DISEASES OF THE MEMBRANES OF THE BRAIN AND SPINAL CORD.
BY FRANCIS MINOT, M.D.
The membranes or envelopes of the brain and cord were formerly reckoned as three in number: the dura mater, lying next to the inner surface of the bones of the cranium and spinal column, forming an internal periosteum; the pia mater, which is in immediate contact with the brain and cord; and the arachnoid, which was described as a distinct membrane loosely attached to the pia mater, but more firmly united to the dura, and constituting a closed sac or serous cavity called the cavity of the arachnoid. This view is now abandoned by most anatomists, who regard the external arachnoid as simply a pavement epithelium covering the internal surface of the dura, and the visceral arachnoid as constituting the external layer of the pia. The term cavity of the arachnoid has, however, been generally retained for the sake of convenience; and it gives rise to no obscurity if we remember that by it we simply mean the space between the dura and the pia.
The diseases of the membranes which I shall consider are—congestion and inflammation of the dura, including hæmatoma; congestion and simple and tubercular inflammation of the pia; and meningeal apoplexy.
The membranes of the brain and those of the cord may be separately diseased, or both may be affected at the same time. Simultaneous inflammation of the cerebral and spinal meninges is apt to occur epidemically, and is supposed to be zymotic in its origin. This is described in another article. (See EPIDEMIC CEREBRO-SPINAL MENINGITIS, Vol. I. p. 795.)
Inflammation of the Dura Mater of the Brain.
SYNONYM.—Pachymeningitis. Either surface of the dura may be inflamed separately, and in many cases the symptoms are sufficiently definite to render it possible to diagnosticate the situation of the disease in this respect during life, especially when taken in connection with the causes. For this reason it is usual to speak of external and internal pachymeningitis. A peculiar form of the latter is accompanied by the effusion of blood upon the arachnoidal surface, which sometimes forms a tumor called hæmatoma. Congestion is also sometimes included in the diseases of the dura mater, but is rarely alluded to by writers on pathology or clinical medicine.
Congestion of the Dura Mater.
Except as the first stage of inflammation, congestion of the dura can hardly exist unless in connection with the same condition of the pia or of the brain. Its causes are either local, such as thrombosis of the sinuses, syphilitic or other growths in the membranes; or remote, the principal being obstructions to the general circulation, including valvular disease of the heart, emphysema and other affections of the lungs, renal disease, compression of the superior cava or jugulars by aneurism and other tumors, delayed or suppressed menstruation, etc. The symptoms cannot be distinguished from those of congestion of the pia or of the brain—namely, headache, a sensation of throbbing, pressure, or weight in the head, somnolence, etc. The absence of fever would serve to distinguish the affection from an inflammatory condition of the membranes or brain.
Inflammation of the External Surface of the Dura.
SYNONYM.—External pachymeningitis.
ETIOLOGY.—The most frequent causes of external pachymeningitis are injuries to the cranial bones from violence, caries and necrosis of the same, and concussion from blows on the head. Next in order of frequency, if not even more common, comes the propagation of inflammation from disease of the inner ear and of the mastoid cells. It is only of late years that this important subject has been brought prominently forward and the danger of ear diseases in this respect fully pointed out. The channels of communication, as indicated by Von Tröltsch1 in his valuable article on diseases of the ear, are along the arteries and veins which pass from the skin of the meatus and the mucous periosteal lining of the middle ear to the contiguous bone, while the capillaries of the petrous bone are in direct connection with the dura mater, so that the vessels of the latter are in communication with the soft parts of the external and middle ear. The vessels of the ear and the membranes of the brain are also directly connected through the diploëtic veins of the temporal bone, which discharge into the sinuses of the dura, as well as through the venæ emissariæ, which, arising from the sinuses, pass through the bone and discharge their contents into the external veins of the head. Von Tröltsch also points out that the extension of an inflammatory process may occur along the sheath of the facial nerve, the canal of which (canalis Fallopii) is a branch of the internal auditory canal and is lined by the dura mater. The latter is separated from the mucosa of the tympanum only by a thin, transparent, and often defective plate of bone. Inflammation may also be transmitted from the scalp by means of the vessels which pass through the bones of the skull. In this way erysipelas and other diseases of the integument sometimes give rise to external pachymeningitis.
1 “Die Krankheiten des Gehörorganes,” von Anton von Tröltsch, in Gerhardt's Handb. der Kinderkrankheiten, Tübingen, 1879, 5 B., ii. Abt., p. 150; also English translation of the same, by J. O. Green, M.D., New York, 1882, p. 107.
SYMPTOMS.—There are no known symptoms which are characteristic of inflammation of the external surface of the dura. In cases of death from other diseases an autopsy may show traces of previous inflammation, such as thickening of the membrane and its firm adhesion to the cranial bones, which were not manifested during life by other symptoms than those which accompany meningeal disease in general; and in some instances none at all were known to have occurred. At a variable time after the receipt of an injury to the head the patient may complain of headache, followed by a chill, with high fever, vomiting, vertigo, delirium, unconsciousness, convulsions, etc., arising from compression by the products of inflammation. The same phenomena may follow the transmission of inflammation to the dura from caries or other disease of the bones, or from otitis medea purulenta. These symptoms usually continue without interruption, though there is sometimes more or less complete remission of the pain, and the patient may recover his consciousness for a time, thus giving rise to fallacious hopes. In a large proportion of cases the disease extends to the inner surface of the membrane and to the pia, without any noticeable change in his condition other than coma. In chronic external pachymeningitis the principal symptom is pain in the head, which may persist for weeks or months without other manifestations except drowsiness. Sometimes, on the contrary, there is obstinate vigilance. Mental symptoms, such as loss of memory, hallucinations, dementia, or mania, are sometimes noticed, ending, as in the acute form, in coma.
PATHOLOGICAL ANATOMY.—In chronic cases often nothing is found but thickening of the membrane, which generally becomes firmly united to the inner surface of the cranium. Indeed, these appearances are not unfrequently observed, to a limited extent, when there has been no history of disease to account for them. In other chronic cases the connective tissue of the membrane is found to be in part ossified, and the osteophytes of the cranium sometimes found in pregnant women and in patients with rheumatic cachexia are supposed to be due to a chronic inflammatory process of the dura. The first changes observed in acute external pachymeningitis are increased vascularization, shown by red lines corresponding to the blood-vessels, with punctiform extravasations, swelling, and softening of the tissue. Later, there is thickening of the membrane from new formation of connective tissue, and exudation of lymph, and sometimes of pus, which latter may accumulate between the dura and the cranial bones, or in traumatic cases may escape through openings in the skull. The dura and the pia become united in most cases of acute inflammation. The lateral sinuses frequently contain thrombi, which, when ante-mortem, are firm in structure, reddish-brown in color, often closely adherent to the walls of the vessel, and may extend to other veins, sometimes reaching as far as the jugulars. When purulent inflammation of a sinus occurs, its walls are thickened, softened, and discolored, and the inner surface is roughened. The thrombus becomes more or less purulent or sanious, disintegrates, and the infecting particles are carried into the circulation, giving rise to embolism and disseminated abscesses of the lungs, kidneys, liver, or spleen. Other lesions, such as injury or caries of the cranial bones and purulent inflammation of the middle ear and of the mastoid cells, are frequently found in conjunction with pachymeningitis, to which they have given rise. When the disease of the dura extends to the pia, the adjacent portion of the brain is often found implicated in the inflammation. In traumatic cases the dura may be detached from the bone and lacerated to a greater or less extent.
