A case of bulbospinal muscular atrophy with chief complaint of sensory disorder in the lower extremities.

A 56-year-old man was admitted to our department with a chief complaint of lower extremity dysesthesia. He described a dull numbness below the ankle and a dull pain in the nates for the past two years. Although the numbness extended to the thigh, he did not notice any muscular weakness or atrophy. Neurological examination revealed weakness and atrophy in the face, tongue and the proximal portions of all four extremities. Deep tendon reflexes were decreased. A moderate loss of vibratory sensation was noted below the knees. Electromyography showed neurogenic changes. Muscle biopsy revealed both myogenic and neurogenic changes. Sural nerve biopsy revealed a mild reduction of myelinated fibers, particularly the large-diameter fibers. Based on these findings, a diagnosis of bulbospinal muscular atrophy (BSMA) was made. In recent years, there have been some case reports of BSMA with sensory disturbances, or merely with subclinical manifestations of a sensory disturbance. This case is included in the same category as those reports, but it is interesting to note that the sensory disturbance in the lower extremities occurred as the chief complaint of the disease.