two affections some of whose leading symptoms are so closely imitated by those of this disease that they may be confounded with it on first sight. These are tabes dorsalis—of which the family form is still regarded a variety, as the name indicates—and disseminated sclerosis. In the gait the former, in the nystagmus and scanning speech the latter, disorder is approximated. The distinction from true tabes has already been dilated on. (See Tabes.) The fact that relatives—usually the sisters and brothers—of the patient are affected in the same way in their youth speaks in favor of the family form. The deep reflexes are not abolished early, as in tabes, nor are anæsthesias or paræsthesias early symptoms, as in the latter. The speech-disturbance and nystagmus, which in most cases develop later in the family form, serve to distinguish it from true tabes in the advanced stage. It is at this period that the disease may resemble a disseminated sclerosis. The hereditary or family character does not aid us in making a discrimination here, as there is also a family form of the latter disease. But the absence of intention tremor, which we would assume to be present in a case of disseminated sclerosis of the cerebral type, and of optic-nerve atrophy serves to distinguish the two. Musso claims that the speech-disturbance is also different in character. There certainly is more lingual ataxia in the family form of tabes, and less of typical scanning, but I am doubtful about our ability to differentiate these characters in all cases. The following table includes the main points of difference, clinically considered, between the acquired and the family form of tabes:

	Tabes Dorsalis.	The Family Form.
Prodromata.	Marked and constant.	Absent or slight.
Static ataxia (Romberg symptom).	Early and constant.	Absent.
Involvement of upper extremities.	Usually late.	Early.
Ataxia of tongue, eyes, and trunk-muscles.	Absent or unnoticeable.	Always developed.
Paresis.	Rare.	Characteristic.
Anæsthesia.	Present in some form.	Absent or slight.
Paræsthesia.	Constant.	Rare.
Sexual desire.	Becomes extinguished.	Remains unaffected.
Deep reflexes.	Abolition usually initial.	Abolition in course of disease.114
Sphincters.	Involvement is characteristic and early.	Involvement late, if at all.

¹¹⁴ There are conflicting observations on this point.

Disseminated Sclerosis.

SYNONYMS.—Multiple cerebro-spinal sclerosis (also spinal and cerebral form), Insular cerebro-spinal sclerosis, Focal sclerosis, Multilocular sclerosis; Herd-sklerose (Ger.); Sclerose en plaques disseminées, Sclerose en plaques generalisées (French).

The occurrence of disseminated patches of gray degeneration in the nervous axis was observed by Cruveilhier and Türck, but they regarded the affection rather from the anatomical than the clinical standpoint, and it was left for Frerichs to recognize its important position among the chronic affections of the brain and spinal cord. The earlier German investigators who followed him were cautious in generalization, and it was not until Vulpian, Charcot, and their followers announced the discovery of infallible diagnostic criteria that disseminated sclerosis received that attention at the hands of the profession which it merits. But the more thorough researches made during the last two decades have shown that this announcement was premature. The best authorities recognize the existence of a large number of cases in which the supposed pathognomonic signs of disseminated sclerosis are absent, notwithstanding the existence of characteristic lesions, and thus the more cautious earlier investigators are justified in the reserve they had maintained.

It is in perfect harmony with the irregular location of the disease and the lack of any constant rule governing the distribution of the sclerotic foci that there is no constant clinical picture by which its existence can be accurately determined in all cases. The diagnosis of tabes dorsalis, of spastic paralysis, of amyotrophic lateral sclerosis, and of transverse myelitis rests on exact and constant signs, but that of disseminated sclerosis does not. The dictum of Charcot, that there is always intention tremor and nystagmus in disseminated sclerosis, has long been overthrown. Well-determined cases are on record by De Fleury and Westphal, and a number have been observed by myself, where there was no tremor or no increased tremor with intended movement, and no nystagmus, nor any other of the pathognomonic symptoms so considered by Charcot and his followers.

The morbid process of disseminated sclerosis consists in the development of patches of sclerosed tissue, scattered apparently without any regularity or rule through the brain and spinal cord. They are the results of insidious inflammatory changes. The symptoms marking their presence may include nearly every known focal and general symptom studied by neurologists, varying with the number, size, and distribution of the foci. Usually there is some disturbance of motility, both ataxic and paretic; in the majority there is tremor, which in a large proportion of cases is of a distinctive character, and disturbance of the functions of the cranial nerves, amblyopia, color-blindness, mental enfeeblement; and, above all, apoplectiform seizures are frequent.

Some writers discriminate between cases in which the lesions are limited to, or most intense in, the spinal cord, and those in which the brain is chiefly or exclusively involved, and hence they speak of a spinal, a cerebral, and a cerebro-spinal form. This discrimination is not sufficiently supported by clinical evidence to be of any practical value. Each case is to be studied by itself during life and after death, and to be regarded as one of a series in which the lesion may be concentrated in any one segment of the cerebro-spinal axis. It seems that when the sclerotic foci are limited to or chiefly located in the spinal cord, the clinical signs are less pronounced than where the brain is seriously involved; those cases in which the symptoms are latent, or so vague that they cannot be distinguished from spinal irritation or spinal exhaustion, have been found to be of the spinal type. The cases of this character thus far observed are not sufficiently numerous to justify the creation of special subdivisions.¹¹⁵

¹¹⁵ According as the formation of the sclerotic foci preponderates in a given segment of the nervous axis, the early signs of the disease may consist in disturbances of the cerebral or the spinal functions, and we may speak accordingly of a cerebral or spinal invasion type. But the principle of classification adopted by several recent writers, which would rank the spinal type among the spinal diseases, the cerebral type among the cerebral diseases, and which is compelled to erect a third category for the reception of the cerebro-spinal type under the name of cerebro-spinal diseases, is a bad one. Modern pathology recognizes the existence of affections which involve whole fibre-systems, which are intracerebral in one and intraspinal in other parts of their course, such as tabes and amyotrophic sclerosis, which would therefore have to rank among the cerebro-spinal, and not among the spinal affections, with which the authors referred to classify them.

CLINICAL HISTORY.—Prodromal.—Disseminated sclerosis is usually inaugurated by a long initial period in which the symptoms are not characteristic, and in which, unless there be decisive pupillary or optic-nerve symptoms present, the nature of the disease is not recognized. The patients feel weak and tired; walking is difficult, and an element of unsteadiness suggests the development of a tabic disorder. In other cases ankle-clonus is found and tremor of the foot on extension (dorsiflexion); it is discovered that the unsteadiness is due to weakness or to rigidity of the muscles, and thus the impression of a developing spastic paralysis may be created. But symptoms on the part of the cranial nerves soon show that the case is one of disseminated sclerosis. Sometimes a marked belt sensation is developed, and other forms of paræsthesia are not uncommon; nay, the symptoms of spastic paralysis and tabes dorsalis may be mingled. Diplopia of the same transitory character as in tabes usually accompanies the gradually-developing speech trouble. The reflex and mechanical excitability of the muscles is increased in all cases where the lateral column is extensively involved and the gray substance of the cord is—as it usually is in the main—intact. In some cases a slight tap on the knee when held in the position required to demonstrate the knee-jerk produces oscillatory movements of the limb; as the patient endeavors to suppress these they become more violent, extend to the trunk and head, and may eventually involve the opposite side. In those cases which show the cerebral-invasion type headache, vertigo, and speech disturbance, temporary darkening of the visual field, and loss of memory are the earliest symptoms directing attention to the existence of serious disease.

Whether the spinal or the cerebral symptoms preponderate, they continue increasing slowly and with temporary variations, which are particularly marked in the cerebral-invasion type. As a rule, the sensory disturbances are not pronounced at this time, but later, after the initial symptoms have existed for a few years, they become intense, and often extremely distressing. Those most complained of by the patient are neuralgic, lancinating, and other pains. The lancinating pains are, as a rule, not as severe as those of tabes dorsalis, but they are apt to be associated with a dull heavy pain which is located in a whole extremity, referred to the deep structures, and very persistent. This diffuse pain sometimes occupies all of the lower half of the body. As in tabes, the pain may be regarded the forerunner of anæsthesia, which rarely, however, reaches a high degree or an extensive distribution. Its distribution, like that of the other peripheral symptoms of disseminated sclerosis, is commonly irregular. Like the motor disturbance, which at this period consists in a combination of paretic and spastic—occasionally of ataxic—symptoms, it is most marked in the lower extremities.

In the majority of cases there is a peculiar tremor, which usually presents the character to which Charcot directed attention—namely, that it increases when the patient attempts to carry out a voluntary movement, and disappears, or at least diminishes, when the muscles of the part in question are at rest. This is the important symptom known as the tremor on intended movement or intention tremor. One of the time-honored means of testing it is to order the patient to take a glass of water and pass it to his mouth. While he reaches out for it some oscillatory unsteadiness is observed, but on grasping, this is increased, and on raising the glass the oscillations increase till he spills the water; if he succeeds in carrying it to his mouth, there is a clattering against the teeth, and but for the steadying aid of his mouth he would throw it aside by the violence of the disturbing movements. In incipient cases this intention tremor is best shown with delicate movements, and the more distinctly the more slowly they are performed. It has been suggested that the peculiar character of the lesion of disseminated sclerosis has some relation to the intention tremor. It is a remarkable feature of the morbid process that it leaves the axis-cylinder comparatively intact, beyond any other form of myelitis or encephalitis. The myelin, however, is destroyed, and the consequence is that the naked axis-cylinders lie in a newly-formed connective tissue, which has not the same faculty the myelin has of isolating the nervous impulses conducted through the axis-cylinders. The result is, that when a nervous impulse, such as a voluntary movement, travels through a sclerotic focus, it may become deflected to neighboring fibres going to another muscle or muscular bundle than the one intended to be innervated. An unintended motion results; the patient makes a stronger effort, intended for the right channel, but again it slips off, to use a coarse simile, and thus a number of erroneous messages are transmitted, and an equal number of disturbing motions respond to these messages.

Whether this histological explanation be correct or not, the tremor is probably due to the lesion of the peduncular tracts of the brain. At least, this is rendered plausible for the tremor on intended movement, which indicates an interference with the transmission of voluntary impulses. Whether, as Pasternatzky¹¹⁶ claims, the extreme muscular oscillation seen in advanced cases is due to irritation of the cortical motor fields, it is impossible to decide. No strong evidence can be adduced in favor of his view. A few cases have been described (Schüle, Jolly, and Greiff); and, in my opinion, such are far more numerous than is usually supposed, where the tremor did not have the so-called characteristic feature of ceasing in conditions of rest, claimed by Charcot, but continued as in paralysis agitans.¹¹⁷ A collection of cases by Erb, Ordenstein, and Greiff shows clearly that with a typical dissemination of sclerotic foci in the cord the tremor on intended movement may be entirely absent, while no case is known where the crus and pons were involved to a similar extent in which it was absent. So it seems that a cerebral lesion is necessary to produce this symptom in its characteristic form.

¹¹⁶ Jahrbücher für Psychiatrie, iii. 3, 1882.

¹¹⁷ For several years I had been puzzled by the fact that Charcot's formula failed to correspond to the clinical picture in the majority of cases, and I registered such cases as incipient multiple sclerosis or as a connecting group between paralysis agitans and that disease.

In advanced cases of disseminated sclerosis the intention tremor becomes generalized; previously noticed, perhaps, only in one arm, it now affects all the limbs and the muscles which maintain the trunk and head in static equilibrium. The result is, that even when the patient is at rest sitting in a chair, his body, and particularly his head, are agitated by a violent and coarse tremor, which is increased on rising and walking, as well as on attempting to use the hands. Delicate mechanical occupations become impossible, and the handwriting shows a characteristic change, the forward strokes of the letters and the curvilinear back strokes, as well as the dots and crosses, registering the tremor of the hand in their peculiar irregularity.

