Silent period abnormalities in carpal tunnel syndrome.

Cutaneous silent period (CSP) was measured on stimulating digits 2 and 5 in 19 patients with carpal tunnel syndrome (CTS) and compared with 20 healthy volunteers. In 2 patients with severe CTS, CSP was absent on digit 2 but present on digit 5. In mild/moderate CTS digit 2 CSP mean duration was 50.9+/-13.9 ms, significantly longer than control subjects (36.9+/-8.7 ms) (P = 0.005). CSP was found to be abnormal in CTS, being absent in severe and prolonged in mild/moderate cases.