Intraoperative pediatric laryngeal electromyography: experience and caveats with monopolar electrodes

We report our experience with intraoperative laryngeal electromyography (L-EMG) using direct laryngoscopy and placement of monopolar electrodes under general anesthesia in the evaluation and management of laryngeal dysfunction in pediatric patients. In this series of case studies, we present clinical data on 30 pediatric patients with known or suspected anatomic or neurologic laryngotracheal disorders evaluated with placement of shielded monopolar electrodes into the thyroarytenoid muscles during direct laryngoscopy under general anesthesia. Diagnoses included congenital vocal fold paralysis (VFP), laryngotracheal stenosis, cerebral palsy, laryngeal tumors, traumatic vocal fold dysfunction, and postsurgical VFP. The impact of L-EMG on patient management was assessed. We found that L-EMG objectively supported clinical findings, but provided new objective data relevant toward management recommendations in only a few selected pediatric patients with new-onset vocal fold paralysis or paresis or infiltrative laryngeal tumors, and in selected postsurgical cases involving decannulation decisions. The prognostic utility of L-EMG in newborns with congenital VFP has not been established. A normal L-EMG recording indicates an intact neuromuscular axis, but does not guarantee vocal fold mobility or guarantee muscle function in a partially denervated or deconditioned muscle. The potential for false-negative recordings is the major limitation of this technique.