Voice Related Quality of Life in Spasmodic Dysphonia : Treatment Effects and Correlation with Voice Assessment

Spasmodic Dysphonia (SD) patients (adductor type) are known to score very high on the Voice Handicap Index (VHI). 28 VHIanalyses were performed in patients diagnosed with spasmodic dysphonia (SD), before and after treatment with botulinum toxin. Patient’s voices were also analyzed perceptually and acoustically : 7 perceptual parameters (traditional and dedicated) were blindly rated by a panel of 3 experienced speech therapists and 9 acoustic measures (mainly based on voicing evidence and periodicity) were achieved by a special analysis program suited for strongly irregular signals. After treatment, the average VHI total score is reduced by 15.41 points (from 64,17 to 48,75), which may be considered as clinically relevant for a group design. A paired comparison pre/post also demonstrates a significant improvement in voice-related quality of life (p = .039). The effect size is to be considered as medium to large (Cohen’s d = .7). However, as well in preas in post-situation, there is no significant correlation between the VHI score and either the perceptual ratings or the acoustic measurements. Even the pre-/post differences in perception, acoustics or VHI do not correlate with each other. This points out that the patient’s self-evaluation is a different dimension from the perceptual and the physical ones.