Technical, Physiological and Anatomic Considerations in Nerve Conduction Studies

Abstract

Nerve conduction studies and their interpretation are subject to a variety of factors. First, technical factors including submaximal stimulation, environmental electrical noise, inaccurate placement of the recording electrodes, and stimulus artifact can substantially interfere with accurate recording of nerve and muscle responses. Second, physiological factors, such as the effects of body height and age, can cause profound variation in all nerve conduction parameters, and studies require interpretation keeping these individual variations in mind. Another physiological factor is temperature, in which cooling can produce a variety of changes, including slowing of conduction velocity and increase of response amplitude. Anatomic factors are also important, the most common being the Martin-Gruber anastomosis, usually presenting with a reduction in response amplitude with proximal stimulation of the ulnar nerve, and the second most common being the presence of an accessory peroneal nerve. Paying constant attention to all of these details is a critical element to the accurate performance and interpretation of nerve conduction studies.