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

by Unknown

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.