DIAGNOSIS.—The existence of external pachymeningitis may be suspected from cerebral symptoms following traumatic injury of the skull, erysipelas, or suppurative otitis medea, but apart from the etiology it would not be possible to distinguish it from internal inflammation of the membrane, or even from leptomeningitis.
PROGNOSIS.—In cases of suspected external pachymeningitis the prognosis will depend upon the evidence of effusion of pus or blood between the dura and the skull, and the possibility of their removal. A large proportion of cases are fatal, especially those arising from caries of the cranial bones and from the propagation of disease from the middle ear, the mastoid process, or the external surface of the skull, the inflammation extending through the membrane to the arachnoid surface of the dura, and also to the pia mater. This would be shown by a high temperature, rapid pulse, pain, and delirium, followed by coma and perhaps convulsions. The frequency with which external pachymeningitis occurs in connection with diseases of the ear should put the physician on his guard in cases of otorrhœa or pain in the ear, that he may warn the patient or his friends of the possibility of danger, and may employ an appropriate treatment.
TREATMENT.—In all cases of injury to the skull or of severe concussion the possibility of subsequent external meningitis should be borne in mind. The patient should be confined to the bed and be carefully secluded from excitement. Cold applications should be made to the head, the diet should be simple and somewhat restricted, and the bowels kept free without active purging. If there be evidence or suspicion of the presence of pus or of blood between the dura and the skull, means should be taken to evacuate the effusion. In case of inflammatory symptoms leeches should be applied behind the ears, and a stimulating liniment or croton oil rubbed on the scalp. There is no specific treatment. Pain and sleeplessness must be relieved by opiates and sedatives, and the strength must be sustained by nourishing diet and stimulants.
Internal Pachymeningitis.
Internal pachymeningitis is of two kinds: 1st, simple inflammation, which may be accompanied by purulent exudation and by a corresponding affection of the pia mater: 2d, hemorrhagic inflammation or hæmatoma of the dura mater. Simple inflammation of the internal or lower surface of the dura, without the coexistence of external pachymeningitis is rarely found in the adult. The morbid appearances differ but little from that of the external form, and the causes and the diagnosis are also similar. In children, however, it is not uncommon, according to Steffen.2 The pus may discharge itself spontaneously through the fontanels or the sutures, or caries of the cranial bones may open a passage for its exit. It has also been evacuated artificially when the symptoms have indicated its presence. In other cases more or less extensive firm adhesions between the dura and pia mater have shown the previous existence of inflammation, but it would be difficult to say in which membrane it began. In some instances no symptoms are observed during life; in others the coexistence of inflammation of the pia, effusion into the ventricles, etc. prevent an exact diagnosis.
2 “Die Krankheiten des Gehirns in Kindesalter,” von Dr. A. Steffen, in Gerhardt's Handb., 5 B., i. Abt., 2te Hälfte, p. 380.
The TREATMENT does not differ from that of inflammation of the external layer of the pia.
Hæmatoma of the Dura Mater.
SYNONYM.—Hemorrhagic pachymeningitis.
DEFINITION.—A chronic inflammation of the dura mater, resulting in the formation upon its inner surface of successive layers of false membrane, into and between which there is usually an effusion of blood, the whole sometimes forming a large solid mass between the dura and the cavity of the arachnoid.
ETIOLOGY.—Hemorrhagic pachymeningitis never occurs in healthy persons except from traumatic causes. It is most frequently observed in advanced life, and especially in the male sex. In a large number of cases the blood is in an unhealthy condition, and hence the disease is seen in alcoholism, in scurvy, in acute articular rheumatism, and in the acute febrile affections, as typhoid fever, pleuro-pneumonia, and pernicious anæmia, of which last, according to Huguenin,3 it complicates one-third of the cases. It is frequent among the chronic insane. It is occasionally met with in young children, but with them its causes are mostly unknown; according to Steffen,4 they may consist in alterations of the blood resulting from insufficient nourishment or from the infectious diseases, and from abnormal blood-pressure, as in whooping cough, asthma, etc., as well as from blows on the head.
3 G. Huguenin, “Acute and Chronic Inflammations of the Brain,” in Ziemssen's Encylop., Am. translation, New York, 1877, vol. xii. p. 401 et seq.
4 Op. cit., p. 386.
SYMPTOMS.—Many cases of hemorrhagic pachymeningitis complicating other cerebral diseases can be distinguished by no special symptom from the original malady. Thus, in cases of chronic insanity its existence may not be suspected during the lifetime of the patient. Steffen quotes5 the case, reported by Moses, of a child seven months old who died of catarrhal pneumonia, and who exhibited no symptom which could suggest any disease of the brain or its membranes. The autopsy revealed a pachymeningitic cyst extending over the anterior half of the right hemisphere. When symptoms are present they vary in different cases according to the acuteness of the inflammatory process, the amount and situation of the effusion, and the participation of the pia mater and brain in the disease. In the beginning they are usually indefinite, headache being the most common and often the only complaint. This may continue for weeks without any other indication of disease, but it is frequently accompanied by tinnitus aurium, vertigo, muscular weakness, and contraction of the pupils. Wakefulness and restlessness at night and slight twitching of the facial muscles or of the limbs sometimes occur. There may be no change in the condition of the patient for a considerable length of time (weeks or months), or he may improve to some extent, owing to the absorption of the serous portion of the effusion or to the tolerance of the foreign body acquired by the brain. Sooner or later a fresh hemorrhage is followed by a recurrence, and usually an aggravation, of all the symptoms. Sometimes the patient becomes comatose, and dies speedily with apoplectic symptoms, but this is not common at an early period. The extravasation of blood generally takes place in small quantities at a time, without giving rise to unconsciousness or paralysis. After a period of uncertain duration, when the tumor has attained considerable dimensions a condition of somnolence may take place, the patient sometimes sleeping twenty-four hours or longer at a time. Distinct paralysis rarely occurs, though hemiplegia is sometimes seen, and the paralysis has been observed on the same side with the lesion. When symptoms of compression appear the pupils become dilated. Toward the end of life the patient is usually in a state of profound coma, the pulse is slow and irregular, and the sphincters are relaxed.