The speech is usually rough and broken, and sometimes enunciation is impeded in a peculiar way, the patient appearing to scan his words. Krause¹¹⁸ has found relaxation of the vocal cords in a remarkable degree to underlie the change in phonation. The scanning of speech appears to be due to impeded innervation of the lips and tongue. When the patient is told to protrude his tongue, he does so either in spasmodic instalments of movement or with a sudden jerk after delay. The same delay and apparent halting are noticed in the mimic expressions that are observed in speech. The features sometimes express an emotion opposite to the one experienced by the patient.¹¹⁹

¹¹⁸ Neurologisches Centralblatt, 1885.

¹¹⁹ This symptom is found where there are other reasons for suspecting the existence of large foci in the pons. I have observed it in one case of tumor of this region, and one of a focal disease of undetermined anatomical nature in the same location, in a remarkable form. In the former case the patient not only exhibited the facial contortions of hearty laughter when she felt as if about to break out in tears, and broke out in tears when she felt amused, with perverse regularity, but both emotional manifestations occurred simultaneously. The other case is still under observation. There was complete anarthria in the first, and nearly complete anarthria in the second case—a fact not unrelated to the inferred site of the lesion, and which may be associated with the fact that where the perverse mimic expression occurs in disseminated sclerosis the speech-disturbance often has an anarthric character.

Whether diplopia occur as an early symptom or not, nystagmic oscillation of the eyeballs is commonly found in the developed affection. This nystagmus is usually universal, noted in associated movements in every direction, and aggravated by excitement, by constrained positions, and by any act of innervation of the eye-muscles. It may be looked upon as an intention tremor of the latter, and attributed to sclerotic foci in the cerebral axis, particularly in the tegmental part of the pons varolii.

The deep reflexes are in some cases but slightly affected. Where spastic phenomena preponderate, they are exaggerated, and where the posterior root-zones are involved in the lesion, they may be, as in tabes dorsalis, diminished or absent. The nutrition of the muscles is not impaired in the early stages, and indeed most functions which depend for their proper performance on the intact condition of the gray substance, such as the power of retaining the urine, micturition, and the functions of the rectum, are properly performed at this period. The cutaneous reflexes are not markedly abnormal in the majority of cases. They sometimes become diminished in the last stages.

In cases regarded as disseminated scleroses and similar disorders approximating the combined form of sclerosis, Westphal¹²⁰ noticed a paradoxical muscular phenomenon which is the reverse in action of the tendon reflexes. It is best observed in the tibialis anticus: if the foot be extended (dorsiflected)—in other words, if the origin and insertion of this muscle be approximated—the muscle contracts firmly, keeping the foot in the enforced position, as if frozen into that attitude. The same occasionally occurs if the patient voluntarily extends his foot. Westphal observed the same phenomenon in the disease described by him in which the symptoms of disseminated sclerosis are present, but the corresponding lesion is not visible.¹²¹

¹²⁰ Archiv für Psychiatrie, x. p. 243.

¹²¹ Ibid., xiv. p. 132. It is a noteworthy fact that this sign has been observed by its discoverer also in paralysis agitans.

In a number of cases the mind becomes involved. Simple dementia is the commoner condition, and some indication of passive mental enfeeblement is found sooner or later in the history of the disease in the majority of cases. In addition, there may be a morbid emotional condition, usually in the direction of depression. I have been struck by the frequent association of a melancholic state with large foci in the oblongata. When it is borne in mind that the patient exhibits tremor and speech-disturbance in addition to his mental trouble, it will be understood that with some modifications of the typical signs the case may simulate one of paretic dementia; and there are cases in which it is exceedingly difficult to decide whether they belong to an aberrant type of disseminated sclerosis or to the sclerotic type of paretic dementia. There are some which constitute veritable connecting-links between the two affections.¹²²

¹²² Zacher, Archiv für Psychiatrie, xiii. p. 168; the writer, Journal of Nervous and Mental Diseases, April, 1877, and Insanity, its Classification, Diagnosis, and Treatment, p. 240.

Like tabes dorsalis, the progress of disseminated sclerosis is often marked by episodes. Some of these differ in no way from the visceral crises of posterior-column sclerosis; every form of these symptoms found with that affection may occur in the present one, while episodes involving the cerebral functions are much more common. The latter manifest themselves as apoplectiform or epileptiform seizures. They are preceded by headache and vertigo, or, if these be continuously present, by an aggravation of them; then unconsciousness develops, either accompanied by convulsions or not, and the face is flushed, the pulse full and frequent, and the temperature raised. Consciousness returns in a few hours or a day, the attack rarely lasting more than two days, and it is found that the patient is hemiplegic. But, unlike the hemiplegia found after vascular rupture, embolism, or structural cortical disease, it is rapidly recovered from.

In a case of Gnauck's an attack of scotoma scintillans, associated with a noise of thunder in the right ear and pricking pains on the right side of the face, preceded anæsthesia and the formation of a small defect of the visual field.

There is a close resemblance between these apoplectiform and epileptiform seizures and those of paretic dementia, not alone in clinical character, but also in the surprisingly complete and rapid recovery from the more serious symptoms. But just as in paretic dementia, especially in its advanced stage, each seizure leaves the patient somewhat more impaired in mind and body than he was before, so it is in disseminated sclerosis; each attack marks a step forward in the invasion of the morbid state.

Eye-trouble is much less frequently a premonitory sign of disseminated sclerosis than of tabes. A few such cases are on record. Magnan observed the development of the characteristic symptoms of disseminated sclerosis fourteen years after an amaurosis which followed typhoid; and Gnauck reports another in which first a right ptosis, and then a right amblyopia, preceded the ordinary symptoms. In exceptional cases this premonitory eye-trouble may, like that of tabes, rapidly lead to extreme amblyopia or even amaurosis. The visual disturbances are remarkable for their rapid changes. They appear within a short period, attain their maximum rapidly, and may occasionally retrograde as quickly. They develop under two forms—the central and the peripheral scotoma, or, rather, limitation of the visual or color field. The former, like the amblyopia of alcoholic and nicotine intoxication, consists in an inability to differentiate between red and green in the centre of the visual field. It never, in my experience, proceeds as far as the toxic amblyopias; that is, to the complete extinction of vision.¹²³ The peripheral limitation of vision may be for both quantitative and qualitative light-perception, but it is not, as a rule,¹²⁴ concentric as in tabes, but sector-like.

¹²³ Gnauck says that the central color-blindness may become total, and the red-green blindness extend to the periphery.

¹²⁴ Concentric limitation of ten to thirty degrees has been noted for color-perception.

The atrophy of the optic nerve in disseminated sclerosis is typically partial, in the majority of cases manifesting itself as a sharply-marked discoloration of the temporal half of the papilla. In others the nasal half of the papilla also becomes discolored, but so much less intensely that the difference between the earlier involved and later involved portions is quite easy. It is doubtful whether the subjective visual disturbance is always an indication of the extent to which the optic nerve is involved. There are good reasons for believing those amblyopias and limitations of the field of vision which show marked remissions and exacerbations to be due to some dynamic central condition involving the visual centres and tracts. Thus it has been observed that almost total amaurosis occurred after an apoplectiform attack, to disappear later on. Occasionally the amblyopia is bilateral and the optic-nerve lesion unilateral. The frequency of this affection is stated by Gnauck¹²⁵ as follows: In one half the cases there is diminished vision, and in half this half optic-nerve atrophy with limitation of the visual field. It is only in exceptional cases that an optic neuritis can be determined to have preceded the atrophy.

¹²⁵ Of 50 cases, 22 had no visual trouble, 8 showed simple diminution of perception, 5 added limitation, and 15 changes of the optic disc, a case of total atrophy and amaurosis being included in the latter.

The pupils are perfectly normal in some cases; in others myosis of the spinal type is observed; and this I found to be nearly constant in all advanced cases. Irregularity in outline and inequality exist in a small proportion, and reflex iridoplegia is found in about 10 per cent. of the cases.

Thus far, the symptoms which occur either in a majority or in a large percentage of cases have been enumerated. The typical course of disseminated sclerosis may be stated as consisting in their gradual development and intensification, covering a period of from four to twenty or more years. There are a number of cases in which so many of the symptoms regarded as typical are either absent or where some given symptom-group preponderates over the others to such an extent that they require special mention.

It is not difficult to understand that disseminated sclerosis may ape other forms of spinal disease. Its symptoms depend on the location of the sclerotic foci. If these are situated chiefly in the crossed-pyramid tract, spastic phenomena will predominate, and the case may resemble a spastic paralysis.¹²⁶ If they be distributed in both the posterior and lateral columns, the symptoms will resemble those of a combined form of sclerosis in which the tabic and spastic signs are associated, as far as they do not, in the nature of the case, neutralize each other. This was well shown in a case of De Fleury's. Not infrequently an unusually large focus involves the entire transverse section of the cord, and the case becomes complicated by the symptoms of a transverse myelitis. In such a case, described by Rovigli,¹²⁷ a large transverse focus in the cord had led to ascending secondary degeneration in the column of Goll and descending degeneration of the crossed pyramid tract. In a large series, instances of which are related by Kilian,¹²⁸ Siemens,¹²⁹ Schultze,¹³⁰ Zacher,¹³¹ and Greiff,¹³² the disseminated foci were complicated by a diffuse lesion distributed like that of a diffuse or fascicular myelitis; and there seems to exist every connecting-link between ordinary chronic myelitis, strictly so called, and disseminated sclerosis.

¹²⁶ Gnauck, Neurologisches Centralblatt, 1884, p. 315.

¹²⁷ Rivista sperimentale di Freniatria e di Medicina leqale, x. p. 227.

¹²⁸ Archiv für Psychiatrie, vii. p. 28. He designates this form sclerosis continua multiplex.

¹²⁹ Ibid., x. p. 135.

¹³⁰ Ibid., xi. p. 216.

¹³¹ Ibid., xiii. p. 168.

¹³² Ibid., xiv. p. 287.

Not only does disseminated sclerosis occasionally imitate or approximate the regular (fascicular) affections of the cord, as well as diffuse cerebro-spinal affections, but it may appear under the mask of a nuclear oblongata paralysis.¹³³ And cases are on record where, in addition to the disseminated sclerosis, there occurred sclerotic atrophy of an entire hemisphere or of its capsular tracts, thus leading to a hemiplegic resemblance of the motor paralysis. In my experience the cases presenting the type of a nuclear oblongata paralysis run a more rapidly fatal course than others. The shortest history in my series, one of four years, was of such a case. A number of instances are on record by careful observers—and are probably much more numerous than is commonly suspected—where no decisive evidence of spinal or cerebral disease could be detected during life, and yet disseminated foci of sclerosis existed in the nerve-centres. In such cases the symptoms may be in the direction of simple nervous prostration, more commonly of spinal irritation. I have now under observation a case which for years had been regarded as one of spinal irritation, and which made that impression on me until I discovered the existence of optic-nerve atrophy, which was the only indication that the symptoms depended on gross structural disease.¹³⁴

¹³³ It is customary to speak of symptoms referable to the oblongata as bulbar. The designation bulbus rachidicus is now obsolete, and just as we speak of a capsular hemiplegia, a pons paralysis, or a spinal hemiplegia, so we should say an oblongata paralysis, discriminating between the nuclear, the neural, and the tract affections by means of a prefix.

¹³⁴ At present the symptoms of disseminated sclerosis are unmistakable. Cases are mentioned by Strümpell and others in which they remained indecisive throughout.

