| Abstract: |
Summary: Introduction: The hallmark characteristic of adductor spasmodic dysphonia (ADSD) is irregular and uncontrollable spasms within the intrinsic laryngeal muscles, resulting in erratic disruption of normal voicing. Methods: Using a random assignment and the inclusion of a behavioral sham to determine the effect of voice therapy after initial botulinum toxin type A (BTX-A) injections for ADSD, this study examined duration of injection benefit, perceived vocal quality of life from the Voice-Related Quality of Life (V-RQOL) scale, acoustic measures of vocal instability, and perceptual ratings of voice quality. Measures of these variables were collected before initial injection; 3, 7, and 12 weeks postinjection; and immediately before reinjection. Thirty-one individuals with ADSD participated in this study. One-third received no further intervention after BTX-A injection, one-third received a standard 5-week course of voice therapy after BTX-A injection, and one-third received a 5-week course of sham voice therapy after BTX-A injection. Results and Conclusions: Significant effects were observed on perceived quality of life and acoustic variables for all participants, over time. Participants who received voice therapy after BTX-A injection did not experience longer injection effect duration or significantly greater improvements in V-RQOL or acoustic variables than participants in BTX-A only or BTX-A plus sham therapy groups. Additionally, perceptual ratings of voice quality improved for all participants in response to BTX-A injection. For participants in this investigation, undertaking voice therapy did not appear to exert significant beneficial effects on the variables of interest. |
