We evaluated the sensibility of the hand preoperatively and at intervals
postoperatively in twenty-three hands of twenty patients with idiopathic
carpal-tunnel syndrome who underwent carpal tunnel release. Tests of
sensibility included the threshold tests (vibrometry, 256-cycles-per-second
vibration, and Semmes-Weinstein monofilaments) and one innervation-density
test (two-point discrimination). In addition the wrist-flexion test,
nerve-percussion test, and tourniquet test were performed preoperatively.
Only five of the twenty-three hands had abnormal two-point discrimination
and each of these also had markedly abnormal threshold-test values.
Nineteen of twenty-three hands preoperatively had decreased sensibility
detected by both Semmes-Weinstein monofilament testing and vibrometry. Six
weeks after carpal tunnel release, all of the hands demonstrated
improvement on threshold testing, and 65 per cent had normal values.