Sensory conduction studies of the branches of the superficial peroneal nerve

A method for obtaining antidromic conduction velocities in the sensory branches of the superficial peroneal nerve at the level of the ankle was evaluated. An essential prerequisite for the study of this nerve is knowledge of its exact topography. The method included the placing of surface recording electrodes directly over the branches of the nerve and stimulating the superficial peroneal nerve at the anterolateral aspect of the leg. The right lower extremity of 80 normal subjects was evaluated. The mean values obtained from the medial dorsal cutaneous branch at a distance of 14cm were 2.8 +/- 0.3 msec, 51.2 +/- 5.7 msec, 18.3 microV for the latency to onset of negative deflection, conduction velocity and amplitude, respectively. Similar values were obtained from studies of the intermediate dorsal cutaneous branch. In ease of performance and in reliability, sensory conduction studies in the branches of the superficial peroneal nerve were found to be equal to those of the sural nerve and superior to those of the saphenous nerve. The described technique should be helpful in the electrodiagnostic evaluation of peripheral neuropathy as well as of local neuropathic conditions and entrapment syndromes involving the peroneal nerve or its sensory branches.