Nerve Conduction Studies on Patients of Sciatica

The sciatic nerve, which is the broadest nerve in the body, lies deep to the gluteus maximus, superiorly. Crossing posteriorly to the obturator internus, gemelli and the quadratus femoris musclesnerve divides into its tibial and common peroneal branches approximately halfway or more down the thigh. Electrophysiological investigation of human peripheral nerve has been extensively conducted over the past years. Motor conduction velocity determination has become a standard laboratory procedure, and its value in the diagnosis and localization of peripheral nerve lesions is well recognized. The method involves the application of an electrical stimulus on the skin overlying the nerve trunk with a surface electrode and the recording of muscle potential from a small muscle innervated by a terminal branch of the nerve.This procedure is, therefore, limited to a few superficially situated nerves. The latency and waveform of evoked muscle potential recorded from a big muscle vary with the nature and placement of recording electrodes, and their interpretation.