Author(s)
Daniel Novakovic, MPH, MBBS
, CPSP
Duy Duong Nguyen, MD, PhD
Antonia Chacon, BAppSc (SpPath), CPSP, Cate Madill, PhD
Affiliation(s)
University of Sydney
Abstract:
Background: Primary muscle tension dysphonia (MTD) is a common voice disorder characterized by inappropriate peri-laryngeal muscle tension during phonation without obvious neurogenic, psychogenic, or structural pathologies. Standard treatment includes modifying phonation behaviours with voice therapy. Some people remain symptomatic despite voice therapy (recalcitrant MTD). Objective: To examine the effectiveness of injection laryngoplasty (IL) as an adjunct to voice therapy in the treatment of recalcitrant MTD. Methods: Retrospective review of 40 patients with primary diagnosis of MTD recalcitrant to voice therapy who underwent subsequent IL (Mean age = 42.9 years; standard deviation, SD = 13.1; range = 23 - 71). Patients completed the Voice Handicap Index-10 (VHI-10) and read the vowel /a/, Rainbow Passage, and the third CAPE-V phrase. Voice data were acoustically analysed for maximal phonation time, vowel fundamental frequency, harmonics-to-noise ratio (HNR) and smoothed cepstral peak prominence. Data were compared between baseline and 6-12 weeks after IL. Results: VHI-10 data was available for 37 patients, mean (SD) VHI-10 decreased from 25.4 (5.9) at baseline to 16.3 (9.4) after IL (t = 5.899, p < 0.001, Cohen’s d = 0.7). Acoustic analyses were performed in 26 patients with pre- and post-surgical voice recordings available. Mean (SD) of HNR (dB) increased from 20.4 (5.0) at baseline to 22.5 (4.6) after IL (t = -3.022, p = 0.006, Cohen’s d = 0.517). No statistically significant differences were observed in other acoustic measures. Conclusion: IL can be an effective adjunct to voice therapy in the treatment of recalcitrant MTD. Further studies are indicated to examine the effects of IL in the management of MTD.