Botulinum toxin treatment of false vocal folds in adductor spasmodic dysphonia: Functional outcomes

Supraglottic injection of botulinum toxin (Botox) has been described as an effective treatment for adductor spasmodic dysphonia (ADSD). Anecdotal evidence suggests that the patients have little to no breathiness after injection, but no formal longitudinal studies have been carried out to date. The purpose of this study was to examine the voice outcomes in patients with ADSD after supraglottic Botox injection.

Retrospective case series.

Patients with ADSD who were treated with supraglottic Botox injections completed a qualitative self-evaluation of voice function after injection using the percentage of normal function (PNF) scale, a validated, quantitative scale from 0% (no function) to 100% (normal function). Posttreatment voice improvement after injection was determined using a Voice Handicap Index-10 (VHI-10) questionnaire.

A total of 198 supraglottic injections were performed between July 2011 and October 2014. Twenty-five questionnaires were completed. Mean postinjection PNF was 95.0% ± 8.4% and was significantly increased from the preinjection mean PNF (62.5%) ± 22.6% (P < 0.001). The mean best VHI-10 for all injections was 7.23. In 19 of 25 patients (76%), there was no reduction in PNF in the early postinjection period. In the remaining six patients (24%), the decline in mean vocal function was 9.2%.

Supraglottic Botox injection is an effective treatment for ADSD. Postinjection voice is significantly improved, and the majority of patients do not experience breathy voice/decline in vocal function after injection.