Effects of Vocal Exercises for Spasmodic Dysphonia

Spasmodic dysphonia (SD) is a neurological disorder characterized by involuntary spasms of the vocal folds resulting in a strained and strangled voice quality. This disorder is quite disabling to patients who suffer from it, particularly affecting patients' quality of life. Botulinum toxin (Botox) has been found to be the most effective treatment for SD. The Botox is injected into the affected muscle resulting in temporary weakening of the muscle. The patients return for injections on average every 3 - 6 months. There is a suggestion in the literature that increased diffusion of the Botox injectate could improve the effects of the injection. Furthermore, there is literature supporting the use of exercise to increase the diffusion of the Botox. Previous research examined the use of voluntary muscle activity vs. rest immediately following Botox injection for writer's cramp. It was found that the active condition resulted in greater reduction of muscle strength in the injected muscle. Another small study of 9 patients implemented intense exercise comprised of loud reading for one hour and a rest condition of total voice rest for 24 hours. They found that the exercise condition resulted in improved scores on the voice related-quality of life (V-RQOL) measure and concluded that improvement in results of Botox injections may be achieved more consistently with the implementation of exercise following the injection. The exercise used in this study was intense and may be contrary to the overall benefit as the subjects may experience phonotrauma. Timing of the exercise post-injection may also be a factor. Previous literature review revealed combined modality treatment of Botox injection only, Botox with therapy and Botox with sham treatment. They found no significant differences in acoustic stability, V-RQOL, or duration of injection benefit. However, the exercise was initiated 3 weeks post-injection and completed once per week for 5 weeks. Investigators aim to identify what might improve or extend the duration of botox injections for adductor Spasmodic dysphonia.