Sensory nerve conduction studies.

Sensory nerve conduction studies (NCS) are an indispensable component of the electrodiagnostic examination. They evolved from mixed NCS, and were initially described by Dawson in 1950. Gilliatt and Sears first reported their clinical value in 1958. Compared to motor NCS, sensory NCS are much less standardized. Variables regarding them include: (a) bipolar vs. monopolar recording; (b) antidromic vs. orthodromic technique; (c) needle vs. surface stimulating electrode(s); (d) needle vs. surface recording electrodes; (e) fixed vs. variable distances between cathode and active recording electrode; (f) measuring latencies to onset vs. to peak; and (g) measuring amplitudes baseline to peak vs. peak to peak. The value of sensory NCS with various peripheral nerve fiber lesions, including plexopathies, mononeuropathies, and polyneuropathies, is discussed.