Clinical Value of Motor Nerve Conduction Velocity Determination

It is important to distinguish between neuropathic diseases that primarily affect the nerve axon and those affecting the anterior horn cell; for example, polyneuritis and poliomyelitis. Measuring the conduction velocity of the motor fiber, which is usually reduced in conditions affecting the axon is a practical electrodiognostic procedure. The median and ulnar nerves in the forearm and the deep peroneal and posterior tibial nerves in the leg are suitable for such diagnostic study. Of 300 patients examined by this technique 41 had reduced velocity in one or more nerves. The diseases involved were virus encephalomyelitis, regenerating peripheral nerve injuries, progressive neuropathic muscular atrophy, chronic polyneuritis, and neuropathies due to diabetes, alcohol, or local lesions. The histories of a 6-month-old child with infectious neuronitis and a man with acute polyneuritis illustrate the use of this diagnostic procedure.