Electromyographic Findings in Recurrent Laryngeal Nerve Reinnervation

Abstract

Abductor, adductor, and combined reinnervation procedures have been explored with variable success rates. We describe the experience of a tertiary care center with adductor reinnervation procedures, including preoperative and postoperative videostroboscopy and electromyography (EMG) findings. A retrospective chart review was performed from 1997 to 2001 that included 9 patients. Preoperative and postoperative voice comparison was performed by 3 blinded speech pathologists. Clinical comparisons of videostroboscopy findings for vocal fold bulk, tone, position, presence of gap, and movement are elucidated. The preoperative and postoperative EMG findings are described. In all patients, preoperative EMG revealed a dense, complete denervation of the affected recurrent laryngeal nerve. No movement was noted on videostroboscopy with persistent glottic gap. Reinnervation involved a nerve-muscle pedicle or a direct neurorrhaphy of the ansa cervicalis to the recurrent laryngeal nerve. Voice improvement was noted between 60 days and 3 months after reinnervation. Four postoperative EMG studies were performed. An early postoperative EMG study at 5 months revealed activation of the lateral cricoarytenoid muscle and thyroarytenoid muscle with head-lift. Videostroboscopy showed excellent near-midline static positioning of the vocal fold. Late EMG studies, performed 12 to 16 months after reinnervation, revealed “learning” of these muscles, with new activation on “eee” phonation. We conclude that recurrent laryngeal nerve reinnervation procedures belong in the armamentarium of the laryngologist for the treatment of vocal fold paralysis. The EMG findings reported in this study suggest that ongoing reinnervation allows for activation with phonation in matured neuronal anastomoses. Overall, this procedure results in excellent patient acceptance and near-normal vocal quality.