Effects of botulinum toxin on pathophysiology in spasmodic dysphonia

Document Type

Journal Article

Publication Date

1-1-2000

Journal

Annals of Otology, Rhinology and Laryngology

Volume

109

Issue

2

DOI

10.1177/000348940010900215

Keywords

Botox; Botulinum toxin; Electromyography; Laryngology; Larynx; Spasmodic dysphonia; Voice

Abstract

To determine the mechanism of symptom relief with treatment by botulinum toxin injection in persons with adductor spasmodic dysphonia (ADSD), we evaluated the effects of unilateral thyroarytenoid muscle injections on both injected and noninjected muscles in 10 subjects with ADSD, using electromyography on both sides of the larynx before and after treatment. The subjects' speech symptoms were reduced (p = .005) 2 weeks following injection, when the electromyographic study occurred. Muscle activation levels and the numbers of spasmodic muscle bursts decreased significantly (p ≤ .03) postinjection in both the injected and noninjected muscles. The reductions in laryngeal muscle bursts correlated with symptom reduction (r ≥ .7) in all muscles. Reductions in laryngeal muscle bursts did not relate to either absolute or normalized levels of muscle activity before or after botulinum toxin injection. The results suggest that changes in the central pathophysiology are responsible for changes in speech symptoms following treatment.

This document is currently not available here.

Share

COinS