Treatment Efficacy of Voice Therapy Following Injection Laryngoplasty for Unilateral Vocal Fold Paralysis

Abstract

Injection laryngoplasty (IL) is performed to reduce the gap between vocal folds induced by unilateral vocal fold paralysis (UVFP). Voice quality after IL may be different due to other factors that influence voice quality. Voice therapy has been reported to improve voice quality after IL in patients with UVFP. This study evaluated the efficacy of voice therapy combined with IL. Patients with UVFP who underwent IL as primary therapy from March 2017 to June 2019 were evaluated. The enrolled patients were divided into two groups, those who did and did not receive voice therapy after IL. Voice quality was evaluated using perceptual, acoustic, and aerodynamic parameters, and voice handicap index-30 scores one month after IL and after completing each treatment. Of 261 patients who underwent IL during the study period, 40 were enrolled, including 21 who did and 19 who did not receive voice therapy. Voice parameters one month after IL did not differ between these two groups. Jitter, shimmer, noise-to-harmonic ratio, and mean flow rate decreased, while maximum phonation time increased after voice therapy (both P < 0.05). In the absence of voice therapy, improved voice parameters were maintained for six months after IL. Total voice handicap index-30 scores decreased, from 35.6 to 19.1 (P < 0.05), in patients who received voice therapy. Voice therapy following IL is beneficial to patients with UVFP. Combined treatment can help to maintain improved voice quality more than six months after IL.