Among the anomalous forms of disseminated sclerosis there is one which is characterized by the preponderance of paraplegia and contractures in a combination which is usually found in spinal diseases of a different type. The coexistence of dementia, however, usually enables the observer to determine that the lesion is both cerebral and spinal, although those signs which might enable him to decide the disseminated focal character may be absent.

MORBID ANATOMY.—In advanced cases of disseminated sclerosis the lesion is visible to the naked eye on the surface of the brain and spinal cord. Grayish maculas, sometimes elevated, more rarely a little sunken, and occasionally showing a buff or reddish tinge, are seen on the surface of the spinal cord, the oblongata, pons, and crura. On making sections across the region of the spots, it is found that the color-change is not superficial, but extends inward, involving large parts of the transverse area of the cord or the cerebral axis; and patches lying more deeply in their substance are revealed whose existence could not have been suspected from a mere surface inspection. Exceptionally, patches are found involving the entire transverse section of the spinal cord in a length of a half to two inches. And, similarly, in the brain nearly the entire area of the pons or one of the crura or an entire division of the internal capsule may be occupied by a sclerotic focus. Otherwise, they may vary from almost microscopic dimensions to the size of a chestnut or even larger. Bourneville¹³⁵ has described cases in which the nerve-centres appeared normal to the naked eye, while the microscope revealed the existence of sclerotic foci. It is, however, unlikely that the fresh brain- and cord-tissue, when the site of disseminated sclerosis, will appear perfectly healthy to the naked eye under fairly good illumination. Much less intense lesions than those of disseminated sclerosis reveal their presence by changes in color and consistency.

¹³⁵ Mouvement medicale, 1869, No. 27.

On examining the diseased spots more narrowly, they are found to be slightly diaphanous. Usually, they are rounded or elliptical, but they are often drawn out, as it were, in the most irregular shapes, and not infrequently appear to be the result of a confluence of originally remote and separate foci. In the cord they are sometimes wedge-shaped, extending inward from the periphery. To the touch they appear firm—sometimes not much more so than the normal tissue, contrasting with it as hard-boiled white of egg would contrast with soft-boiled; in advanced cases they become of almost leathery consistency, and there are instances recorded where they actually creaked under the knife. A clear fluid usually runs from their cut surface, and the latter does not jut up on section like normal nerve-tissue.

The distribution of the diseased areas follows no known law. They may be numerous and of large size in one segment of the nervous axis, and small, few in numbers, or even absent, in others. In some altitudes of the cord the lateral, in others the posterior, in still others the anterior, columns are chiefly involved. The cerebrum usually contains a larger number of foci irregularly scattered in the centrum ovale of Vieussens, the internal capsule and its surrounding ganglia, as well as in the corpus callosum. Throughout the nervous axis it seems that the lesion chiefly affects the white substances, and even the roots of the peripheral nerves, both cranial and spinal, are occasionally found to contain small foci, gray, firm in consistency, and as distinctly outlined as those of the central organs.

The morbid process consists in an atrophy and gradual disappearance of the myelin, which is preceded, if not caused, by an increase of the enveloping interstitial substance. This change is of the same character as that found in chronic myelitis. The septa and trabeculæ of connective tissue become thicker, formless connective substance and fibrillar tissue, which seems to arise in, if not in part from, it, constituting the new formation. The neuroglia-nuclei are increased, enlarged, and develop into spider-shaped cells, whose long processes contribute (according to some authors exclusively) to the newly-formed fibrillar network.

While the myelin undergoes wasting, the axis-cylinders remain intact for a long period, and even in intensely sclerosed regions they may be found in nearly their normal number, but naked and in direct contact with the pathological fibrillæ. Some of them become hypertrophied, increasing to twice, thrice, and, according to Leyden, even more, of their normal diameter. This change seems to inaugurate the last phase of the process: the axis-cylinders, becoming sclerosed and brittle, ultimately disappear, and no trace, or at best but doubtful traces, of the normal nerve-tissue are left behind. The blood-vessels, following the rule of the sclerotic process, take part in it. Their walls become thickened, richly nucleated, and the lumen becomes narrowed in consequence. In the smaller vessels complete obliteration of the lumen is sometimes observed.

The gray substance is not involved as frequently as the white, but it opposes no barrier to the extension of the morbid process when once established in its neighborhood. The nerve-cells show the same resistance which the axis-cylinder does; that is, they retain their outline and fibre-connections a long time in the midst of the diseased area. But eventually they become discolored, undergo hyaline or granular disintegration, their processes shrink, and finally they disappear.

Ribbert and Zacher consider the sclerosis of tabes and the disseminated affection to be much more similar than Leyden and Charcot supposed. They locate the starting-point of the morbid process in the vascular and connective tissues; and Greiff, in harmony with this view, finds that the foci occur most frequently in those parts of the cord where the connective-tissue trabeculæ are most numerous, as in the posterior columns and at the junction of the anterior and lateral columns.

Although the morbid foci appear to the naked eye to be uniform, and to be sharply demarcated in the normal tissue, closer examination shows that the areas of maximum lesion are surrounded by a narrow transition zone by which the lesion seems to mark its eccentric progress, and occasionally a focus of intense disease lies in a diffused area of slight changes, resembling those of diffuse myelitis. Sometimes the cord appears to be almost continuously involved by a lesion of moderate intensity, and a few disseminated foci in the brain alone prove that the case belongs to this form of sclerosis.

A few years ago Greiff described what he considered a new lesion in multiple sclerosis, under the name of disseminated vitreous degeneration of the cerebral cortex.¹³⁶ I have been familiar with this lesion since 1876: it can be produced at will in perfectly healthy brains, and consists in a precipitation of leucine crystals extracted from the brain-substance by the action of alcohol. His accompanying figure¹³⁷ represents this artificial lesion very accurately; and Greiff, if he fails to recognize that his vitreous degeneration is a spurious lesion, at least identifies it with the miliary sclerosis of Bucknill and Tuke and the spheres of Schüle, which are now generally recognized to be the results of post-mortem manipulations and not actual lesions.¹³⁸

¹³⁶ Archiv für Psychiatrie, xiv. p. 286.

¹³⁷ Ibid., xiv., Plate ii. Fig. 5.

¹³⁸ Attention was first called to the artificial nature of these bodies by the writer in the Journal of Nervous and Mental Diseases, October, 1877, and a more accurate description was given in the Chicago Medical Review of 1880, and in a demonstration before the New York Neurological Society in 1883. In commenting on the latter a German critic stated that the facts related had been long known in Germany (Neurologisches Centralblatt, 1883, p. 283). On inquiring of the critic what publication contained any reference to this discovery, he frankly stated that he knew of none, but had had in mind what he considered a tradition of the laboratory. It was in the same year that Greiff worked at the Heidelberg laboratory under the eminent supervision of Fürstner, and it was a few years previous that Schüle, one of the collaborators of Ziemssen's Cyclopædia, had made the same mistake. So it seems that the tradition is in some danger of expiring, and that it would do no harm to accept the caution, even though it travel across the Atlantic in the reverse of the usual direction. It has been amply confirmed by Savage and Plaxton (Journal of Mental Science, October, 1882, and April, 1883).

In judging as to the nature and intensity of the inflammatory process which leads to the development of the sclerotic foci, it must be remembered that we are acquainted thus far only with the terminal period of the disease, when, as is to be presumed, the active inflammatory changes have gone by or are in the background. It is very probable that the newly-formed tissue is more nucleated in early periods than is found in the cases which constitute the material of pathological laboratories. In a case of protracted nervous exhaustion accompanied by spinal irritation in an alcoholic subject who was murdered, and whose brain and cord I had an opportunity of examining, I found, both in the cord and brain, districts in which the white substance showed a slight grayish discoloration and increased consistency. Minute examination failed to show any qualitative change in the conducting elements, but the interstitial tissue was hypertrophied, richly nucleated, and showed Frommann's cells in abundance.

ETIOLOGY.—Heredity has been observed in a number of cases by Duchenne, Erb, and Frerichs. The latter two had each an opportunity of recording this inheritance in several members—sisters or brothers—of the same family. In these cases the transmitted affection developed in adult life. Dreschfeld, however, cites a case where two brothers developed its symptoms in a marked degree in infancy. As an associated feature it is found with some cases of congenital defect. Thus Pollak¹³⁹ discovered disseminated sclerosis in an infant which had a defective corpus callosum and exhibited the characteristic signs of the focal affection side by side with the imbecility due to imperfect cerebral development. As a rule, the disease is developed after the twentieth year. But cases have been related (De Fleury) where the patient developed the disease and died with an apoplectiform onset in earlier life. One of the youngest on record is described by Hödemacker.¹⁴⁰ The subject developed the disease at the seventh year, and died with it at the fourteenth, having shown the characteristic symptoms, besides more muscular atrophy than is common. The sclerosis in this case belonged to the type which has been referred to as a connecting-link between diffuse and disseminated sclerosis. Pelizæus¹⁴¹ reports five cases developing in the same family in early life, corresponding somewhat in their relation to multiple sclerosis of advanced life, as the family forms of tabes and spastic paralysis correspond to the typical adult forms of those diseases. All the cases were of males, and the ancestral taint had been present in male members of the family, passing through the females to their progeny without breaking out in the mothers. Each branch of this family appeared to develop its own peculiar type of the disorder.

¹³⁹ Deutsches Archiv für klinische Medizin, Bd. xxiv. p. 404.

¹⁴⁰ Ibid., vol. xxiii. p. 442.

¹⁴¹ Archiv für Psychiatrie, xvi. p. 698.

CAUSES.—Disseminated sclerosis may develop as a sequel of an acute myelitis. An excellent observation of Singer,¹⁴² in which a unilateral optic-nerve atrophy of central origin occurred after recovery from an acute inflammation of the cord, proves that sclerotic foci may develop secondarily to an acute process. Westphal believes that obstruction to the circulation, both of blood and lymph, in the cord may act as a predisposing factor in the production of multiple sclerosis. He rests this opinion on a case where the cord had been compressed by a tumor, and sclerotic foci of probably later date were found in the neighboring segments of the cord.

¹⁴² Prager medizinisch Wochenschrift, 1885, No. 8.

The myelitic affection discovered by the same observer¹⁴³ to be an occasional sequel of typhus, smallpox, diphtheria, measles, and erysipelas is a true disseminated sclerosis. The foci are usually very small and very numerous. A focal sclerosis of the posterior columns of the disseminated type has been found by Brigidi-Bandi in a case of pellagra which presented ataxic symptoms.¹⁴⁴

¹⁴³ Archiv für Psychiatrie, iii. p. 376, iv.; Oertel, Deutsches Archiv für klinische Medizin, viii.; Damaschino, Gazette médicale de Paris, 1871, p. 505. In one case now under observation a typical disseminated sclerosis developed in a robust young man of thirty after typhoid fever.

¹⁴⁴ Lo sperimentale, December, 1879.

Among the exciting causes, prolonged exposure to wet and cold are acknowledged to occupy an important position. The frequent combination of these factors with over-exertion and depressing emotions among the poorer classes probably account for its great frequency among them. In some cases excessive grief has been the only discoverable etiological factor: in three of my own cases this was so prominent and connected a feature that I could not doubt its influence, if not as a primary at least as an exciting cause.¹⁴⁵ Fright has been distinctly connected with the outbreak of the disease in a number of cases.¹⁴⁶ There is considerable unanimity among observers regarding the effects of shock and injury in producing disseminated sclerosis, usually of that anomalous type which approximates the diffuse or fascicular form. Railway spine is undoubtedly the mask of a disseminated inflammatory trouble in a number of cases; the only authority of weight who opposes this view is Charcot, and his opposition is abundantly neutralized by a number of carefully-studied American and European cases.

