Locomotor Ataxia, or TABES DORSALIS, is a remarkable disease of the nervous system, the most characteristic symptom of which is a want of power of co-ordinating the muscles. The lower limbs are almost always first and most severely affected, and the patient walks with a peculiar gait; he lifts the feet high and brings them down with a stamp; he has difficulty in balancing himself; and though he may be able to walk pretty well in a straight line on level ground, any more complicated movement (turning round, surmounting or avoiding obstacles, &c.) much increases his unsteadiness. When deprived of the aid of sight (in the dark, or on closing the eyes) these difficulties are much aggravated. In the great majority of cases sensation is early affected; and he may complain that he always feels as if he were walking upon a thick carpet. The power of the muscles is in many cases quite unimpaired.
Besides the symptoms of incoordination, and often long preceding them, are others, some of which are so characteristic that they may lead to the recognition of the disease. Severe shooting pains, especially in the lower limbs (called lightning pains), are frequent. Similar pains in the region of the stomach, associated with vomiting, faintness, &c. (gastric crises); paralysis, often transient, of one of the eye-muscles; extreme contraction of the pupil; atrophy of the optic nerve; a peculiar form of inflammation of one or more joints, are all met with in a certain proportion of cases.
The progress of the disease is always slow and uncertain; it may generally be measured by years, often by decades; but, although in some cases the condition of the patient may remain stationary for years, it generally becomes gradually worse. Death usually results from some intercurrent disease. Locomotor ataxia generally begins between the ages of thirty and fifty, and is much more common in the male sex. It seems sometimes traceable to severe acute illness, to chill, over-fatigue, injury, &c., and many of those who suffer from it have previously had syphilis; but in a large number of cases no cause is discoverable.
After death a fibrous degeneration (sclerosis) of the whole or part of the posterior columns of the spinal cord is found. The extremely uncertain course of the disease renders it very difficult to be certain of the effect of treatment, though many different methods have been advocated, and asserted to produce amendment if not cure. The most hopeful cures are those which follow syphilis; for in them a prolonged antisyphilitic treatment not unfrequently seems to lead to great improvement or even disappearance of the symptoms.