Assessing the effectiveness of botulinum toxin injections for adductor spasmodic dysphonia: clinician and patient perception.

To determine the effectiveness of Botox treatment for adductor spasmodic dysphonia (ADSD), the clinician and patient judge changes in voice symptoms and the effect on quality of life. Currently, there is no standard protocol for determining the effectiveness of Botox injections in treating ADSD. Therefore, clinicians use a variety of perceptual scales and patient-based self-assessments to determine patients' impressions of severity and changes after treatments. The purpose of this study was to assess clinician-patient agreement of the effects of Botox on voice quality and quality of life in ADSD. Retrospective chart review of 199 randomly selected patients since 2004. Results indicated a weak correlation between the patient's assessment of voice impairment (EIS) and patient's quality of life impairment (Voice-Related Quality of Life [V-RQOL]) in the mild-moderate dysphonia severity group and the moderate-to-severe dysphonia group. There was a weak correlation between the patient's assessment of voice impairment EIS and the clinician's perceptual judgment of voice impairment (Consensus Auditory Perceptual Evaluation of Voice [CAPE-V]) only in the moderate to severe dysphonia group. There was a weak correlation between the patient's quality of life impairment (V-RQOL) and the clinician's perceptual judgment of voice impairment (CAPE-V) only in the severe to profound dysphonia group. The poor relationship among commonly used outcome measures leads us to question how best to assess the effectiveness of Botox in ADSD. Clinicians are required to document treatment outcomes, making it important to use scales that are valid, reliable, and sensitive to change. Future research directions include examining relationships between measures both before and after Botox injections, examining the specific factors that determine quality of life changes, and further research on specific parameters of the CAPE-V as well as comparing perceptual and quality of life scales with acoustic and aerodynamic measures in this population would be beneficial in the move toward more effective ways of measuring change.