Back     Close

Hemisphere-specific effects of subthalamic DBS on speaking rate and intelligibility of
syllable repetitions in Parkinson's disease

E. Wang, L. Verhagen Metman, R. Bakay, J. Arzbaecher, B. Bernard, and D. Corcos

The study tests the hypothesis that right and left STN DBS have differential effects on speech. Twenty right-handed individuals with advanced PD and dysarthria underwent unilateral STN-DBS. Ten were operated on the right and ten on the left hemisphere. The side receiving STN DBS has more affected motor function. Speech was evaluated before surgery, and three-to-six months after surgery with stimulator-off, and with stimulator-on, all were off anti-parkinsonian medication for 12 hours before evaluation. Evaluators and subjects were blinded to the subjects’ stimulator status at the post-surgery evaluations. Motor performance was assessed with UPDRS-III. Each subject produced 3x3-second samples of diadochokinetic rates. The syllable repetitions were rated for intelligibility using UPDRS-III item 18 and speaking rate ("slow, normal, and fast"). 20 graduate student clinicians served as judges. The samples were randomly presented via headphones. A mixed-two-factor ANOVA with repeated measures was used to assess the significance of the changes in UPRS-III scores and intelligibility and speaking rate. The results indicated unilateral STN-DBS produced improvement in non-speech motor function regardless of the side of STN DBS. In contrast, the effects of unilateral STN-DBS on intelligibility and speaking rate were less impressive and the ST- DBS produced changes that were hemisphere-specific.

Back     Close