5 Op. cit., p. 394.
The distinctive features of internal pachymeningitis, therefore, so far as they are at present known, are those which would depend upon a primary cerebral irritation, followed by those of compression of the brain—persistent, often severe, headache, with contracted pupils, and occasionally motor and sensory disturbances; afterward, coma, dilated pupils, and involuntary discharges from the bowels and bladder.
The DURATION of the disease is exceedingly variable, extending from a few days to more than a year. According to a table made from carefully observed cases by Huguenin, 74 per cent. of patients die within thirty days; 18 per cent. live from one to six months; 4 per cent. live from six months to one year; and 4 per cent. live over one year.
PATHOLOGY.—A difference of opinion has existed among pathologists concerning the true nature of hemorrhagic effusions of the inner surface of the dura mater, especially as to whether the membrane in which they are enclosed is formed by a deposit of fibrin from the effused blood itself, or whether the disease consists essentially in an inflammation of the dura, followed by a pseudo-membranous deposit into which blood is afterward extravasated. The latter explanation, offered by Virchow, has been generally accepted, but Huguenin, whose opportunities for observing the disease were unusually good, believes that the first stage of hæmatoma is not the formation of connective tissue, but simply an extravasation of blood.
The disease begins with hyperæmia of the dura mater in the area of distribution of the middle meningeal artery, followed by the formation upon its inner surface of an extremely delicate membrane in small patches of a yellowish color and studded with innumerable bloody points. If the membrane be carefully raised, it is found to be connected with the dura by very delicate blood-vessels, and to contain an immense number of very wide and thin-walled vessels, much larger than ordinary capillaries.6 At a later stage we find the membranes to be made up of several distinct layers, of which the innermost exhibits the character of the primary deposit, being thin and abundantly supplied with blood-vessels, while those of older formation have become successively thicker and are composed of tough, lustrous fibres of connective tissue almost as dense as that of the dura mater itself. The delicate structure of the false membranes and of the vessels which they contain leads almost inevitably to the effusion of blood, which increases in quantity with the thickness of the whole growth, so that in an advanced stage it is not uncommon to find large pools of blood, partly clotted and partly fluid, constituting what is called hæmatoma of the dura mater. The small bloody points are within the substance of the false membrane; the extravasations are interstitial, the largest being always found between the youngest membrane and the older layers. In some cases serous transudations also occur between the false membranes. In still rarer instances no blood or serum is found between or beneath the layers. Occasionally small quantities of blood escape by leakage through the delicate membrane into the cavity of the arachnoid.
6 See Rindfleisch's Manual of Pathological Histology, New Sydenham Soc.'s translation, 1873, vol. ii. p. 302.
The usual situation of internal pachymeningitis is the vault of the cranium, near the median line, the upper or external layer of the tumor being in relation with the dura mater, to which it is adherent, and the lower or internal with the arachnoid and pia mater. If the effusion be extensive, it spreads downward over the frontal and occipital lobes of the brain, and laterally toward the fissure of Sylvius. In the majority of cases the disease occupies both sides of the median line symmetrically, but it may be limited to one side only. According to Huguenin, 56 per cent. of the cases embrace the surfaces of both hemispheres; 44 per cent., that of one only. Hæmatoma very rarely occupies the base of the cranium. The thickness and consistency of the deposit vary in different cases, depending upon the number of successive exudations, and hence are most marked in cases of the longest duration.
Hemorrhagic pachymeningitis is occasionally met with in young children, but much more rarely than in adults. The disease is usually more acute than in older persons, but the anatomical appearances are essentially the same.7
7 For an able description of the lesions of hemorrhagic pachymeningitis in children see the third edition of Rilliet and Barthez's Maladies des Enfants, by Barthez and Sanné, Paris, 1884, vol. i. p. 152.
PROGNOSIS.—The great majority of cases end fatally. A few instances of recovery are reported in which the diagnosis seems justified by the symptoms. Moreover, it is not very rare to find, on post-mortem examination of those who have died of other diseases, evidence of the former existence of hemorrhagic pachymeningitis. According to Steffen, while the prognosis of simple pachymeningitis in children is frequently good, owing to the favorable conditions for the exit of pus through the open fontanels and sutures, in hemorrhagic pachymeningitis recovery is rare.
DIAGNOSIS.—In a disease whose symptoms are so vague the diagnosis must of necessity be difficult and often impossible. The chief elements for the formation of the diagnosis are the slow and interrupted progress of the affection, persistent headache, tendency to prolonged slumber, and final coma; the absence of paralysis of the cranial nerves, of vomiting, and of general convulsions; the age of the patient, the coexistence of alcoholism, chronic insanity, or acute rheumatism, and traumatism. The diseases for which hæmatoma would be most likely mistaken are acute inflammation of the meninges, apoplexy from cerebral hemorrhage, tumor in the substance of the brain, and necrobiosis from thrombus or embolus. The absence of symptoms characteristic of these affections might lead to a probable diagnosis by exclusion, but in many cases the existence of the disease cannot be determined with certainty. In children it is most likely to be confounded with tubercular meningitis, from which it may be distinguished by the fact that it is most common under the age of two years, the other being rare before that period, and that the characteristic symptoms of tubercular meningitis (prodromic period, vomiting, irregularity of pulse, etc.) are wanting. But the tubercular disease in young infants may closely resemble hæmatoma, a profound coma replacing all other symptoms. Here the existence of tuberculous disease in the parents or other near relatives would point strongly to tubercular meningitis, while the absence of such antecedents would suggest hæmatoma.
TREATMENT.—If the disease be a complication of alcoholism, anæmia, scurvy, rheumatism, etc., the treatment appropriate to those affections should be employed, along with remedies addressed to the local disease. For the early symptoms of irritation, perfect rest in bed, cold to the head, bromide of potassium internally, sinapisms to the back of the neck, together with simple and nutritious diet, are the most efficient means. The bowels must be regulated, but purging is not necessary. The abstraction of blood from the head by leeches to the temples or behind the ears, or by cupping, is recommended by most authorities, especially if there be much heat of the head. Mercury may be tried, care being taken not to salivate the patient. It is obvious that this treatment, in order to be of any avail, must be instituted at the earliest stage of the disease. After the probable formation of the hæmatoma an effort should be made to promote its absorption, which sometimes actually takes place, as is proved by the autopsies of patients who, having previously suffered from this affection, have died from other causes. The iodide of potassium or the iodide of sodium should be employed perseveringly for this purpose, in the dose of from ten to thirty grains three times daily. The bromide should also be continued if necessary. The acne which sometimes accompanies the continued use of these remedies may be prevented or cured by the use of three to five drops of the liquor potassæ arsenitis, given once or twice daily after meals. Counter-irritation to the scalp by means of stimulating liniments or croton oil, and small blisters to the temples, are likely to do good. In alcoholic subjects the amount of wine or spirit taken should be regulated by allowing enough to support the strength, without too suddenly withdrawing the accustomed stimulant. In the stage of coma the treatment must be purely expectant. The state of the bladder must be regularly examined, and the catheter employed when necessary. Liquid nourishment should be carefully given as long as the patient is able to swallow.
