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.