While not, as a rule, an early symptom, motor incoordination, as manifested in ataxia, is one of the most significant and distinctive phenomena of tabes dorsalis. Usually manifesting itself after months or years, it may appear in the course of days or weeks. The disturbance in function is in marked contrast with the preservation of gross muscular power, the strength of any individual movement being retained, at any rate for a considerable length of time, before wasting from disuse sets in. Almost invariably the lower extremities are involved first, exceptionally the upper extremities. The muscles of the trunk also may suffer, and rarely those of the face, lips and tongue. The muscles of the vocal bands are said to be involved not infrequently.
The case to be reported is of interest because of a total absence of ataxia, although the disease of the spinal cord appears to be at least