Laryngeal EMG for Unilateral Vocal Fold Paralysis

Abstract

Objective: 1) Examine the accuracy, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of using laryngeal electromyography (LEMG) to predict the prognosis of unilateral vocal fold paralysis (UVFP). 2) Provide better evidence support for using LEMG to predict the prognosis of UVFP via a prospective long-term study. Method: Sixty-six patients with UVFP were prospectively collected from 2007 to 2011. LEMG findings were dichotomized to negative (good prognosis) or positive (poor prognosis). The motions of paralyzed vocal folds were followed by videolaryngoscopy at least 3 months after LEMG. and the association with LEMG findings were analyzed. Results: The mean duration of LEMG after symptoms onset and follow up after LEMG were 3.4 months and 12 months, respectively. Fifty-seven patients had positive findings (less than 80% of normal motor unit recruitment or presence of fibrillations) in LEMG and 55 patients remained UVFP in the follow-up. Nine patients had negative findings (80%-100% motor unit recruitment) in LEMG and 3 patients recovered vocal fold motion. LEMG findings are significantly associated with the outcome of UVFP ( P = .016; Fisher’s exact test). The accuracy, sensitivity, specificity, PPV, and NPV of LEMG were 87.9%, 90.2%, 60%, 96.5%, and 33.3%, respectively. Conclusion: This study confirms that LEMG can reliably offer prognostic information for UVFP. Especially for patients with positive finding of LEMG, the chance of recovery of vocal fold motion will be very low.