Vibratory asymmetry in mobile vocal folds: Is it predictive of vocal fold paresis?

Objectives: The purpose of this study was to determine whether the videostroboscopic finding of vibratory asymmetry in mobile vocal folds is a reliable predictor of vocal fold paresis. In addition, the ability of experienced reviewers to predict the distribution (left/right/bilateral) of the paresis was investigated. Methods: This is a retrospective chart review of all patients who presented to our clinic during a 3-year period with symptoms suggestive of glottal insufficiency (vocal fatigue or reduced vocal projection) accompanied by the videostroboscopic findings of bilateral normal vocal fold mobility and vibratory asymmetry. Twenty-three of these patients underwent diagnostic laryngeal electromyography of the thyroarytenoid and cricothyroid muscles to determine the presence of vocal fold paresis. Results: Nineteen of the 23 patients (82.6%) were found to have electrophysiological evidence of vocal fold paresis, either unilaterally or bilaterally, when videostroboscopic asymmetry was present in mobile vocal folds. However, the three expert reviewers' ability to predict the distribution (left/right/bilateral) of the paresis was poor (26.3%, 36.8%, and 36.8%, respectively). Conclusions: The videostroboscopic finding of vibratory asymmetry in mobile vocal folds is a reliable predictor of vocal fold paresis in most cases. However, the ability of expert reviewers to determine the distribution (left/right/bilateral) of the paresis using videostroboscopic findings is poor. This study highlights the value of laryngeal electromyography in arriving at a correct diagnosis in this clinical situation.