Cerebral Meningeal Hemorrhage.
SYNONYM.—Meningeal apoplexy of the brain. Hemorrhage of or upon the membranes of the brain is closely connected with intracerebral hemorrhage. Both arise from similar causes, and the former may result directly from the latter. It is for convenience of arrangement that the two subjects are treated separately in this work.
ETIOLOGY.—The causes of meningeal apoplexy are predisposing and immediate. The most important predisposing cause consists in disease of the cerebral vessels, especially the arteries, which favors the formation of so-called miliary aneurisms, as demonstrated by Charcot and Bouchard in the case of cerebral apoplexy. Disease of the vessels in its turn arises from various conditions, among which alcoholism in adults holds a prominent place from its tendency to favor a fatty degeneration of the vascular walls. In subjects of purpura or hæmophilia (the so-called bleeders), in whom, from an inherent weakness of the capillary vessels or a deficiency of the fibrin of the blood, or both combined, there is a tendency to extravasation of the blood in various parts, hemorrhage into the arachnoid cavity may occur.8 A new-born child under my observation had bleeding at the navel and ecchymoses in various parts of the body. Suddenly it became comatose, and it died with signs of cerebral compression. There was no autopsy, but it seems probable that hemorrhage into the cavity of the arachnoid had taken place. A sister of the patient had also had spontaneous hemorrhage from the navel and from other parts shortly after birth, but recovered. Chronic general arthritis and gout also probably predispose to the affection, as well as old age, which is accompanied by atrophy of all the tissues. The disease is most frequently met with in the two extremes of life; according to Durand-Fardel,9 in adults the largest number of cases occurs between the ages of seventy and eighty years.
8 A case of this kind is cited in the article “Pathologie des Méninges” in Nouv. Dict. de Méd. et de Chirurg. pratiques, Paris, 1876, vol. xxii. p. 101.
9 Traité clinique et pratique des Maladies des Vieillards, par M. Durand-Fardel, Paris, 1854, p. 283.
The exciting causes comprise injuries to the head, both with and without fracture; strong muscular effort, as in lifting, straining at stool or in labor; powerful action of the heart in cases of hypertrophy. An interesting case is reported10 by S. G. Webber of Boston, in which the effusion was evidently caused by vomiting; a clot of blood covered the greater part of the posterior two-thirds of the right hemisphere. Sometimes meningeal hemorrhage may arise from the bursting of an intracerebral apoplexy into the arachnoid cavity, as in a remarkable case occurring in the practice of Morris Longstreth of Philadelphia, of bilateral effusion.11 Outside the dura, corresponding with the left middle cerebral lobe, was a considerable amount of blood connected with a fracture of the skull, and on the right side a large quantity of blood in the cavity of the arachnoid, originating in the middle lobe, which was torn up. The patient had fallen in the street; he was stupid, there was no paralysis, active delirium came on, followed by coma and death in twenty-four hours. Here was cerebral apoplexy bursting into the cavity of the arachnoid on the right side, and causing the fall, which was the occasion of the fracture and hemorrhage on the left side.
10 Boston Med. and Surg. Journal, Jan. 17, 1884.
11 Ibid., Dec. 28, 1882.
In young children, especially in the new-born, meningeal hemorrhage may follow difficult and instrumental labor, either from injury to the skull or from delay in the establishment of respiration, as in breech presentation, though it sometimes occurs in cases in which the labor has been normal. In a case of breech presentation under my care in 1873 the child, a female weighing nine pounds, did not cry or breathe for some minutes after birth, although delivery had not been much delayed. Soon afterward it was noticed that it did not move the right arm, although it moved the hand and the fingers. In the course of twenty-four hours, during which time it cried much more than usual, it became comatose, and remained so until its death, three days after birth. The whole surface was livid, and the child had two or three short convulsions. At the autopsy a clot about the size of a grape was found in the pia mater on the upper surface of the cerebellum, in the immediate vicinity of the pons Varolii. The brain was so soft that the amount of injury received by the cerebellum could not be exactly ascertained, but it was probable that the clot extended into the fourth ventricle.
Thrombus of the sinuses of the dura mater, and less frequently of the cerebral arteries, is the origin, in a considerable number of cases, of meningeal hemorrhage in children, in consequence of pressure upon the delicate vessels of the membranes caused by the obstructed circulation. Bouchut12 reports an observation of hemorrhage produced in this way.
12 E. Bouchut, Clinique de l'Hôpital des Enfants maladies, Paris, 1884, p. 263. See, also, Steffen, op. cit., p. 352.
SYMPTOMS.—In some cases the attack is preceded by indications of congestion, such as headache, vertigo, staggering, confusion of ideas, noises in the ears, feeling of weight in the head, delirium, stupor. At the time of the attack the patient frequently complains of severe pain in the head, just as in cerebral hemorrhage, and then falls to the ground with complete loss of consciousness. Sometimes the symptoms come on gradually. Hemiplegia occurs in a notable proportion of cases. Convulsions may occur at any time after the attack. In Webber's case, already referred to, the first symptom was sharp pain in the head and neck; this was followed by very severe headache and pain on motion of the head. Intelligence gradually diminished; on the sixth day there was almost no consciousness, and the patient died in about eight days. She had occasional spasms, in which both eyes were turned toward the left in extreme conjugate deviation, and the left side of the face was distorted. The spasms were followed by suspension of respiration for nearly a minute, cyanosis, and paralysis of the left hand and leg. Both the nature of the lesion and its seat were correctly diagnosticated during the patient's lifetime.
As a rule, the condition of unconsciousness continues up to the time of death, but in some cases there are intermissions during which the patient responds to questions more or less promptly. Death takes place at a period varying between a few hours and several days. Durand-Fardel13 reports a case in which the patient lived a month from the first attack, with preservation of the intellect and of motion. An inmate of the Home for Aged Women in Boston, eighty-eight years old, previously in good health, complained of severe pain in the head one morning before rising. She took her breakfast in bed, and immediately afterward vomited copiously. From that moment she became insensible, and remained so until her death, seven days and three hours afterward. During this time there was no stertor. No decided paralysis could be discovered, but there was some rigidity of the left arm. At the autopsy an effusion of blood was found in the arachnoid cavity extending from below upward on each side to a level with the top of the ear. There was a large amount of blood at the base of the brain, and both lateral ventricles were distended with bloody serum. The vessels were generally in an atheromatous condition. There was no laceration of the brain. The source of the hemorrhage could not be ascertained. In such a case the condition of the patient in respect to power of movement often cannot be ascertained with certainty, in consequence of the abolition of consciousness. Complete muscular resolution is most common when the effusion is bilateral, but when the hemorrhage is limited to one side more or less paralysis of the opposite limbs may exist. Should the blood make its way into the spinal canal, it might give rise to special symptoms, but this is not probable in view of the large amount of the cerebral effusion under the circumstances, which would produce complete insensibility or speedily cause death by pressure on the medulla.
