Aerodynamic findings and Voice Handicap Index in Parkinson’s disease

Objective To verify possible relations between vocal disability and aerodynamic measures in selected Parkinson’s disease (PD) patients with low/moderate-grade dysphonia. Methods Fifteen idiopathic dysphonic PD male patients were examined and compared with 15 euphonic subjects. Testing included the following measures: Voice Handicap Index (VHI), maximum phonation time (MPT), mean estimated subglottal pressure (MESGP), mean sound pressure level (MSPL), mean phonatory power (MPP), mean phonatory efficiency (MPE) and mean phonatory resistance (MPR). Results Statistical analysis showed: a significant reduction in MPR and MSPL in PD subjects compared to the healthy ones; a significant positive correlation between VHI score and MSPL, MPR, MPP, MESGP and a significant negative correlation between VHI and MTP within PD subjects. Test for multiple linear regression showed a significant correlation between VHI score, MPT, MPR and MSPL. Conclusions A relationship between VHI and aerodynamic measures was shown in the present study. Compensatory mechanisms may aggravate vocal disability in PD subjects.