Electrodiagnostic evaluation of peripheral nerve injuries

Electrodiagnostic studies of peripheral nerve function remain a valuable adjunct to a thorough clinical examination. The electromyogram and sensory evoked response of the peripheral nerve aid in determining the diagnosis and severity of some neuropathies. The use of signal averaging microprocessors to enhance small evoked responses is adding another dimension in electrodiagnostic studies. This tool provides evaluation of the peripheral nervous system in conjunction with the central nervous system. The intraoperative use of electrodiagnostic studies is readily performed using widely available equipment, but does require a thorough understanding of the equipment used. The equipment, principles, and helpful hints in applying electrodiagnostic techniques to the evaluation of peripheral nerves is reviewed.