¹⁴⁵ The coincidences among these three cases were remarkable. All three were Germans, all three musicians, two had lost an only son. In all, the emotional manifestations were pronounced from the initial to the advanced period of the disease.

¹⁴⁶ A Bohemian cigar-maker was startled by the sudden firing of a pistol-shot in a dark hallway, and on arriving at the factory, and not fully recovered from the first fright, he was again startled by the sudden descent of an elevator and the fall of a heavy case from it close to where he stood. From the latter moment he trembled, and his tremor continued increasing till the last stage of his illness was reached. This was my shortest duration, four years, and of nuclear oblongata paralysis type.

Hysterical and other obscure neuroses have been claimed to act as predisposing causes. But, inasmuch as it is well established that sclerosis is not a legitimate sequel of even the most aggravated forms of true hysteria,¹⁴⁷ and, on the other hand, that disseminated sclerosis, particularly in the early stages, may progress under the mask of spinal irritative or other neuroses, it is reasonable to suppose that cause and effect have been confounded by those who advanced this view. According to Charcot, the female sex shows a greater disposition to the disease than the male. Erb, who bases his remarks on the surprisingly small number of nine cases, is inclined to account for Charcot's statement on the ground that it was at a hospital for females that Charcot made his observations. On comparing the figures of numerous observers, it will be found that in the experience of one the females, and of the other the males, preponderate. In my own experience the males far exceed the females both in private and in dispensary practice. Of 22 cases with accessible records, only 7 were females.

¹⁴⁷ Charcot's observation of lateral sclerosis in hysterical contracture, although made so long ago, has not been confirmed, and the most careful examinations in equally severe and protracted cases have proven altogether negative.

Syphilis has also been assigned as a cause. The connection is not as clear as in tabes. In the few cases where there appears to be a direct causal relation the lesion is not typical. There are sclerotic foci, but in addition there is a general lesion, particularly of the posterior columns of the cord, such as is found with paretic dementia. And it has been noted that periendymal and subendymal sclerosis is more frequent with the cases of alleged syphilitic origin than with those of the typical form.

DIFFERENTIAL DIAGNOSIS.—In view of what has been already stated regarding the numerous clinical types found in disseminated sclerosis, it is easily understood why the diagnosis of this disease is becoming more and more uncertain: every new set of researches removes some one or several of the old and cherished landmarks; and it may be safely asserted that only a minority of the cases show that symptom-group which was formerly claimed as characteristic of all. The discovery of a series of cases by Westphal,¹⁴⁸ in which the typical symptom-group of Charcot was present, but no sclerosis deserving the name found after death, as well as the interesting experience of Seguin, who found well-marked disseminated sclerosis in a case regarded as hysterical intra vitam, illustrates the increasing uncertainly of our advancing knowledge. It was believed within a few years that the presence of cranial nerve-symptoms was a positive factor in determining a given case to be one of disseminated sclerosis, but in the very cases described by Westphal such symptoms were present notwithstanding the lesion was absent. Up to this time, however, no case has been discovered in which, optic-nerve atrophy being present in addition to the so-called characteristic symptoms of intention tremor, nystagmus, and scanning in speech, disseminated foci of sclerosis were not found at the autopsy. This sign may be therefore regarded as of the highest determining value when present; but as it is absent in the majority of cases, its absence cannot be regarded as decisive. The presence of pupillary symptoms also increases the certainty of the diagnosis when added to the ordinary and general symptoms of the disorder related above.

¹⁴⁸ Archiv für Psychiatrie, xiv. p. 128.

Although the difference between the tremor of typical disseminated sclerosis and that of paralysis agitans is pathognomonic, yet the existence of a group of cases of disseminated sclerosis, as well as of one of cases of paralysis agitans without tremor, renders an exact discrimination in all cases impossible. It is a question, as yet, whether the form of paralysis agitans without tremor described by Charcot, and which is marked by pains in the extremities, rigidity, clumsiness, and slowness of movement, general motor weakness, a frozen countenance, impeded speech, and mental enfeeblement, is not in reality a diffuse or disseminated sclerosis.

The diagnosis of this disease, while readily made in a large number of cases on the strength of the characteristic symptoms detailed, may be regarded as impossible in a minority which some good authorities incline to regard as a large one.

Diffuse Sclerosis.

SYNONYMS.—Chronic myelitis, Diffuse myelitis, Simple or Diffuse spinal sclerosis, Chronic transverse myelitis, Sclerosis stricte sic dicta (Leyden, in part), Gray degeneration.

The various forms of sclerosis thus far considered were at one time considered as varieties of chronic myelitis, and under different names, founded on leading symptoms, were considered to be merely local, and perhaps accidental, variations of one and the same morbid process. More accurate clinical and pathological analysis has separated from the general family of the scleroses one clearly demarcated form after another. Tabes dorsalis, disseminated sclerosis, amyotrophic lateral sclerosis, and the combined forms of sclerosis have been successively isolated. Still, a large number of cases are left which cannot be classified either with the regular affections of the cord, limited to special systems of fibres, or with the disseminated form last considered. They agree with the latter in that they are not uniform; they differ from it in that they are not multilocular. Not a few modern authors have neglected making any provisions for these cases, while others treat of them in conjunction with acute myelitis, of which disease it is sometimes regarded as a sequel. The term diffuse sclerosis is here applied to those forms of chronic myelitis which follow no special rule in their location, and to such as are atypical and do not correspond in their symptomatology or anatomy to the more regular forms of sclerosis. In regional distribution the foci of diffuse sclerosis imitate those of acute myelitis: they may be transverse, fascicular, or irregular.

MORBID ANATOMY.—In typical cases the lesion of diffuse sclerosis constitutes a connecting-link between that of the disseminated form and posterior sclerosis. Its naked-eye characters are the same. There is usually more rapid destruction of the axis-cylinders, more inflammatory vascularization, proliferation of the neuroglia-nuclei, and pigmentary and hyaline degeneration of the nerve-cells, than in the disseminated form.

Syphilitic inflammation of the cord extends along the lymphatic channels, including the adventitial spaces, and leads to a diffuse fibrous interstitial sclerosis. In one case in which I suspected syphilis, though a fellow-observer failed to detect it after a rigid search, I found a peculiar form of what would probably be best designated as vesicular degeneration, according to Leyden, though associated with a veritable sclerosis. The lymph-space in the posterior septum showed ectasis; the blood-vessels were sclerotic, and each was the centre of the mingled sclerotic and rarefying change. It appears that while the interstitial tissue hypertrophied, the myelin of adjoining nerve-tubes was pressed together till the intervening tissue underwent pressure atrophy. The result was, the myelin-tubes consolidated, some axis-cylinders perished, others atrophied, a few remained, and, the myelin undergoing liquefaction, long tubular cavities resulted, running parallel with the axis of the cord, and exposed as round cavities on cross-section (Fig. 32). The changes in the cells of the anterior horn in the same cord (Fig. 33) illustrate one of the common forms of disease to which they are subjected in the course of sclerotic disease.

FIG. 32.

FIG. 33.

The so-called myelitis without softening, or hyperplastic myelitis of Dujardin-Beaumetz, which is ranked by Leyden and Erb among the acute processes, properly belongs here. It is characterized by a proliferation of the interstitial substance, both of its cellular and fibrillar elements. The nerve-elements proper play no part, or at best a very slight or secondary one. In the sense that this affection occurs after acute diseases and develops in a brief period it may be called an acute myelitis, but both in its histological products and its clinical features it approximates the sclerotic or chronic inflammatory affections of the cord. As far as the clinical features are concerned, this is particularly well shown in the disseminated myelitis found by Westphal after acute diseases, such as the exanthematous and continued fevers.

CLINICAL HISTORY.—Impairment of motion is the most constant early feature of chronic myelitis; in the transverse form it may be as absolute as in the severest forms of acute myelitis; as a rule, however, it is rather a paresis than a paralysis. The patient is usually able to walk, manifesting the paraparetic gait: he moves along slowly, does not lift his feet, drags them along, makes short steps; in short, acts as if his limbs were heavily weighted. This difficulty of locomotion is preceded and accompanied by a tired feeling before other sensory symptoms are developed. Rigidity of the muscles, like that found in disseminated sclerosis, is a common accompaniment, and may even preponderate over the paresis to such an extent as to modify the patient's walk, rendering it spastic in character. In such cases the muscles feel hard to the touch, and the same exaggerated reflex excitability may be present as was described to be characteristic of spastic paralysis.

If, while the leg is slightly flexed on the thigh, the foot be extended,¹⁴⁹ so as to render the Achilles tendon and the muscles connected with it tense, and the hand while grasping the foot suddenly presses the latter to still further extension, a quick contraction occurs, which, if the pressure be renewed and kept up, recurs again and again, the succession of the involuntary movements resembling a clonic spasm. This action is termed the ankle-clonus or foot-phenomenon. Gowers has amplified this test of exaggerated reflex excitability by adding what he calls the front-tap contraction. The foot being held in the same way as stated above, the examiner strikes the muscles on the front of the leg; the calf-muscles contract and cause a brief extension movement of the foot. It is believed that the foot-clonus and the front-tap contraction are always pathological, but a few observers, notably Gnauck, leave it an open question whether it may not occur in neurotic subjects who have no organic disease. Gowers considers the foot-clonus found in hysterical women as spurious, and states that it differs from the true form in that it is not constant, being broken by voluntary contractions, and does not begin as soon as the observer applies pressure. But I have seen the form of clonus which Gowers regards as hysterical in cases of diffuse sclerosis. With regard to the front-tap contraction, its discoverer¹⁵⁰ admits that it may be obtained in persons in whom there is no reason to suspect organic disease. It is significant only when unequal on the two sides.

¹⁴⁹ By extension the approximation of the dorsal surface to the tibial aspect of the leg—what some German writers call dorsal flexion—is meant.

¹⁵⁰ Gowers, The Diagnosis of the Diseases of the Spinal Cord, 3d ed., p. 33.

In severe cases contractures are developed in the affected muscular groups, being, as a rule, preceded by the rigidity, increased reflex excitability, and the thereon dependent phenomena above detailed. These contractures may be like those of spastic paralysis, but usually the adductors show the chief involvement, and sometimes the leg becomes flexed on the thigh and the thigh on the abdomen in such firm contraction that the patient, albeit his gross motor power is not sufficiently impaired, is unable to move about, and is confined to his bed, his heel firmly drawn up against his buttock. It is stated by Leyden that the contracted muscles occasionally become hypertrophied—an occurrence I have not been able to verify. As a rule, some muscular groups are atrophied, though the limbs as a whole, particularly in those patients who are able to walk about, are fairly well nourished.

Pain in the back is a frequent accompaniment of diffuse sclerosis. It is not pronounced, but constant.

The drift of opinion to-day is to regard pain in the spinal region as not pathognomonic of organic spinal affections. It is true that pain is a frequent concomitant of neuroses, and that it is more intense and characteristic in vertebral and meningeal disease; but in denying a significance to pain in the back as an evidence of diffuse disease of the cord itself, I think many modern observers have gone to an extreme. It is particularly in diffuse sclerosis that a dull heavy sensation is experienced in the lumbo-sacral region; and in a number of my cases of slowly ascending myelitis and of tabes dorsalis the involvement of the arms was accompanied by an extension of the same pain, in one case associated with intolerable itching, to the interscapular region. It cannot be maintained that the pain corresponds in situation to the sclerotic area. It is probably, like the pain in the extremities, a symptom of irradiation, and corresponds in distribution to that of the spinal rami of the nerves arising in the affected level.

As the posterior columns are usually involved in transverse myelitis, the same lancinating and terebrating pains may occur as in tabes dorsalis. As a rule, they are not as severe, and a dull, heavy feeling, comparable to a tired or a burning sensation, is more common. A belt sensation, like that of tabes, and as in tabes corresponding to the altitude of the lesion, is a much more constant symptom than acute pains.