13 Op. cit., p. 202.
The temperature of the body immediately after a copious cerebral or meningeal hemorrhage falls below the normal point, and remains so for several hours, after which it rises, its degree varying according to circumstances. In fatal cases the elevation is extreme, and remains so until death. If the patient recover, it gradually returns to the normal standard.
Vomiting is a frequent symptom at the beginning of the attack, just as in intracerebral hemorrhage, owing probably to compression of the pneumogastric by the effusion at the base of the brain. In Webber's case the vomiting was evidently the cause of the hemorrhage, and not its consequence, since it had been a frequent symptom for several days before the attack, and was probably due to the presence of a calculus in the pelvis of the right kidney, which was found at the autopsy, and there was no blood at the base of the brain.
PATHOLOGICAL ANATOMY.—The chief points of interest in the morbid anatomy relate to the seat and source of the effusion, the amount and condition of the blood, the state of the vessels and that of the brain, including the ventricles. In respect to the seat, the hemorrhage may occupy the space between the cranial bones and the dura mater; it may be found on the lower surface of the latter, in the arachnoid cavity, or in the meshes of the pia mater, the so-called subarachnoid space. Blood found upon the outer surface of the dura, between that membrane and the bones, is almost always the result of traumatic causes, such as blows or other injuries, with or without fracture, or of caries of the skull. If below the dura, but between that and the so-called parietal layer of the arachnoid, the lesion comes under the title of pachymeningitis interna, already described as an inflammatory disease of the dura with hemorrhagic effusion. The arachnoid cavity and meshes of the pia are by far the most common situations in which the blood is found in meningeal hemorrhage. The origin of the effusion is either the rupture of a capillary aneurism of one of the arterioles of the membrane or of one of the vessels themselves in consequence of atheromatous or other degenerations of its walls. On account of the minute size of the vessels it is seldom possible to discover the exact point at which the rupture took place. In rare instances the source of the hemorrhage is within the brain, the blood being forced through the cerebral tissue, either into the meshes of the pia or upon the surface of that membrane. The amount of hemorrhage varies according to conditions which are mostly unknown, but is probably dependent upon the size of the ruptured vessel and the conditions under which the accident occurs, such as muscular effort, cardiac action, etc. In some cases it is so small as to give rise to no definite symptoms, as is evident from post-mortem examinations of those who have died from other causes. In these cases there may be either a single effusion or several. The amount is largest when the arachnoid cavity is the seat of the extravasation. The blood, which may be either liquid or more or less coagulated, according to the time which has elapsed since the hemorrhage, is usually found upon the convexity of the hemispheres, most frequently on one side only, and oftenest on the left. But if the rupture have taken place at the base, it often ascends on each side, as in a case mentioned above. Where a large vessel has given way, its contents may cover a great part of the surface of the brain. The coagulum is found in a thin layer, which at the end of a few days is covered with a transparent envelope, evidently composed of a deposit or separation of fibrin. Should the patient survive long enough, this membrane may become organized, receiving vessels from the adjacent pia, and in turn become the seat of new hemorrhages, exactly as in the hæmatoma of internal pachymeningitis. In cases in which absorption of most of the fluid part of the effusion takes place, the membrane remains more or less dense and vascular, and usually contains a small quantity of recently-effused blood within its meshes. Small cysts, containing transparent or reddish-brown serum, are also occasionally observed enclosed between the layers of the membrane. In very young children, whose fontanels are not yet ossified, these cysts sometimes attain to a large size, containing several pints of fluid, which is more or less limpid from absorption of the coloring matter of the blood, constituting the so-called dropsy of the arachnoid.14 The convolutions of the brain are more or less flattened according to the amount of the effusion, and the cortical substance is correspondingly anæmic from pressure. The blood may make its way, if extravasated in large quantities, into the ventricles, over the medulla, into the spinal arachnoid cavity, or even into the central canal of the spinal cord. The arteries of the brain, especially at the base, are frequently in a state of atheromatous degeneration, and thrombi often occupy the sinuses of the dura mater.
14 Charles West, M.D., Lectures on the Diseases of Childhood and Infancy, 6th ed., London, 1874, p. 62. These large cysts are much more frequently (perhaps solely) found in cases of hemorrhagic pachymeningitis. (See Barthez and Sanné, op. cit., vol. i. p. 157.)
DIAGNOSIS.—The distinction between meningeal hemorrhage and cerebral apoplexy is always difficult, and in the majority of cases impossible. Sudden pain in the head, vomiting, and lowering of the bodily temperature (the thermometer should be placed in the rectum), followed by loss of consciousness, are strongly suggestive of hemorrhage within the cranium, either cerebral or meningeal. If these symptoms are followed by coma and resolution without obvious paralysis, the diagnosis would be almost impossible between intra- and extra-cerebral extravasation. If the loss of consciousness be not complete, so that the presence or absence of paralysis can be ascertained, we can sometimes distinguish the situation of the hemorrhage. Right-sided hemiplegia, with paralysis of the face or tongue, or with aphasia, is most probably owing to hemorrhage or embolism somewhere in the left motor tract, and hence within the brain. If the absence of paralysis can be certainly ascertained, the probabilities are in favor of meningeal apoplexy. Convulsions affecting the face or limbs of one side would point to irritation of the cortical centres of those parts, and so far to extravasation on the surface of the brain (on the opposite side), as in Webber's case. Where the amount of hemorrhage is small it furnishes no diagnostic indications. In the case of new-born children the presumption is in favor of meningeal effusion.
PROGNOSIS.—If the effusion be considerable in amount, as indicated by prolonged coma with resolution, the issue is almost inevitably fatal, though life is occasionally prolonged for a surprising length of time. Slight hemorrhages are doubtless recovered from, but there are no means for their certain diagnosis.
TREATMENT.—The treatment, which is essentially the same as that for cerebral congestion, has for its object the arrest of the hemorrhage, and, if that can be effected, the absorption of the effused blood. In view of the former, the patient's head should be elevated and kept cool by the application of ice. Unless the bowels have previously been freely moved, saline laxatives, followed by enemata if necessary, must be given. The state of the bladder must be carefully attended to. Liquid nourishment alone, in moderate quantities at regular intervals, is permissible, with stimulants if there be signs of exhaustion. For the absorption of the effusion mild counter-irritation to the scalp and the administration of the iodide of potassium may be employed.
