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.