Vocal symptoms and acoustic changes in relation to the expanded disability status scale, duration and stage of disease in patients with multiple sclerosis.

Vocal symptoms and acoustic measures of patients with multiple sclerosis (MS) are investigated in relation to the duration of the disease, stage of the disease and the degree of disability. Eighty-two patients were enrolled in this study (40 MS, 42 controls). In the MS group, the most common vocal symptoms were vocal breaks and vocal fatigue present in 10. None of the patients in the control group had voice breaks. In the male group, there was a significant decrease in the fundamental frequency, habitual pitch and maximum phonation time with a significant increase in Shimmer. In the female group, there was a significant decrease in the maximum phonation time only. There was no correlation between vocal symptoms and acoustic measures versus duration of the disease and extent of disability except for vocal fatigue which significantly associated with EDSS (expanded disability status scale) score. Patients with MS may develop vocal symptoms irrespective of the EDSS score, duration and stage of the disease. Vocal fatigue and vocal breaks are more common than hoarseness.