Cutaneous sensibility is not usually impaired to anything like the extent found in advanced tabes. It is marked in proportion to the severity of the motor paralysis; where mobility is greatly impaired, profound anæsthesia and paræsthesia will be found; where it is not much disturbed, subjective numbness, slight hyperæsthesia, or tingling and formication may be the only symptoms indicating sensory disturbance; and there are cases where even these may be wanting.

The visceral functions are not usually disturbed. In intense transverse sclerosis of the upper dorsal region I observed gastric crises, and in a second, whose lesion is of slight intensity, but probably diffused over a considerable length of the cerebro-spinal axis, there is at present pathological glycosuria. The bladder commonly shows slight impairment of expulsive as well as retaining power, the patients micturating frequently and passing the last drops of urine with difficulty. Constipation is the rule. The sexual powers are usually diminished, though rarely abolished. As with sclerotic processes generally, the sexual functions of the female, both menstrual and reproductive, are rarely disturbed.

It is not necessary to recapitulate here the symptoms which mark diffuse sclerosis at different altitudes of the cord. With this modification, that they are less intense, not apt to be associated with much atrophic degeneration, nor, as a rule, quite as abruptly demarcated in regional distribution, what was said for acute myelitis may be transferred to this form of chronic myelitis. The progress of diffuse sclerosis is slow, its development insidious, and the history of the case may extend over as long a period as that of diffuse sclerosis. Sooner or later, higher levels of the cord are involved in those cases where the primary focus was low down. In this way the course of the disease may appear very rapid at one time, to become almost stationary at others. Of three deaths which occurred from the disease in my experience, one, in which there were distinct signs of involvement of the oblongata,¹⁵¹ occurred from sudden paralysis of respiration; a second from a cardiac complication, which, in view of some recent revelations concerning the influence of the tabic process on the organic condition of the valves of the heart, I should be inclined to regard as not unconnected with the sclerosis; and in a third, from bed-sores of the ordinary surgical variety. The malignant bed-sore is not of frequent occurrence in this disease.

¹⁵¹ On one occasion the patient had momentary anarthria, followed a day later by two successive periods of anarthria, lasting respectively about twenty seconds and one minute, one of which was accompanied by diplopia of equally brief duration.

PROGNOSIS.—The disease may, as in the instances cited, lead to a fatal termination, directly or indirectly, in from three to twenty years. The average duration of life is from six to fifteen years, being greater in cases where the sclerotic process is of slight intensity, even though it be of considerable extent, than where it is of maximum or destructive severity in one area, albeit limited. I am able to say, as in the case of tabes dorsalis, that a fair number of patients suffering from this disease whom I have observed for from two to six years have not made any material progress in an unfavorable sense in that time. One cure¹⁵² occurred in this series, of a patient manifesting extreme contractures, atrophies, bladder trouble, and ataxiform paresis, where the cause was plainly syphilis, and the histological character of the lesion is somewhat a matter of conjecture in consequence. Diffuse sclerosis of non-syphilitic origin—and this may apply also to established sclerosis in syphilitic subjects—is probably as unamenable to remedial treatment as any other sclerotic affection.

¹⁵² The patient went, under direction of Leonard Weber and R. H. Saunders, to Aix-la-Chapelle, where this happy result was obtained after mixed treatment had practically failed.

The same rules of DIAGNOSIS applicable to transverse myelitis of acute onset apply, level for level, to the diagnosis of transverse myelitis of insidious development, the history of the case often furnishing the only distinguishing point between the acute and the chronic form.

The main difference between the diffuse sclerosis and acute myelitis, clinically considered, consists in the gradual development of symptoms in the former as contrasted with their rapid development in the latter disease. Acute myelitis is established within a few hours, days, or at most, in the subacute forms, a few weeks; chronic myelitis requires months and years to become a clearly-manifested disorder. It is the essential correspondence of the symptoms of both conditions, intrinsically considered, which renders it impossible to distinguish clinically and in the absence of a history of the case between some cases of acute myelitis in the secondary period and the processes which are primarily of a sclerotic character.

It is unusual to find the degeneration reaction in myelitis of slow and gradual development. Sometimes there is diminished reaction to both the faradic and galvanic currents, or the so-called middle form of degeneration reaction is obtained from atrophied muscles, the nerve presenting normal or nearly normal irritability, and the muscle increased galvanic irritability and inversion of the formula.

Among the less reliable or accessible points of differentiation between the residua of acute myelitis and the chronic form is the history of the onset and the age of the patient at the time of the onset. Myelitis in young subjects is more likely to be of the acute kind; in older persons it is more apt to be chronic.

In the diagnosis of diffuse sclerosis the question of differentiation from neuroses not based on ascertainable structural disease, such as are called functional, will be most frequently raised. In differentiating between organic and functional spinal disorders all known exact signs of organic disease must be excluded before the case can be considered as appertaining to the latter group. Symptoms of hysteria, nervous exhaustion, and spinal irritation frequently coexist with diffuse sclerosis as well as with the disseminated form; and this is not surprising, for, instead, as seemed at one time to be believed, of the neurotic taint granting comparative immunity against organic disease, it is the reverse, and it is not at all uncommon to find a strongly-marked neurotic diathesis in the family history of sufferers from diffuse sclerosis. That ordinary hysteria, epilepsy, and what is vaguely called nervousness are common features in the ancestral record of the hereditary forms of spinal disease has already been stated in considering those affections.

One of the commoner forms of the grave phase of hysteria is paraplegia.¹⁵³ Often muscular atrophy—which ensues from disuse—exaggeration of the deep reflexes, and retention of urine are added to the paraplegia and heighten the resemblance to an organic affection. Its development, though sometimes sudden, often occupies weeks or months, and may be preceded, exactly as in chronic myelitis, by weakness in the legs, and not infrequently by combined ataxia and weakness. It is much more difficult to discriminate here than is generally held or than is enunciated in textbooks. The sufferer from hysterical paraplegia does not always give other indications of the hysterical neurosis, and even if she did show a globus and tenderness at certain points, it is a question whether it could be called a scientific diagnosis which determined the case to be one of functional trouble on these signs alone. More than one error has been committed in this respect. In chronic myelitis retention of urine is less common than incontinence, which is the reverse of hysterical paraplegia. Pupillary symptoms do not occur with the latter affection. If there be sensory anæsthesias, they are bizarre in character or distribution, and do not usually harmonize with the distribution of the paralysis. In most cases moral influences can be exerted so as to increase the power of movement far beyond what would be possible in an organic disease; and while an electrical examination will not always yield positive results in chronic myelitis, yet no case of chronic myelitis with complete or nearly complete paraplegia but will show at least quantitative changes of such extent as to prove beyond doubt that the case is of an organic character.

¹⁵³ I have observed for two years a stationary brachial diplegia, of undoubted hysterical origin, although the patient had never shown any ordinary hysterical manifestations, and had had no other hysterical symptom than chromatopsia, and that only for a short period. From its long duration, constancy, and the resulting atrophy of disuse it had been regarded as a case of peculiarly limited chronic myelitis.

There is one point in which spinal and cerebral disease involving the motor tract differs in the majority of cases, which may be utilized in distinguishing obscure affections of the former from those of the latter kind. In cerebral paralysis of any standing the superficial reflexes, such as the cremaster and abdominal reflexes, are usually diminished or abolished, while the deep or tendon reflexes are exaggerated. In spastic conditions due to spinal disease—say sclerosis of any kind affecting the lateral column and leaving the motor nuclei of the anterior cornua unaffected—the deep reflexes are similarly increased, but the cremaster reflex is increased also.¹⁵⁴ This feature of the superficial reflexes is significant in the case of cerebral disease only when unilateral.

¹⁵⁴ Attention has been called, I believe, by Westphal, to the fact that the cremaster reflex may not be demonstrable when reflex excitability is at its highest, because the cremaster muscle is already in extreme spastic contraction.

The initial period of diffuse sclerosis is sometimes confounded with rheumatism—an error less pardonable than in the case of tabes, inasmuch as in diffuse sclerosis the pains are not usually premonitory, but associated with motor paresis. It is erroneous to regard a pain as rheumatic because it is aggravated or relieved by changes in the weather. There are many subjects of myelitis who regard themselves as veritable barometers, and with more justice than most rheumatic patients.

In some cases of chronic alcoholism there are motor weakness and a gait much like that of diffuse sclerosis.¹⁵⁵ It is to be remembered that the solar tickling reflex is very often abolished in alcoholic subjects, and profound diminution of the normal cutaneous sensibility of the leg and feet usually coexist. But unless there is peripheral neuritis—which is an exceptional and, when present, well-marked affection—the absence of profound nutritive changes of the muscle, the presence of the alcoholic tremor, the absence of sphincter and bladder trouble, and the great variation of the symptoms from week to week, and even from day to day, serve to distinguish the alcoholic spinal neurosis from myelitis.

¹⁵⁵ Wilks' alcoholic paraplegia.

The Secondary Scleroses.

In studying the lesions underlying the symptoms of organic spinal disease, the occurrence of fascicular scleroses, secondary to such disease and due to the destructive involvement of nerve-tracts, was repeatedly noted. Türck may be regarded as the discoverer of these degenerations, and the reliability of this old observer may be inferred from the fact that one bundle of fibres liable to individual degeneration still goes by his name, and that, as far as he was able to discriminate between the various paths which secondary degenerations follow through the cerebro-spinal fibre-labyrinth, his statements have not been materially modified by more recent investigators, such as Bouchard, Vulpian, and Westphal.

The discovery by Meynert that the great cerebro-spinal tracts attain the white color which they owe to the development of myelin around their component axis-cylinders with advancing maturity, and that the tracts of noblest, and therefore most intelligent, function were the last to show this sign of maturity, was greatly extended by Flechsig, who found that each tract receives its myelin at a definite period of intra-uterine life, the lowest or the nerve-roots first; then the short or intersegmental or—as the physiologist may call them—the automatic tracts; then the long or controlling tracts; and last, the associating tracts of the cerebral hemispheres which mediate the complex relations underlying mental action. It was this discovery which gave a new impulse to the study of the secondary affections of the cord and brain. The accuracy with which secondary degeneration follows the lines marked out by the normal course of the tract is as great, diminishing when the tract diminishes, changing its position or direction and decussating where the latter changes its direction or position or decussates, that it constitutes not alone an interesting subject for pathological study, but has become one of the most reliable guides of the cerebral anatomist. It is of great importance to the pathologist to be able to differentiate between the primary disease and its secondary results, and, as the controversy concerning the so-called system diseases shows, even the most studious observers are uncertain in this direction in many cases.

MORBID ANATOMY.—Secondary degeneration manifests itself by a discoloration of the affected nerve-tract, which accurately corresponds in area to the normal area of that tract. The more recent the degeneration the less pronounced is this change. In advanced cases the color may be a dark gray, in moderately old ones a reddish or yellowish gray, and in those of very recent origin no change may be visible to the naked eye. It is claimed, however, that even here a loss of translucency of the white substance, giving it a sort of cheese-like opacity, may be detected. On hardening the specimen containing the degenerated tract in Müller's fluid or a simple bichromate salt solution, the affected area, instead of appearing dark on section in contrast with the gray substance—which in such preparations appears yellowish or a light brown—contrasts with the former by its lighter tinge. This contrast is observable even in cases where the naked eye was unable to detect the change in the fresh specimen. It can be sometimes found as early as the tenth day after the primary lesion, and is apparently simultaneously developed in the whole length of the nerve-tract affected.

