Distal chronic spinal muscular atrophy involving the hands.

Six patients are described with a history of slowly progressive wasting of the muscle of the hands and forearms extending over periods of up to 20 years. The clinical, radiological, and electrophysiological findings were consistent with a diagnosis of chronic anterior horn cell degeneration. It is suggested that the patients are affected by a form of distal chronic spinal muscular atrophy affecting the hands.