Pronator syndrome: clinical and electrophysiological features in seven cases.

The clinical and electrophysiological picture of seven patients with the pronator syndrome is contrasted with other causes of median nerve neuropathy. In general, these patients have tenderness over the pronator teres and weakness of flexor pollicis longus as well as abductor pollicis brevis. Conduction velocity of the median nerve in the proximal forearm is usually slow but the distal latency and sensory nerve action potential at the wrist are normal. Injection of corticosteroids into the pronator teres has produced relief of symptoms in a majority of patients.