The minute changes characterizing secondary degeneration begin in the essential conducting elements, the axis-cylinder, which exhibits a finely granular or molecular disintegration, and disappear. According to Homén, it shows an initial swelling and a failure to stain properly before this. The myelin then follows suit: it becomes fragile, forms variously-shaped globules, and also disappears, and together with this a nuclear proliferation is noticed in the interstitial substance; fatty granule-cells are observed in large numbers, and manifest a tendency to accumulate in the perivascular districts. These cells are not permanent; their gradual diminution is accompanied by a proliferation of the interstitial tissue, which ultimately appears as a pure connective substance composed of fine fibrillæ arranged in undulating bundles. The entire process may be not inaptly compared to an hypertrophy of the interstitial substance resulting from overfeeding of its cellular elements by the morbid pabulum furnished through the disintegration of the nervous substance proper.

The disappearance of the nerve-tubes, and the formation of a new tissue in their place, which, like all tissues of the same character, undergoes shrinkage, leads to considerable deformity in the shape of the part which is the site of secondary degeneration. This is seen in the accompanying figure, where in an old-standing secondary degeneration of one interolivary layer the corresponding half of the medulla is greatly reduced in diameter as compared with the other side (Fig. 34), and the entire raphé is distorted. When one side of the cord is the site of such a change a similar asymmetry results.

FIG. 34.

Secondary Degeneration of Interolivary Layer: D Ds D, degenerated area; r, the distorted raphé.

According as the original lesion is incompletely or completely destructive, a larger or fewer number of axis-cylinders may be found preserved in the sclerotic tissue. It is not yet determined whether in some instances these fibres may not represent an admixture from another source than are comprised in the mainly affected tract.

Secondary degenerations are classified as ascending and descending. An ascending degeneration is one which is found situated brainward of the primary lesion; a descending one is found caudad of the lesion. It was once maintained that the direction of the secondary degeneration was constant for each individual tract. This seems to be true for a few. Some tracts, particularly in the brain, degenerate on both sides of the lesion, as I showed with regard to the interolivary layer.

The best studied form of secondary degeneration is that of the voluntary motor conduit known as the pyramid tract. Beginning in the so-called motor area of each cerebral hemisphere, the Rolandic loop passes into the anterior part of the posterior half of the internal capsule, to be thence continued through the crus, pons, and the pyramids of the oblongata to the decussation or crossing-point of the pyramids. Here the greater part of the tract crosses into the opposite lateral column, occupying the position described in the section on Spastic Paralysis. A smaller part remains on the same side of the continuous interpyramidal and ventro-spinal fissure, constituting the direct fasciculus of Türck.

The crossed-pyramid tract diminishes as it passes caudad in the cord, giving off its fibres to the lateral reticular processes of the cord, whence—whether interrupted by cells (Von Monakow) or not—they probably reach the great cells in the gray substance from which the anterior rootlets spring. The direct fasciculus probably terminates in a similar way, and perhaps makes good, as it were, its failure to participate in the gross decussation at the level of the foramen magnum by decussating in detail along its entire length. It is usually exhausted before the lumbar cord is reached, whereas the crossed tract in the lateral column continues down as low as the origin of the sacral nerves. A destructive lesion anywhere in the course of the pyramid tract, whether it be in the motor area of the cortex, in the loop of Rolando, in the internal capsule, the pons, or the cord itself, will provoke descending degeneration; that is, sclerosis of so much of the tract as lies below the lesion. Thus such degeneration is found with porencephalic defect of the motor area. I found it in a paretic dement who had extensive cortical destruction following a submeningeal hemorrhage. It has been observed after focal lesion of the pons (Homén, Schrader), and after transverse lesions of the cord, either myelitic, traumatic, or as the result of compression by vertebral disease. As a rule, the cells in the anterior horn are not involved, and some observers question whether this ever occurs. I have never found such involvement, although in its gross dimensions the anterior horn as a whole appears atrophied. This atrophy I have been able to account for satisfactorily by the disappearance of many of the fibres which run into the gray substance from the reticular processes.

While the distribution of degeneration in the cord is rather uniform, varying only in harmony with the ascertained individual variations in the relative preponderance of the crossed and uncrossed parts of the pyramid tract, there is much more variation in the cerebral distribution of the degeneration according to the extent of the original lesion. Thus, if the entire capsule be destroyed, the greater part of the crus is involved. If only the posterior division in its anterior part be destroyed, the degeneration is in the crus, limited to that part which runs a subpial course on the crural demi-cylinder, occupying from a fifth to a third of its surface-area. Still more limited degenerations are described, but as yet are too few in number to base other than tentative conclusions on them. Among these is one occupying a thin strip on the inner side of the crus, which degenerates after lesions near the genu of the capsule, and probably represents the tract which governs the cranial nerve-nuclei. An excellent observation by Von Mannkopf shows that the course of the motor fasciculus is subject to some individual variation even within the capsule.

A number of forms of secondary degeneration are described, involving intracerebral tracts, such as those connecting the cerebrum and cerebellum. The degeneration of the visual tract, from the optic nerve to the occipital lobe, observed by Richter and Von Monakow, with some conflict of opinion between these observers, is often as perfectly demonstrative of the course of the optic fasciculi as degeneration of the pyramid tract is demonstrative of the course of the voluntary innervation of the muscles moving the limbs.

The secondary degenerations following lesion of the pons varolii are acquiring special interest in view of their relation to special nerve-tracts of the spinal cord of hitherto unknown function. The purest instance of an isolated degeneration of other than the pyramid tract is the case illustrated in the accompanying diagrams. It involved the interolivary layer, was both ascending and descending, being traced above into the subthalamic region, and below decussating into the opposite side of the oblongata, to terminate in the nuclei of the columns of Burdach and Goll. The leading symptom manifested by the patient was a hemiplegia of the muscular sense.¹⁵⁶

¹⁵⁶ Besides my case, others have been recorded by Homén, Meyer (Strassburg), and Schrader, which are impure. In the former and latter degeneration of the pyramid tract, in the second degeneration of the olivary fasciculus, coexisted. It is not generally known that Westphal, in one of the first volumes of the Archives now edited by him, found an ascending degeneration of the same tract for a short distance.

FIG. 35.

Secondary Degeneration of Interolivary Layer, Caudal or Descending Portion: A, in caudal half of pons; B, cephalic end of oblongata; C, middle of oblongata; D, at level of so-called upper pyramidal or interolivary decussation; E, at level of true pyramidal decussation. The atrophy in this level has entirely crossed the middle line; in D it is seen in the act of crossing.

Ascending degeneration is found in a very distinct form after compression of the cauda equina. It is limited to the posterior columns, occupying nearly the entire area of the latter in the lumbar cord, particularly the triangular field of Burdach's column mentioned in the article on Tabes. In the dorsal and cervical cord it is limited to the columns of Goll, and terminates in the clava of the oblongata at the nuclei of those columns.

Higher lesions produce the same ascending degeneration of the column of Goll, and in addition involve other, probably centripetal, tracts which happen to be injured at their origin or in their course. For example, a transverse lesion of the dorsal cord would produce ascending degeneration for its whole length of the column of Goll and of the direct cerebellar tract. In addition, it would, in obedience to the law previously stated, produce descending degeneration of the pyramid tract. This combination is almost a typical sequence of compression myelitis of the cord, as well as of ordinary transverse sclerosis. Recently, Gowers¹⁵⁷ has described a secondary degeneration in such a case of transverse lesion not previously noticed. It is found in cases showing gross disturbance of cutaneous sensibility, and occupies a narrow belt encircling the anterior quarter of the circumference of the crossed-pyramid tract. It is continuous, in my opinion, with a tract which in the upper cervical cord is situated in a corresponding situation, and which degenerated a short distance caudad in a case of secondary degeneration of the olivary fasciculus described by Meyer, and in which similar sensory symptoms were noted.

¹⁵⁷ Diseases of the Spinal Cord, and Neurologisches Centralblatt, 1886.

FIG. 36.

Decussating Degeneration of Interolivary Layer: Dr, Darc, the crossing degenerated fasciculi; Arc, the undegenerated fasciculi, after emerging from the partly sclerosed raphé.

CLINICAL HISTORY.—Secondary degenerations are passive results of other more active processes, and few clinical signs are attributable to them. The most important of these is the contracture which is found in old hemiplegias, and attributed, like the secondary exaggeration of deep reflexes in such, to the descending degeneration of the pyramid tract. Bouchard believed that it was the retraction of the sclerotic strand which acted as an irritant on the neighboring fibres. The development of spastic symptoms in amyotrophic lateral sclerosis and in focal lesions of the crossed-pyramid tract is in favor of this view. On the other hand, the occurrence of flaccid hemiplegia, and its conservation for years after the most extensive lesions, is against it, as it is in these very cases that the secondary degeneration is most intense. That the retraction of a longitudinal strand exercises any serious effect on neighboring and parallel fasciculi is questionable, as the process is slow. There is, however, one situation where such influence is very likely to occur—the decussations of the oblongata. In the case already referred to, the retracting sclerosing bundles undoubtedly must have exercised a damaging effect on their fellows of the opposite side, which, interdigitating with them, were compelled to pass through the sclerosing tissue. It has occurred to me that the slight sclerosis which is sometimes observed in the crossed-pyramid tract of the same side of a cerebral lesion, even where that lesion is strictly unilateral, is due to a similar influence. I think it can be shown that such sclerosis cannot be traced to the primary lesion; it begins at the decussation, and it is more than probable that the firm constriction to which the healthy fibres are subjected in crossing through their shrinking fellows of the opposite side is not alone the cause of the symmetrical yet slighter lesion, but also accounts for the observation by Pitrés and Charcot of a slight motor weakness observed on the same side as the hemiplegia, producing lesion in ordinary cases of capsular hemorrhage.¹⁵⁸

¹⁵⁸ Some of the French observers claim that this occurs only in the early period, but a careful study of the matter by R. Friedländer shows that the weakness of the side not usually regarded as involved is found in the later periods, and well marked then (Neurologisches Centralblatt, June 1, 1886).

The PROGNOSIS and TREATMENT of secondary degenerations are practically involved in the primary lesion which gave rise to them. The contractures attributed to secondary sclerosis of the motor tracts is to be treated on the principles mentioned in the following section.

The Treatment of Spinal Sclerosis.

As the histological character of the different forms of sclerosis is similar—at least in the terminal period—the causes producing them identical even in name, and the indications furnished by leading symptoms analogous if not identical, the treatment of these various disorders is naturally based on the same leading principles. There are two objects to be aimed at in dealing with these chronic disorders: The first is the cure or arrest of the morbid process itself; the second is the amelioration of distressing and disabling symptoms.

It is generally recognized that a perfect cure of a sclerosis is a consummation never to be realized by any plan of treatment now at our disposal. The experiments of Kahler and others have shown that spinal tissue, once destroyed, is not regenerated. The post-mortem examination of cases of tabes which were considered as cured during life (Schultze) has shown that the sclerosis had not been removed; the process had merely become quiescent, and the apparent recovery had been due to the vicarization of other nerve-elements than those destroyed for the latter.