Congestion of the Cerebral Pia Mater.
The pia mater consists of two layers, separated by a loose connective tissue. The outer layer, being that which was formerly called the visceral layer of the arachnoid, is stretched smoothly over the convolutions of the brain without dipping into the sulci; the inner layer is closely connected with the surface of the brain, whose inequalities it follows. The two layers are more firmly united together over the convolutions than between them; in the latter situation the connection is loose, and the space which separates the surfaces is called the meshes of the pia. The membrane extends into the ventricles, investing the ependyma and the choroid plexuses, and over the medulla oblongata and spinal cord. In the normal condition it is loosely attached to the brain, from which it can be stripped off without loss of substance. The meshes of the pia, together with the ventricles, constitute a series of cavities connected with each other, containing a variable amount of cerebro-spinal fluid, and they communicate with the lymph-spaces surrounding the blood-vessels. Pressure within the cranial cavity, from congestion of the vessels or from the products of inflammation, is thus relieved in a measure by displacement of the cerebro-spinal fluid, which is driven out through the perivascular lymph-spaces.
Congestion or hyperæmia of the pia mater probably never occurs independently of that of the external surface of the brain, on account of the intimate vascular connection of the two. In the adult it can only exist to a limited extent, on account of the unyielding nature of the cranial walls and of the limited compensatory action of the cerebro-spinal fluid. In young children the incomplete ossification of the skull and the delicate structure of the vessels are more favorable to congestion.
ETIOLOGY.—The causes of hyperæmia of the pia mater are in the main the same as those of congestion of the dura.
SYMPTOMS.—Since congestion of the pia always coexists with that of the corresponding part of the external portion of the brain, it is impossible to separate the symptoms belonging to each. They are therefore usually included under the head of Cerebral Congestion, to which article the reader is referred.
PATHOLOGICAL ANATOMY.—Arterial hyperæmia of the pia is seldom discovered after death, the elasticity of the vessels causing transudation of the fluid part of the blood through their walls. Venous congestion of the pia is more frequently noticed, usually in connection with that of the dura, the sinuses with their accompanying veins being distended with blood, and in cases of long standing often containing thrombi. Simple hyperæmia of the pia being rarely or never fatal of itself, these appearances are usually accompanied by those of inflammation of the membrane or of the cortical layer of the brain (effusion of lymph or pus), or by hemorrhage.
TREATMENT.—In a case of suspected congestion of the pia the treatment would be the same as that of cerebral congestion.
Inflammation of the Cerebral Pia Mater.
SYNONYMS.—Meningitis, Leptomeningitis, Acute non-tubercular hydrocephalus.
Meningitis (by which is generally understood inflammation of the pia) appears under an acute, a chronic, and an epidemic form. The latter, being a zymotic disease, is described in a separate article, to which the reader is referred.
ETIOLOGY.—Meningitis occurs both as a primitive disease and as secondary to other affections. The former is rare, the latter is more frequent. The causes of idiopathic meningitis are for the most part unknown. Exposure to the sun's rays and excessive indulgence in alcoholic liquors are thought to excite it in some instances. It has been known to follow blows and falls on the head which have produced no injury to the skull. It is rather more commonly observed in early manhood than at other periods of life. Secondary meningitis may follow injury or disease of the cranial bones or of the dura, and of the brain. A frequent cause is extension of disease of the ear to the membranes and substance of the brain. The reader is referred to the article on MEDICAL OTOLOGY for information concerning the symptoms of that formidable complication. Certain diseases are known to be occasionally complicated with meningitis—acute articular rheumatism; erysipelas of the scalp and of the face; Bright's disease, especially the chronic interstitial form; peritonitis; ulcerative endocarditis; pyæmia; the eruptive fevers; the puerperal state; and syphilis. Meningitis following or complicating acute rheumatism is generally supposed to be not uncommon, but the number of cases in which the existence of inflammation of the meninges has been proved by autopsy is small. Fuller,15 along with three cases in which dissection showed suppurative inflammation of the pia, cites several others in which no cerebral disease was found after death, although the symptoms gave every indication of it. True meningitis is rare in chronic Bright's disease, the symptoms resembling it being caused, in the majority of cases, by uræmia. Meningitis complicating pneumonia is also rare, although cerebral symptoms are common enough in that disease, especially in young children with inflammation of the upper lobes. C. Neuwerk16 reports seventeen cases of purulent meningitis complicating acute pneumonia. It was more frequent in men, especially in alcoholic subjects, than in women. The meningitis was generally total. The lungs were in a state of gray or yellow hepatization.
15 H. W. Fuller, M.D., On Rheumatism, Rheumatic Gout, and Sciatica, 3d ed., Philada., 1864, p. 271. See also E. Leudet, Clinique médicale de l'Hôtel Dieu de Rouen, Paris, 1874, p. 133.
16 Deutsches Archiv für klin. Med., xxix., 1881, p. 1; and Schmidt's Jahrbücher, Band cxcviii., 1883, Nov. 5.
SYMPTOMS.—The symptoms of acute leptomeningitis vary much in the course of the disease. This is readily explained by the complex character of the functions of the parts involved in the inflammation. It may be assumed that the cortical layer of the brain is implicated in every case unless of the most transient and limited kind; the substance of the brain, cerebellum, and medulla are subjected to pressure from the afflux of blood, from the effused lymph and pus, and from the accumulation of serum in the ventricles; the cranial nerves are exposed to pressure from the deposit of lymph, which may give rise to irritation or to suspension of function or both; parts at a distance from the seat of lesion may be functionally disordered by reflex action through communicating filaments. Finally, the general system suffers from the effects of the high fever upon the blood and the nutrition.
