Evaluation of Nerve Regeneration by Means of Nerve Evoked Potentials

A percutaneous technique of recording evoked nerve action potentials is described. It permits the evaluation of progress of regeneration after nerve injury in man, before the regenerative process has reached the appropriate distal muscles. A recording electrode is introduced percutaneously in the vicinity of the nerve trunk, proximal to the lesion. The nerve is then stimulated at several distal points with a cutaneous contact electrode. The potentials resulting from stimulation of the mixed nerve are recorded centripetally. If they are of low amplitude, an electronic average is used. The point along the nerve where a response can no longer be elicited is found. It can be assumed that regenerative activity has progressed to this point. Serial studies then allow evaluation of the progress of regeneration.