LOCOMOTOR ATAXY. 307 



After having described and analyzed the most important symptoms, 

 L shall attempt to give a general description of tabes dorsualis, and pic- 

 ture the most frequent course of the disease as briefly as possible. 



In many patients, the characteristic disturbances of coordination, 

 and the decrease of cutaneous and muscular sensibility are preceded 

 for a long time, even for years, by attacks of severe tearing pain in 

 the lower half of the trunk, and in the lower extremities ; these are 

 generally considered as rheumatic. In other patients, on the contrary, 

 the first complaints are that the lower extremities become fatigued 

 very easily and very soon. Persons accustomed to walking notice that 

 they tire sooner and more easily than formerly. These symptoms, 

 which are not usually very suspicious, either to the patient or physi- 

 cian, may precede the decided symptoms of tabes for a long time. 

 But this difference in the initial symptoms is not so marked or decided 

 as it seems to be on superficial examination. The attacks of pain are 

 unmistakably neuralgic, and depend on morbid excitement of the pos- 

 terior roots, while the tendency to fatigue depends on their hyperses- 

 thesia that is, on their morbidly-increased excitability. Under physi- 

 ological circumstances, the feeling of fatigue depends on the amount 

 of work done by the muscles. The state of the muscles resulting from 

 overwork is perceived through the sensory muscular nerves. If the 

 excitability of the posterior roots be increased, slight exertion of the 

 muscles will produce the same effect, which would otherwise only be 

 induced by far greater exertion. Hence the tendency to fatigue in 

 tabes is perfectly analogous to the increased sensitiveness, at the com- 

 mencement of certain brain-diseases, to light, sound, and other irrita- 

 tions, which are not generally unpleasant. The tearing-pain and ten- 

 dency to fatigue in the lower extremities are not recognized to be 

 serious and threatening until they are accompanied by other disturb- 

 ances of sensibility, such as formication, a feeling of furriness, numb- 

 ness, and the sensation of a ligature around the abdomen. Gradually 

 the gait becomes uncertain and awkward ; at first this is so only in the 

 dark, so that the patients prefer remaining at home in the evening ; 

 afterward it is the same in day-time. The feet are lifted too high, and 

 thrown forward and outward, and then brought heavily down on the 

 floor. If the patient closes his eyes while standing erect, he begins tc 

 totter, and, unless supported, falls to the ground. And, even at this 

 time, he must usually be on his guard when the desire to urinate seizes 

 him, so that he may reach a convenient place in season. After a time, 

 walking becomes impossible, even with the aid of a stick or, crutches, 

 although, when the body is fixed, the patient can generally make un- 

 complicated movements of the extremities with nearly normal force. 

 The same uncertainty and awkwardness come on in the upper ex- 