But if attempts at the regeneration of destroyed fibres and cells are to be regarded as futile, the arrest of the destructive process is to be considered as an object which offers better chances of realization, and which is worth attempting for other than merely conservative reasons. In a number of the forms of sclerosis described, notably in tabes and the disseminated form, it is remarked that the axis-cylinders lying within the morbid district are in part intact and in part but slightly affected. Here and there groups of nerve-tubes may be found which retain even their myelin. While subject to the vicissitudes inseparable from their position in the midst of active pathological changes, these channels of nerve-force, though anatomically patent, may have their function perverted or destroyed, just as a nerve outside of the cord may be paralyzed by pressure or anæmia though its structure be intact. Should the active phase of the sclerotic process be arrested, these intact or nearly intact fibres will resume their function, and thus an apparent improvement will be effected. The spontaneous ameliorations in the course of tabes dorsalis and the less marked ones of diffuse sclerosis, coupled with temporarily improved sensation in the former and improved motion in the latter disease, show that retrogressions of this character are possible and do occur. How is the physician to imitate the action of nature? how to intensify it so as to secure the permanent improvement which nature unaided does not grant? The first factor to be considered is the removal of the cause of the disease. A number of cases are due to exposure to wet and cold and to over-exertion. Such exposure and over-exertion, if not already rendered impossible by the disease, is to be discontinued. A large number of cases of tabes—according to many authors, a majority—a considerable number of cases of diffuse sclerosis, and not a few of other forms, are connected with the syphilitic dyscrasia. Here, at the very outset, we have a definite indication for treatment, and while we may be disappointed in the results of such treatment in a large proportion of cases, yet enough of well-assured and substantial success has been and is obtained to render it almost a matter of duty for the physician to try antisyphilitic measures in every such instance.

The mixed treatment in chronic spinal disorders should be followed out for long periods and faithfully. Most tabic and other sclerotic subjects affected with constitutional syphilis are in what is called the tertiary period of that disease, when iodide of potassium is less useful than mercury. I have never gained anything by pushing either drug to the extreme point in advanced cases, and it should be borne in mind that mercurialization carried too far may itself prove directly injurious to the nerve-centres.¹⁵⁹ In cases where gastric crises, gross ataxia, muscular atrophy, and bladder disturbance have been of long duration this treatment is rarely successful.¹⁶⁰ But in the initial and early periods of tabes and in diffuse sclerosis of slight intensity the effect is sometimes gratifying, and of such a nature that it cannot be attributed to a coincidence with spontaneous remissions of the disease. In one case both knee-jerks and the pupillary reflexes returned, to disappear on premature discontinuance of the treatment; and on resumption one knee-jerk again returned, and has remained demonstrable now over half a year. In a second case the fulminating pains and the bladder disturbance disappeared, a slight indication of the pupillary reflex developed, and the patient has remained stationary with this gain for a period of three years.¹⁶¹ In a third case, one of established ataxia, with which luetic osseous lesions occurred, the pupillary reflex has returned twice, disappearing after the first reappearance. In one case of combined sclerosis in which no syphilitic antecedents could be found the paresis of the arms has disappeared, and the ataxic paresis of the lower extremities has improved to such an extent that the patient can stand with his eyes closed and his feet together, and on one leg with the eyes open—feats which a year ago he was unable to perform. None of the changes in symptoms taking place in these cases occur spontaneously in sclerotic spinal disorders, and they must be attributed to the treatment. Such treatment is best carried out in conjunction with warm bathing. The Hot Springs of Arkansas, those at Las Vegas, New Mexico, and the baths of Aix-la-Chapelle in Europe enjoy a special reputation in this field. The springs of Arkansas, as regards the intrinsic character of the water, possess advantages which are probably not excelled by any European baths, but the therapeutical management¹⁶² is far from that ideal point of development attained, for example, at Aix-la-Chapelle.

¹⁵⁹ Mendel thus found in his experiments made on dogs, developing cerebral disease from rotation with the head directed toward the axis of rotation, that dogs who had previously received subcutaneous injections of corrosive sublimate showed an increased vulnerability to the action of the rotary apparatus.

¹⁶⁰ A remarkable exception is related in the section on Chronic Myelitis.

¹⁶¹ There was concentric limitation of all color-fields, and only central perception of green; to-day, if anything, the color-fields of this patient are a little greater than in the physiological average. The case was undoubtedly one of initial tabes.

¹⁶² Mercurial ointment is used by the hundredweight, to quote the expression of a patient, and in certain establishments the sufferers from the common taint plaster each other from head to foot, as with mud, with this panacea for most of those ills which flock to the springs. Still, there seems to be no doubt that enormous quantities of mercury are borne well by those who use the baths, and who under other circumstances are susceptible to its most undesirable effects.

Optic-nerve atrophy, according to the best authorities, constitutes a contraindication to the use of mercury in any form. It may be laid down as a general rule that the more rapidly the symptoms indicating a sclerotic process are developed, and the more recent its advent, the more energetically should the treatment be pushed. Mercurial inunctions and the so-called heroic doses of iodide are to be employed. But in cases progressing slowly and of long antecedent history what may be called a dilute plan is more apt to yield good results. Small doses of mercury,¹⁶³ given steadily for years, and iodide of potassium, administered in well-tolerated doses for periods of ten days, alternating with corresponding periods of intermission, have, in my opinion, delayed or arrested the progress of tabes and other forms of sclerosis for the long periods referred to in the preceding sections.¹⁶⁴ Although the antisyphilitic measures adopted in sclerosis of syphilitic origin are the most important, and the prognosis of no such case can be regarded as hopeless as to recovery or duration until they have been tried, other procedures, detailed under the head of Peripheral Treatment, should not be neglected. While some very severe cases improve rapidly on antisyphilitic treatment, other much less severe and more recent cases, in which the same cause is assigned with equal reason, are not affected by it in the slightest visible degree. The reason for this difference is unknown, but it necessitates the bearing in mind that by limiting the treatment to the etiological indication valuable time may be wasted in which the symptomatic indications could be profitably followed.

¹⁶³ The tablet triturates of biniodide of mercury or corrosive sublimate furnished by Fraser & Co. of New York I have found peculiarly useful; one one-hundredth or more of a grain may be thus administered every two to four hours.

¹⁶⁴ I am now employing the same treatment in some cases showing no syphilitic history. If any medicinal measures can act upon connective-tissue proliferation, it is these very ones.

In cases of sclerosis due to other causes than syphilis a number of medicinal agents have been recommended as calculated to affect the central disease directly. Ergot is recommended in sclerotic troubles, particularly tabes, by a large number of writers. It is admitted that this substance can produce tabes itself, so that its administration in the large doses recommended by some is not without its possible dangers. I have seen a patient well advanced in the disease who had received the drug for three weeks consecutively in such quantities¹⁶⁵ that on estimates made I came to the conclusion that he had received more than some of the persons in whom Tuczek discovered the development of ergotin tabes. Favorable results are reported ensuing after its use in the early stages, particularly where signs of irritation preponderated, such as lightning-like pains, hyperæsthesia, and frequent erections; and it has been suggested that the beneficial action is due to an effect on the blood-vessels, which are supposed to be congested in the beginning of the disease. Proof of such congestion has not been furnished: the vessels are usually sclerosed and their lumen narrowed. In view of the undeniable danger which attends the administration of ergot in tabes, it may be properly insisted that its indications be more precisely formulated than has yet been done. It is commonly noticed in the natural progress of tabes that the lightning-like pains disappear, usually about the time the anæsthesia becomes greater. The anatomical parallel is supposed to be the destruction of the nerve-tubes whose previous irritation caused these pains. If, as is claimed—and it seems to be substantiated—ergotin does produce amelioration of the lightning-like pains, it would prove a damaging revelation which showed that it did so in imitation of the natural process; that is, by increasing the sclerosis.

¹⁶⁵ An expert ophthalmoscopist found that the retinal vessels, which were somewhat dilated in this patient, were not influenced by the treatment.

The first drug to which an influence was assigned upon the sclerotic processes, and which has maintained its reputation longest, is nitrate of silver.¹⁶⁶ Its claim to being regarded as a remedy may be best characterized by the fact that an author who is far from being prejudiced against it, and who recognizes the claims of Wunderlich, its advocate, speaks of it as a valuable placebo.¹⁶⁷ I have never obtained any effects from this drug in the scleroses, or from the chloride of gold, which has been also recommended for these affections, nor have I seen any in cases where either or both had been faithfully tried by others for years. The same is to be said of the chloride of barium, which has been warmly extolled on the basis of a very limited trial in disseminated and diffuse sclerosis.

¹⁶⁶ One of the first patients on whom Wunderlich tried this drug died while I studied at Leipzig. He had extensive argyria and sclerosis of the posterior columns.

¹⁶⁷ Leyden, op. cit., vol. ii. p. 359.

The direct application of the galvanic current to the spine is recommended, more particularly by Erb and Neftel.¹⁶⁸ I am unable to state anything regarding currents derived from as many as twenty of Siemens cells and applied in the ascending direction, as the latter recommends beyond an experience which occurred in the practice of a colleague, who, alarmed by the event to be related, referred the patient subjected to this treatment to me. The patient suffered from tabes dorsalis, the symptoms being limited to the lower extremities, the ulnar distribution, and the pupils. The belt was in the lower thoracic region; the ataxia and lightning-like pains were not great. After a single application of an ascending current from twenty-two cells, continued for ten minutes, the patient suddenly felt a severe dull pain in the occiput and terrible lancinating pains in the distribution of the occipital nerves. With this there occurred scintillation before the eyes, and at the subsequent examination I found that the belt sensation had moved into the neck. The coincidence was so close, and sudden changes in the distributional area of tabic symptoms are otherwise so uncommon, that I attributed the observed change to the treatment.

¹⁶⁸ In describing a case in which this measure not only ameliorated lancinating pains and vesical symptoms, but also, applied to the head, relieved the diplopia—usually a spontaneous occurrence, according to both American and European writers—this writer takes occasion to state that in the year 1869 tabes dorsalis was practically unknown to American physicians (Archiv für Psychiatrie, xii. p. 619). Duchenne described progressive locomotor ataxia in that and the preceding year; the necessity of referring to the unfamiliarity of American physicians with a disease not at the time recognized on either side of the Atlantic is hence not apparent. Leyden (op. cit., vol. ii. p. 325) candidly admits that the German medical profession was at first averse to recognizing Duchenne's limitation: this reproach cannot be laid at the door of American physicians, as I can distinctly recollect the demonstration of several well-marked cases exhibiting the characteristic symptoms then known, in the year 1870. The disease obtained recognition in American textbooks and journals as early as in those of any other land.

Erb does not recommend such powerful applications. But the most sanguine electro-therapeutist must admit that the action of galvanic currents on the spinal cord is an exceedingly uncertain one. It is questionable whether weak ones deflect sufficient current-loops to reach the cord and to exert any material effect. As to currents powerful enough to produce an effect, it is not known, except in the loosest and most empirical way, what that effect is. The procedure followed by Erb is to use large electrodes, the cathodal one being a little smaller than the anodal, the former being placed stabile, over the upper cervical sympathetic ganglion of one side, the latter labile, on the opposite side of the vertebral spines, moving gradually downward, the session not exceeding three minutes. This is repeated daily or every alternate day.¹⁶⁹ It would prove a strong proof that this treatment really affected the morbid process in a remedial direction if any of the exact signs of the disease were to be modified by it, be it ever so slightly. If, after galvanization of the cervical cord and the sympathetic nerve, the initial myosis of tabes were temporarily lessened or the reflex contraction to light restored for ever so short a time, a brighter future would dawn for electro-therapeutics than seems now to be in store for it.¹⁷⁰

¹⁶⁹ Why, if the procedure be really remedial or efficiently palliative and devoid of evil consequences, it is not recommended to be repeated oftener I am at a loss to explain or understand. There are some factors involved in practical electro-therapeutic which it is scarcely possible to discuss without encroaching on delicate ground.

¹⁷⁰ In healthy persons the extent of the knee-jerk is increased by the spinal ascending galvanic current, and possibly this observation may lead to the establishment of a rational basis for its use in cases where the reflex is abolished or diminished.

