BACKGROUND: Dysphonia is common in Parkinson's disease (PD), but the mechanism underlying the development remains unclear. This study investigated possible clinical factors related to PD dysphonia.
METHODS: Dysphonia severity was assessed in 147 non-demented patients with PD and 30 non-PD controls using the Voice Handicap Index (VHI)-10. A threshold of 12 VHI-10 score was used to define the presence of dysphonia. The severity of PD and depression was measured using the Unified Parkinson's Disease Rating Scale (UPDRS)-motor and the Geriatric Depression Scale (GDS).
RESULTS: Dysphonia was observed in 52 patients (35.4%). Patients with dysphonia scored higher on the UPDRS and GDS scores compared with patients without dysphonia. Multivariate logistic regression analysis revealed that GDS was the only factor significantly associated with the presence of dysphonia. Non-PD controls did not show this association.
CONCLUSIONS: The results support a high prevalence of dysphonia in patients with PD, and suggest that the presence of dysphonia is more closely related to depression than to the severity of PD.