Prospective Quantitative Laryngeal Electromyography Changes in Patients With Iatrogenic Unilateral Vocal Fold Paralysis

ObjectiveTo track quantitative laryngeal electromyography (LEMG) and voice outcome survey (VOS) changes over 12 months postiatrogenic unilateral vocal fold paralysis (UVFP). To explore the factors influencing these changes.Study DesignHistorical cohort study.SettingTertiary medical center.MethodsPatients who developed UVFP after surgery underwent a series of assessments, including quantitative LEMG, videolaryngostroboscopy, voice acoustic analysis, and completion of the VOS at diagnosis and at the 12-month follow-up. The subsequent data from these assessments were then compared for analysis. Bivariate analysis examined predictors of changes in VOS and LEMG data respectively, with significant factors further included in a multivariate regression model.ResultsThe study enrolled 99 patients. LEMG data were prospectively collected within 3.9 months (+/- SD: 0.2) postsurgery, followed by an average 13.2-month (+/- SD: 0.2) follow-up. A worse initial turn ratio of thyroarytenoid-lateral cricoarytenoid muscle correlated with more significant subsequent improvement in LEMG findings, reflecting a similar trend observed in the change of VOS scores.ConclusionThis study contributes valuable insights into the temporal change of quantitative LEMG and VOS in patients with iatrogenic UVFP. It suggests that poor initial LEMG and VOS results do not necessarily determine a worse prognosis in terms of electrical activity.