Peripheral Treatment.—A number of therapeutical applications are made to the periphery where the symptoms of the sclerotic process are localized. The rationale of such applications is based on the assumption that peripheral conditions are capable of modifying the nutrition and functions of the cord. This is proven not alone by a host of observations made on the normal cord, but is also disastrously illustrated in the part played by surface chilling in the etiology of many acute and chronic diseases of the cord. Notwithstanding this latter, a large and influential body of German neurologists recommend cold baths and cold spinal douches in these affections. I have seen such excellent results from the use of warm baths that I am compelled to plead, in defence of my ignorance of the effect of cold ones, that I have never dared to use them. In numerous cases the beneficial effect of a warm bath is almost instantaneous. Warmth in any shape, whether atmospheric or in the shape of baths, is usually agreeable to patients suffering from the various forms of sclerosis. Cold, on the other hand, is disagreeable, aggravates the symptoms, and in many cases at least hastens the progress of the disease. A winter spent in the latitude of New York or Boston means so much ground lost by the patient, and a sojourn during the colder months in Southern California, New Mexico, Florida, or the West Indies enables the patient to avoid this loss. As regards the choice of climate and baths for sclerotic patients, I should be inclined to roughly formulate the indications as being identical with those of chronic rheumatism. The reaction against the use of warm baths in Germany, where they once were popular,¹⁷¹ is due to the employment of too high temperatures. Hot baths, in the strict sense of the term, including the various forms of vapor-bath, act badly. They increase instead of calming the irritative symptoms, as moderately warm baths do, and they entail too sudden a change in the bodily state. That, for the present, it is advisable not to adopt unreservedly either the extreme plan once in vogue or the equally extreme one which constitutes the reaction against it, is shown by the observations of Richter of Dalldorf, who records some discouraging results obtained by the use of cold baths in cases of tabes dorsalis. It is but necessary to refer to the fact that the lancinating pains of the latter disease, the rigidity of diffuse myelitis, and the spasms of lateral sclerosis are usually most severe in cold weather, and that the diseases mentioned appear to be rare in warm countries, to show the need of caution in using a therapeutical measure so similar in its action, even if it be but momentary and followed by a reaction, to those which provoke or aggravate the original disease. Eulenburg has seen five recoveries in tabes, and under such different plans of treatment that the latter is not credited by him with the good result. Three were treated with warm baths, one with cold baths, and one with nitrate of silver. It is seen here that the warm baths were used with good results more frequently than the cold.

¹⁷¹ The mud-baths of Cudowa in Gallicia had a very high reputation.

One of the most singular delusions of modern therapeusis—nerve-stretching—has, following the prediction made by several on both sides of the Atlantic, become obsolete. Introduced by Langenbuch, a surgeon, and attacking the disease at the sciatic nerve—a point where, as well-versed students knew, it was not located—the operation was looked upon with distrust from the beginning. The enthusiasm with which it was taken up by surgeons and by the interested portion of the laity—ever hopeful as tabic patients are of new drugs and methods of treatment—has led to a large number of trials, now numbering several hundred, and from which the useful lesson can be gathered that the good ripens slowly. Nerve-stretching in an organic disease of the spinal cord may take its place among the needless vivisections; it has not influenced the progress of a single case in any essential feature. On the contrary, it has more than once been directly responsible for acute myelitis, spinal hemorrhage,¹⁷² and pyæmia. In a number of cases reported by Langenbuch,¹⁷³ Benedict, Erlenmeyer, Schweminger, Debove, and W. J. Morton, the ataxia of the patient has been reported as relieved; in one case, exhibited by the latter operator before the American Neurological Association, this appeared quite evident, but not because the disease proper had been influenced, but for the same reason that prevents the development of marked ataxia in combined sclerosis. Just as the lateral-column lesion inhibits the ataxia which is due to the posterior-column lesion, so the motor paresis produced by stretching the sciatic nerves neutralizes the manifest features of the ataxic gait. As soon as the paresis is recovered from, the ataxia returns in its original form, unless, happily, one of the common spontaneous changes for the better occur. As a therapeutic procedure nerve-stretching is to-day properly limited to affections of the peripheral nerves.

¹⁷² Zacher, Archiv für Psychiatrie, xv. p. 430.

¹⁷³ Westphal showed after the autopsy of Langenbuch's first successful case that there had been no spinal lesion whatever.

One of the most useful peripheral remedies in the sclerotic processes is the faradic wire brush. It is both an anodyne and remedial for anæsthesia. A number of the tabic patients to whom I referred as not having deteriorated within long periods are provided with a portable faradic battery, and apply the brush to the spots affected by terebrating pains the moment these commence, obtaining instantaneous relief. As has been shown by Rumpf,¹⁷⁴ the cutaneous space-sense becomes more delicate in healthy and improved in tabic patients under its continued use. And while the inco-ordination of tabes is in part independent of the disturbance of cutaneous sensibility, yet if the latter can be refined the ataxic disturbance may be mitigated—a result occasionally obtained through the methodical use of the wire brush.

¹⁷⁴ Report of a discussion, Neurologisches Centralblatt, 1885, p. 526.

It is frequently found that sufferers from tabes dorsalis and other forms of sclerosis accompanied by ataxia walk much better in their stocking feet and in slippers than they do in the conventional street shoe or boot. The reason for this is obvious. The patient's gait is impaired by the disease, and, whether the ataxia be a pure co-ordinatory trouble or no, subjective uncertainty regarding contact with the ground which is experienced by most ataxic patients is an aggravating factor. Our modern foot-clothing, with its inflexible soles and raised heels, handicaps the patient as it were, depriving him of the use of what little tactile sensibility may be left him.¹⁷⁵ The use of low-heeled shoes with thin and flexible soles is therefore advantageous.

¹⁷⁵ The question whether tabes dorsalis is a disease of civilization has not been raised in any treatise I am acquainted with. Myelitis, both acute and chronic, occurs, however, rarely in the lower animals, as do also central dilatation of the cord and congenital defects of the latter. Posterior sclerosis I can find no record of in veterinary pathology. The influence of the repression of normal aids to locomotion by the foot-gear of civilized life as a possible predisposing factor in the etiology of ataxic troubles is a legitimate subject of inquiry. The lateness of the infant of civilized parents in acquiring the art of skilled locomotion may be in part, as philosophers claim, a penalty of exuberant development of the higher and inhibitive centres. But what part has the artificial obliteration of solar sensibility and pedal flexibility played in this inherited feature? What is its influence in establishing a pathological vulnerability?

The tremors of sclerotic affections, particularly those accompanying the disseminated forms, are from their distressing character prominent objects of special treatment. The bromides have been given with alleged good effect which I am unable to confirm. Curare has caused the tremor to disappear for two days in one of Erlenmeyer's patients. I have seen good results from the descending galvanic current applied in long sittings to the head and neck, sliding in to the point of tolerance, and sliding out before discontinuing. The mydriatics, atropine, and particularly hyoscyamin, often remove tremor radically for the time being; unfortunately, it is necessary to give them in almost toxic doses to obtain this effect. Recently, Feris recommended veratrum in doses of half a milligram repeated every four to five hours. It acted very well in every case in which I tried it, but, as it became necessary to increase the dose, the same objection was encountered as in the case of hyoscyamin. All these measures should be used as emergency remedies only; they cannot, in the nature of the case, prove curative, while their continued use produces a physiological indifference to their effect, and to that extent decreases their value as the case progresses.

MANAGEMENT OF SPECIAL SYMPTOMS AND COMPLICATIONS.—Among the most distressing features of many sclerotic affections is pain, which is usually associated with sleeplessness. The fulminating variety may be often relieved by the use of the actual cautery applied over the affected level of the cord and along the course of the nerve involved. But in the majority of cases morphine will have to be resorted to. Erb cautions against the use of this anodyne in cases where there is much reflex irritability of the cord, as morphine is said to increase this irritability when administered in small doses, and to reduce it again only when larger ones are administered. It is the latter alone which are serviceable with pain, and I have not yet seen any bad effects in the direction apprehended by Erb from such doses as it is necessary to give. That the physician administering it should be always on guard against the possible formation of a drug habit it is unnecessary to add. But it is also unnecessary to add what alternative he shall adopt when his choice lies between the lesser evil of the opium or morphine habit and the terrible martyrdom which some patients would be compelled to submit to if not allowed to indulge in it.¹⁷⁶ The evil effect of opium and its preparations on the visceral functions is to be neutralized, as far as possible, by the administration of laxatives and bitter tonics.

¹⁷⁶ Few sufferers from spinal disease use anodynes habitually; opium and its preparations are not fascinating to the majority of persons. On the other hand, there are two cases of tabes dorsalis now under my observation in which the patients have been compelled to use hypodermic injections of Magendie's solution for two and three years without any materially bad effect.

The deep-seated diffuse pains, such as are found in disseminated and diffuse sclerosis, are not as markedly relieved by opium as the terebrating and lightning-like variety. Frequently spastic or other signs of increased reflex excitability are associated with them; and as both are favorably influenced by the bromides, the latter are doubly indicated in such conditions.

With pains of a rheumatic character static electricity has been recommended. It undoubtedly relieves such pains, as skilfully-applied galvanism would. Its chief effects, it seemed to me from a six months' trial with it, are on the imagination and hopes of the patient.¹⁷⁷

¹⁷⁷ A large apparatus of the new and improved make was at my disposal at the nervous department of the Metropolitan Throat Hospital. It was very popular with sufferers from rheumatism, who had been allowed to accumulate in the class before I took charge, and with a paretic dement who suffered with the rheumatoid pains often found with diseases such as his.

The bromides and camphor¹⁷⁸ are recommended for the obstinate priapism found in some cases of early tabes and transverse myelitis. I have seen better results from warm hip-baths and general baths in this condition than from any drug. As a general rule, the exercise of the sexual function, where not already forbidden by the results of the disease, should be limited as much as possible. The frequency of normal seminal emissions in a given case is a guide to the amount of indulgence in this direction which may be permitted. Where there is the slightest indication of irritative or destructive lesions in the upper lumbar cord sexual acts should be entirely prohibited, for under these circumstances no greater injury could be done the weakened centres than to permit them. This is particularly noticed in those cases of tabes dorsalis which are marked by satyriasis in the early period.

¹⁷⁸ Particularly the monobromate of camphor.

The treatment of the bladder trouble and of bed-sores is carried out in the manner described in the section on Acute Myelitis. For bed-sores Hammond recommends the application of a stabile galvanic element consisting of a plate of silver and one of zinc, the two being united by a wire isolated in the usual way. The silver plate is laid on the bed-sore; the zinc plate, covered by a piece of moistened cloth, is laid on the unbroken skin somewhere in the neighborhood. The result is a weak current under whose stimulant effect the healing process takes place very rapidly. I have seen excellent results that had been obtained by this means in indolent ulcers of the leg. It does not, however, seem to have been tested with the malignant variety of bed-sore.

With regard to the management of muscular atrophies by electricity, massage, and strychnia, the same rules are to be followed which are laid down in the section on the Myopathic Atrophies. It is only to be specially remarked that few authorities encourage the administration of strychnia in sclerotic affections, and fewer still in such large doses as could be of any benefit in a wasting process.

Faradization of the affected eye-muscles is often useful in diplopia. The current may be applied by means of a cup-shaped eye-electrode, or, better, by using a finger as an electrode.

The moral management of sufferers from sclerotic spinal affections is very important. The popular notion about spinal disease generally is such that the announcement made to a patient that he is suffering from any form of it is as alarming as would be the discovery of a tumor in his brain or a cancer in his stomach, and exerts a depressing effect. This it should be sought to avoid. A large number of sufferers from sclerosis live longer and suffer less than a portion of those afflicted with rheumatic and gouty affections; and the physician is justified in obtaining the desirable effect which a hopeful or resigned state of the mind undoubtedly has on the body, by laying great stress on this undeniable fact.