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.