Motor nerve conduction in the carpal tunnel syndrome

Abstract

Observations on motor nerve conduction were made in 95 patients with a suspected diagnosis of the carpal tunnel syndrome. With stimulation of the median nerve trunk just above the wrist, the latency of the muscle action potential in the abductor pollicis brevis was abnormally prolonged in approximately two-thirds. Conduction velocity was also moderately reduced over the forearm and upper arm in patients with a conduction delay distal to the wrist. The significance of the electrical findings is discussed.