Carpal tunnel syndrome - electrodiagnostic aspects of fifty seven symptomatic hands.

Electrodiagnostic data of fifty seven symptomatic extremities with carpal tunnel syndrome (CTS) are described. Practice recommendations made by American Academy of Neurology, American Association of Electrodiagnostic Medicine and American Academy of Physical Medicine and Rehabilitation regarding electrodiagnostic studies were considered while confirming CTS diagnosis by electrodiagnostic studies. Median sensory nerve conduction studies were the commonest abnormalities noted. The median orthodromic sensory latencies were prolonged in 86% and sensory nerve action potential amplitude abnormalities were seen in 82%. Prolongation of the conduction in the short segment across the wrist in the median nerve was seen in 96.5% and the difference in the conduction between median and ulnar nerve across the wrist was significant in all the 57 extremities. The median motor latencies were prolonged in 67% of hands. Higher incidence of electrodiagnostic abnormalities observed in this study might be due to inclusion of patients with severe disease.