Perceptual and Acoustic Correlates of DBS of Subthalamic Nucleus versus Globus Pallidus Interna for IPD: A Comparative Pilot Study

Abstract

Purpose: This study compared bilateral deep brain stimulation (DBS) in subthalamic nucleus (STN) versus globus pallidus interna (GPI) on perceived Speech Severity in Parkinson’s disease. Methods: 12 individuals with STN-DBS and 8 individuals with GPI-DBS were audio-recorded with DBS ON and OFF while reading an excerpt from the Rainbow Passage and producing a conversational monologue. Using a within-speaker, paired comparison paradigm, 10 listeners judged Speech Severity for pairs of stimulation ON-OFF (and OFF-ON) reading passages and monologues masked to stimulation status and speaker group. The proportion of trials for which ON versus OFF stimuli in a given pair was judged to be less severe was calculated. Results: There was a task effect, with significant results for Rainbow Passage but not conversational monologue. Perceived Speech Severity differed with stimulation status for GPI-DBS but not STN-DBS, with a greater proportion of ON stimulation speech samples judged to be less severe versus OFF samples. At the participant level, response to ON/OFF stimulation was highly variable in STN-DBS group. Discussion: DBS stimulation differentially impacts perceived speech severity for STN-DBS and GPI-DBS. Results further suggest the perceptual benefit of DBS stimulation may be task specific.

Frits van Brenk

External consultant in the Motor Speech Disorders Laboratory

My research and teaching interests include motor speech disorders, clinical linguistics, experimental psycholinguistics, speech science, and research methods.