It is customary to speak of a stage of excitement followed by one of depression as characteristic of the course of the disease; but although active symptoms generally prevail in the early period, to be succeeded later by coma and paralysis, this disposition is by no means uniform. Sometimes sopor and paralysis constitute almost the only symptoms throughout the disease—this is especially noticed in infants—or active delirium and convulsions may persist until the fatal termination. More frequently the two conditions alternate several times with each other. A prodromic period of short duration, a few hours or a day or two, is sometimes observed in primitive meningitis, the patients complaining of headache, vertigo, vomiting, restlessness, or lassitude. Infants are irritable or drowsy, with heat of the head, quick pulse, and occasional vomiting. In secondary meningitis this period is usually masked by the symptoms of the primitive disease. In the majority of cases the beginning of acute meningitis is abrupt. Rigor is sometimes the first symptom observed, and in children is usually represented by a convulsion. More commonly, however, the disease is ushered in by severe headache, which is often referred to the forehead. The head is hot, the face is flushed, the eyes are brilliant, the pupils are contracted, the pulse is quick and hard, the temperature high (104° F. or upward). The patient is wakeful, restless, and irritable, sensitive to light and to sound. The skin is hyperæsthetic, especially that of the legs. There may be wandering or even active delirium. Vomiting is not unfrequent. There is thirst, but no desire for food. The urine is scanty and high-colored, the bowels constipated. These symptoms gradually increase in intensity, especially the pain in the head and the delirium, and in many cases they are followed by convulsions, at first in the form of twitchings of the facial muscles or of the limbs, grinding the teeth, etc., which give place to tonic contractions of the limbs or of the trunk, often confined at first to one or both members of the same side, but afterward becoming general; the flexors of the forearms and of the legs are most usually affected. The upper dorsal muscles may become contracted, so that the head is drawn backward, and more rarely trismus occurs.
A diminution in the rapidity of the pulse, which may fall to the normal rate, or even below that, notwithstanding the persistence of the high temperature, indicates the beginning of the stage of depression. This change is sometimes sudden, though more often gradual in its approach. The activity of the delirium subsides, giving place to a somnolence which may seem to the inexperienced observer a favorable indication, but which soon deepens into coma. The face becomes pale, the features are sunken. Only an occasional grimace or a movement of the hand to the head shows that the patient is to some extent conscious of suffering. This condition may alternate with the previous one from time to time, the comatose state being interrupted by noisy delirium and tonic or clonic convulsions, or even a partial return of consciousness, giving rise to fallacious hopes on the part of the friends, and sometimes deceiving the physician himself into a belief that a favorable issue is at hand. Before long, however, the symptoms of brain-compression become permanent. The rigidity of the limbs gives place to complete resolution. The patient lies absolutely unconscious, with dilated pupils. The pulse becomes again rapid in consequence of compression of the medulla, and thread-like and irregular; for the same reason the respirations increase to 40, 50, or 60 in the minute. The sphincters are relaxed, and the patient dies without any recurrence of the active symptoms. In rare cases recovery takes place, although almost never after the symptoms of compression have continued without interruption for any considerable length of time. Moreover, it is seldom that recovery takes place in the adult without leaving some traces of permanent damage, such as general debility, paralysis of one or more limbs, deafness, mental weakness, epilepsy, etc. Many cases of general paralysis of the insane and other forms of so-called mental disease are the result of meningitis.
DURATION.—In the adult usually the disease lasts about a week or ten days; exceptionally, it may last two or three weeks.
COURSE.—In young children the course of meningitis differs somewhat from that which is observed in adults, though the symptoms are essentially the same. It is more sudden in its onset and shorter in its duration. The prodromal stage may be brief or hardly noticeable; but in older children restlessness, sensitiveness to light and sound, wakefulness, slight twitchings of the features or of the limbs, a half-open condition of the eyelids during sleep, occasional vomiting, etc., are more commonly noticed. Convulsions are more common than in the adult, and sometimes constitute the chief symptom. They may be confined to a single extremity, but in general they shift from one limb to another. The muscles of the eyeball are usually implicated, causing strabismus. Retraction of the head is rarely absent, especially in young infants. These convulsions are almost always tonic, but occasionally they alternate with clonic ones. Distension and increased pulsation of the anterior fontanel is always observed in infants a few months old affected with this disease. When meningitis is secondary to some other disease, the first symptom noticed in children is apt to be vomiting, with delirium. According to Steffen, pneumonia is the disease most frequently complicated with meningitis in children. As in tubercular meningitis, the most prominent symptom may be mere sopor, sometimes with intervals of intelligence. Simple meningitis in children is generally a rapid disease, proving fatal in most cases within a week, and sometimes even in a few hours. Exceptionally, it may last much longer. A case occurring in a girl six years old, the duration of which was fifty-five days, is reported by J. Bokai, Jr.;17 the diagnosis was substantiated by autopsy. Another case, which recovered after seven weeks, is mentioned by Henoch.18
17 Jahrb. f. Kinderkrankheiten, N. F., xviii. 1, p. 105; and Schmidt's Jahrb., 1882, No. 6, p. 269.
18 Eduard Henoch, Vorlesungen über Kinderkrankheiten, Berlin, 1881, p. 277.
PATHOLOGICAL ANATOMY.—The lesions, which are rarely general, may occupy a greater or less extent of the membrane. They are usually disposed symmetrically with regard to the two hemispheres, or occupy corresponding regions of the base. The vessels are in the beginning of the disease distended, the finest ramifications being injected, giving a red color to the membrane, which varies in different places from crimson to light pink. The perivascular spaces of the larger vessels are filled with a grayish or yellowish fluid composed of extravasated liquor sanguinis and white blood-corpuscles. The meshes between the two layers of the pia are soon infiltrated with pus, and the thickened membrane can be stripped off from the surface of the brain, which is, however, adherent to it in places and is torn in the process. Sometimes a thin layer of pus, which can be scraped off with the knife, is found upon the surface of the pia. The extent of the lesion varies much in different cases. It may be confined to a limited region of the hemispheres, or it may spread to the fissure of Sylvius, where two surfaces become adherent. Sometimes the concrete pus and fibrin are deposited in thick masses upon the base of the brain, often completely surrounding the cranial nerves, and even the medulla. The inflammation may extend to the lateral ventricles, which become filled with a turbid fluid containing pus-cells, and sometimes wholly purulent. The choroid plexuses are often covered with flecks of pus. When the distension of the ventricles is very great, the gyri of the brain are more or less flattened by compression against the cranium, and the outer layer of the cerebral substance is bloodless and œdematous. The cerebral sinuses are distended with blood, and frequently contain thrombi due to an early stage of the inflammatory process, besides recent coagula.
