Effect of deep brain stimulation on speech in patients with Parkinson’s disease

Presented at the XVIII Congress of the European Society for Stereotactic and Functional Neurosurgery, Rimini, Italy, 5–8 October 2008

Papathanasiou I,1 Protopapas A,2 Deligiorgi G,1 Lolakidi A,1 Kasselimis D,3 Themistocleous M,4 Boviatsis E,4 & Sakkas D4
1 Department of Speech & Language Therapy, TEI Patras Greece
2 Institute for Language & Speech Processing / Athena, Greece
3 Department of Psychology, University of Crete, Greece
4 Department of Neurosurgery, Medical School, University of Athens, Greece

In this presentation we report the preliminary results of seven cases patients with PD before and six months after surgical STN-DBS treatment, where we study in detail the acoustic properties of their speech in relation with articulatory and other cognitive motor executive tasks.

Method: Seven patients with PD (N= 7, mean age= 68.3 years), were assessed 3 days before the surgical procedure “on medication” state and six months post operation “on stimulation” state. The assessment protocol consisted of the Greek version of Frenchay Dysarthria Assessment (FDA), sustained phonation, reading words and text, and a monologue, a motor time reaction task, a speech/ phonation reaction task and a cognitive executive function construction task. For the analysis of the recorded data we used the Praat program. For the statistical analysis the Wilcoxon Signed Ranks Test was used.

Results: There were no significance differences in any tasks of the articulatory functions, the speech rate during reading in speaking and the acoustic measures which were evaluated with our protocol. However, there was a significant delay in the speech/phonation reaction time in the post operation condition comparing to the before operation condition (z=2,201, p=0.016) but not in the motor reaction task or in the other cognitive executive task.

Discussion: Our data from seven patients demonstrated that there were no significant changes in the articulatory, speech and acoustic properties of speech in PD patients who have undergone STN- DBS treatment to improve their motor function, however, cognitive tasks related to speech have changed.