Outcomes of botulinum toxin treatment for patients with spasmodic dysphonia

Background: Spasmodic dysphonia (SD) is a focal dystonia of the larynx. Although individuals with SD have variable degrees of difficulty in everyday communication and speaking, many report significant impairments. The impact of SD on the quality of life of people with the disorder has not been well measured. Objectives: To assess the impact of SD using a voice-specific, validated outcomes instrument, the Voice Handicap Index (VHI), and to evaluate the effect of botulinum toxin treatment on quality of life. Methods: The VHI measures 3 subscales (physical, functional, and emotional) of impact of a voice disorder as well as a total impact score. The VHI was completed by 30 consecutive patients with SD before receiving botulinum toxin injection and 2 to 4 weeks after injection. Pretreatment scores on the VHI were compared with posttreatment scores. Results: Pretreatment scores on the VHI showed significant impairment in all 3 subscales (physical, 25.5; functional, 21.4; and emotional, 20.4) and the total score (67.6). Statistically significant improvements occurred in all 3 subscale scores and the total score (P=.001) for the 22 patients who completed the posttreatment survey. Conclusions: Spasmodic dysphonia has a significant impact on patients' perception of quality of life as measured by the VHI. Significant improvements in all 3 subscale scores and the total score on the VHI occur after treatment with botulinum toxin.