Predicting the Outcome of Unilateral Vocal Fold Paralysis: A Multivariate Discriminating Model Including Grade of Dysphonia, Jitter, Shimmer, and Voice Handicap Index-10

Abstract

Objectives: The aim of this study was to investigate if any clinical and phoniatric characteristics or quality-of-life measures could predict the outcome of unilateral vocal fold paralysis (UVFP) initially managed with speech therapy. Methods: Forty-six patients with UVFP were evaluated using laryngostroboscopy, the GIRBAS (grade, instability, roughness, breathiness, asthenia, and strain) scale, acoustic analysis, and the Voice Handicap Index-10 (VHI-10) questionnaire. Treatment was speech therapy according to a 3-phase protocol. The main outcome measure was incomplete vocal fold mobility 12 months after symptom onset. Univariate and multivariate modeling ( k-nearest neighbors model) were applied. Results: Fifteen patients had incomplete motion recovery 12 months after the onset of UVFP. On univariate analysis, time to diagnosis (0.01), global grade of dysphonia (0.018), jitter (0.01), shimmer (0.012), and VHI-10 score (0.006) were associated with the outcome of vocal fold paralysis. Using a k-nearest neighbors multivariate discriminating model, the best discrimination of UVFP outcome was achieved with 4 parameters: global grade of dysphonia 2 or 3, jitter > 2.46%, shimmer > 6.97%, and VHI-10 score > 13. The model’s misclassification rate for incomplete motion recovery was only 6%. The model showed sensitivity of 93% and specificity of 74%. Conclusions: Delayed diagnosis and speech therapy was associated with negative outcomes. Higher grade of dysphonia, jitter, shimmer, and VHI-10 score on initial phoniatric assessment may help clinicians in predicting the outcomes of UVFP patients.