DIAGNOSIS.—The diagnosis of acute meningitis is often difficult, and sometimes impossible, especially in the early stages, when the line between congestion and inflammation cannot be drawn, and in complicated cases. The typical symptoms are sudden and acute pain in the head, with sensitiveness to light and sound, contracted pupils, rapid pulse, and vomiting, followed by delirium, convulsions, and coma. If these symptoms were observed in an individual previously in good health, they would be strongly suggestive of the disease, and yet many of them are often present in the beginning of pneumonia, erysipelas, typhoid, typhus, and other eruptive fevers, uræmia, and poisoning from narcotic substances. Hence it is important to eliminate these sources of error before coming to a conclusion, and a neglect of this precaution is a not infrequent source of error in the diagnosis. A careful examination of the urine will generally enable us to exclude uræmia. The presence or absence of the eruptive fevers can usually be determined by the attendant circumstances, and yet cases of scarlatina, typhoid fever, variola, etc., beginning with active cerebral symptoms, are sometimes hastily pronounced to be meningitis by inexperienced observers. In poisoning by narcotics the history will often aid us in the diagnosis; moreover, except in the case of opium, the pupils are dilated instead of being contracted. In traumatic cases, with fracture of the cranial bones, it is always difficult, and often impossible, to distinguish between the symptoms of meningitis and those due to other lesions. In concussion without fracture we must be guided in our diagnosis by the same rules as in idiopathic cases. The distinction between extreme congestion of the pia mater and meningitis must be based chiefly upon the duration of the symptoms. The former is usually brief in its course; the latter lasts one or two weeks, and in cases which recover is often followed by after-effects which are more or less permanent in their duration, such as paralysis or rigidity of the limbs, mental defects, etc. Rapid recovery from the acute symptoms would be strongly suspicious of congestion, and doubtless in many such cases the treatment has been credited with a success to which it was not entitled. The diagnosis from tubercular meningitis will be reserved for the article on that disease.
PROGNOSIS.—Acute meningitis is fatal in the majority of cases, though recovery is possible. A gradual diminution of the severity of the symptoms, especially in respect to temperature, pulse, pain in the head, and other cerebral phenomena, would afford encouragement, but we must not trust too much to the brief appearances of amendment so often observed.
TREATMENT.—The indications for treatment are threefold: 1st, to prevent or arrest the inflammation; 2d, to modify its violence and shorten its duration when arrest is no longer possible; and 3d, to place the patient in the best condition to withstand the violence of the disease and to recover from its effects. It is only by prompt action that we can hope to attain the first object, that of preventing the passage of hyperæmia into inflammation. The patient should be placed in a cool and well-ventilated apartment of good size, from which a bright light is excluded. His head, moderately raised, should be kept cool by means of pounded ice enclosed in a rubber bag or a bladder. One or more leeches, according to his age, should be applied behind the ears, or blood may be drawn from the temples or back of the neck by means of cupping. The bleeding should be encouraged by poultices if necessary, but with young children the abstraction of blood should be done with caution. An active purge should be given, such as ten grains each of calomel and jalap, followed by castor oil or infusion of senna; for children, from three to six grains, according to age, followed by oil, would be sufficient. The medicine should be repeated in a few hours if there be no effect. Counter-irritation by means of blisters is recommended by most authorities as a valuable aid in the first stage of the disease. Unless the application be very extensive, it is not likely to be of any avail, and extensive blistering would hardly fail to greatly reduce the strength of the patient, and also is likely to irritate the kidneys. There are no medicines which can be relied upon to arrest the inflammatory process. Nevertheless, the tincture of aconite-root, in the dose of from one to three drops, according to the age of the patient, every two hours, might be given early, with the view of fulfilling the second indication by its sedative property. The bromide of potassium or of sodium, combined with small doses of chloral hydrate or of sulphate of morphia, will also calm the excitement and pain, and diminish convulsions. The success which sometimes follows the employment of ergot in the epidemic cerebro-spinal meningitis warrants its trial. Bartholow recommends the wet sheet two or three times a day if the temperature is high. Steffen advises four grains of sulphate of quinine with one grain of salicylate of soda, from two to four times daily, for young children, and in double these doses for older ones. The alimentation of the patient should be carefully attended to during this stage. Nourishing liquid food, such as milk, gruel, broth, eggs, with stimulants if indicated, should be given at proper intervals, care being taken not to overload the stomach, as is frequently done. When the patient can no longer swallow the food must be given by the rectum. During the stage of compression it is useless, in the present state of our knowledge, to expect any benefit from the further administration of drugs, and the treatment then consists mainly in giving small quantities of food at regular intervals, and in such external applications as the bodily temperature may require. The bladder must be relieved by the catheter when necessary. Simple enemata are generally sufficient to prevent constipation.
Chronic Cerebral Meningitis.
Chronic inflammation of the pia mater rarely follows the acute form, but is generally secondary to other conditions, such as inflammation and tumors of the dura, tumors and abscess of the brain, disease of the vessels of the brain, suppurative otitis, and to constitutional diseases, especially alcoholism, syphilis, and pulmonary tuberculosis. It is one of the most common lesions found after death from general paralysis of the insane. As a distinct affection, unconnected with constitutional disease, it is extremely rare, though less so, according to Flint,19 than the acute form. He cites a case in which the symptoms were intermittent. The patient, fifteen years old, died after a month's illness. The autopsy showed cerebral hyperæmia, lymph at the base of the brain, and distension of the ventricles with transparent fluid. There were no tubercles. In most cases in which the results of chronic meningitis are found after death the cortical substance of the brain is involved in the disease; hence the difficulty in defining its symptoms, which are usually extremely vague, and not always distinctive of cerebral disease. The principal are pain in the head, vertigo, vomiting, impairment of the memory, mental apathy, drowsiness, and muscular weakness. The anatomical changes are thickening and opacity of the membrane by the deposit of lymph upon its surface and into the connective tissue, adhesions to the dura and to the cortical substances of the brain, together with hyperæmia of the latter. These appearances are usually distributed in irregular patches of greater or less extent.
19 Austin Flint, M.D., Principles and Practice of Medicine, 5th ed., Philada., 1881, p. 701.
The DIAGNOSIS of chronic meningitis is often obscure or impossible. Long-continued pain in the head, accompanied by vertigo, impairment of memory, drowsiness, mental apathy, etc., without paralysis, would be suggestive of it, especially if there were occasional intermissions of the symptoms. The probability would be greatly increased if the patient had a syphilitic or alcoholic history. The diagnosis should exclude tumor of the brain, chronic pachymeningitis, and chronic hydrocephalus, but as these diseases are often complicated with chronic meningitis, the distinction might be very difficult. As already stated, chronic meningitis is almost a constant lesion in general paralysis, as well as in other forms of chronic insanity, but there are no special symptoms by which its presence can be ascertained during life.
TREATMENT.—Our aim should be to relieve pain, diminish congestion, and favor absorption. Counter-irritation to the head and nucha by means of small blisters or croton oil should be employed with moderation. Bromide of potassium, or, if necessary, small doses of morphia, may be given if the pain be severe. Should there be symptoms of cerebral congestion, such as acute delirium, flushing, and heat of head, an ice-bag should be applied to the head and leeches behind the ears, or blood may be drawn from the temples or nucha by cupping. As an absorbent the iodide of potassium is much recommended, but it is not likely to be effectual, except in syphilitic cases. The bowels should be kept free, but without active purging. The general health of the patient should be promoted by suitable diet and regimen, by relief from excitement and fatigue, or by change of scene and of climate. For the treatment of chronic meningitis complicating syphilis, alcoholism, and tuberculosis, the reader is referred to the articles treating of those diseases.