Sensory studies of four fingers were performed on 72 patients with early (distal motor latency <4.2 ms) carpal tunnel syndrome (CTS) and on 43 control subjects. Results demonstrate that sensory studies of digit 4 yields the highest sensitivity (88%) for diagnosis of early CTS. The sensitivity of digit 1, digit 2, and digit 3 was 61%, 22%, and 50%, respectively.