Quantitative electromyography improves prediction in vocal fold paralysis

Objectives: Quantitative laryngeal electromyography (LEMG) using turns analysis can differentiate acute vocal fold paralysis from normal controls. The objective of this study is to determine if using both traditional qualitative LEMG measurements in addition to turns analysis improves prognostic accuracy in patients with acute vocal fold paralysis who demonstrate voluntary motor activity. Study Design: Retrospective review of LEMG data (qualitative and quantitative) and charts of patients with vocal fold paralysis on flexible laryngoscopy, recurrent laryngeal neuropathy, and varying degrees of motor unit recruitment. Methods: Laryngeal EMG using a standardized protocol involving qualitative (evaluation of recruitment, motor unit configuration, detection of fibrillations, synkinesis) and quantitative (turns analysis) measurements was performed. Prognosis was correlated with vocal fold motion recovery status (minimum of 6 months following onset) using positive and negative predictive values (PPV, NPV). Results: Twenty-three patients underwent LEMG for acute recurrent laryngeal neuropathy. All four patients with excellent LEMG prognosis recovered motion, whereas 17/19 patients with fair/poor LEMG prognosis were without motion at least 6 months following onset, resulting in a 100% PPV and 89.5% NPV. Conclusions: Integrating both qualitative and quantitative LEMG data improves prognostic accuracy in vocal fold paralysis patients who demonstrate voluntary motor unit activity.