The experiments which are reported here add new data through a study of the electrical response of regenerating canine laryngeal nerves. Evaluation was carried out by stimulating recurrent nerves surgically sutured after dissection. Action potentials elicited from laryngeal muscles innervated by regenerating recurrent nerves were studied at intervals up to 45 weeks following the primary suture. These data permit determining the correlation between electrophysiological findings and histological data obtained from some nerve specimens.
In summary, the items presented are: (1) During the early stage of regeneration process, fibrillation potentials of relatively low voltage were demonstrated.(2) In more advanced stages, electromyographic analysis showed mixed patterns of normal and abnormal interference patterns. However, no evoked potential was demonstrated.(3) After 24 weeks, electromyographic analysis showed a normal interference pattern. Evoked potentials revealed prolonged latency and a characteristic pattern.(4) After 45 weeks, evoked potentials revealed normal latency and relatively simple, diphasic or triphasic defletions. However, the amplitude of the evoked potentials was of low voltage.(5) Histologically, the regenerated nerve fibers were less in number and there was considerable development of fibrous tissue.(6) Even in cases of complete recovery on the electromyographic findings, vocal cord motion often differed from the normal behavior.
