Technique for studying conduction in the lateral cutaneous nerve of calf.

We describe a novel technique for assessing conduction in the lateral cutaneous nerve of the calf (LCNC), a branch of the common peroneal nerve, based on a study of 32 healthy subjects. Both antidromic and orthodromic techniques were used in each of the 64 limbs to obtain a sensory nerve action potential (SNAP) of the LCNC over a distance of 12 cm. In 60 limbs (93.7%) a SNAP was obtainable with either the antidromic or orthodromic technique. In 21 limbs (32. 8%), the SNAP was obtained both antidromically and orthodromically. In 33 limbs (51.6%), the SNAP was obtained only antidromically, and in 6 (9.4%), only orthodromically. In four limbs, the response was unobtainable. Mean antidromic onset latency was 2.1 ms +/- SD 0.3, peak latency was 2.6 ms +/- SD 0.4, amplitude (without averaging) was 4.3 microV +/- SD 2.5, and conduction velocity was 60 m/s +/- SD 10. Mean orthodromic onset latency was 2.3 ms +/- SD 0.3, peak latency was 2.7 ms +/- SD 0.3, amplitude was 5.0 microV +/- SD 2.2, and conduction velocity was 52 m/s +/- SD 5. Utilization of this technique allows for more detailed localization of common peroneal nerve injury based on whether it is proximal or distal to the origin of the LCNC. Copyright 2000 John Wiley & Sons, Inc.