Subthalamic deep brain stimulation for resolving visuo-vestibular conflict in parkinson's disease

The National Institute of Neurological Disorders and Stroke awarded The Cleveland VA Medical Research & Education Foundation $330,000 on August 7, 2026, under the Extramural Research Programs in the Neurosciences and Neurological Disorders program (CFDA 93.853) to investigate subthalamic deep brain stimulation for resolving visuo-vestibular conflict in Parkinson's disease.

The research aims to optimize subthalamic nucleus DBS to enhance self-motion perception and visuo-spatial navigation in Parkinson's disease patients while maintaining effectiveness on motor symptoms. The work employs psychophysics, virtual reality, motion analysis, neuroimaging, and computational modeling to investigate visuo-vestibular interactions and how STN DBS improves perception during visual-vestibular conflicts. Clinical assessments include functional gait assessment, gait disorientation task, gait speed, and motor symptom evaluation using UPDRS-III. Aim 1 examines how the location of tissue activation within the STN affects heading perception during visuo-vestibular conflict using a motion simulator and virtual reality, combined with development of a stimulation atlas identifying STN locations linked to changes in heading perception. Aim 2 identifies which axonal pathways modulated by STN DBS correlate with improved heading perception.

Performance occurs in Cleveland, Ohio. The period of performance runs through July 31, 2031.

Abstract

Parkinson's disease (PD) affects about 10 million people globally, including 1 million americans. Beyond motor symptoms like tremors and rigidity, PD patients often struggle with visuo-spatial navigation, impacting skills such as pathfinding, spatial memory, and awareness, and affecting gait due to difficulties in resolving visuo-vestibular conflicts. These deficits are often unresponsive to conventional pharmacotherapy, making deep brain stimulation (DBS) surgery necessary. Subthalamic nucleus (STN) DBS is preferred for motor symptoms, but its impact on non-motor symptoms like spatial navigation varies. Our research aims to optimize STN DBS to enhance self- motion perception and visuo-spatial navigation in PD while maintaining its effectiveness on motor symptoms. We will investigate visuo-vestibular interactions and how STN DBS improves perception during visual-vestibular conflicts using psychophysics, virtual reality, motion analysis, neuroimaging, and computational modeling. Clinical assessments will include functional gait assessment (FGA), gait disorientation task (GDT), gait speed, and motor symptoms (updrs-III). We hypothesize that STN DBS improves heading perception during visual- vestibular conflict, with favorable effects linked to specific STN regions and pathways. Aim 1 will examine how the location of tissue activation within the STN affects heading perception during visuo-vestibular conflict. We will use a motion simulator and virtual reality to study heading perception under synchronized or conflicted visual and vestibular signals, combined with clinical assessments. We will also test the effects of STN DBS by switching DBS on and off from different electrode contacts and create a stimulation atlas to identify STN locations linked to changes in heading perception. Aim 2 will identify which axonal pathways modulated by STN DBS correlate with changes in heading perception during visuo-vestibular interaction. We will combine patient-specific vtas with tractography to pinpoint white-matter pathways that correlate with changes in heading perception. We hypothesize that hyperdirect pathway stimulation will improve heading perception, while cerebello-thalamic pathway stimulation will worsen IT. This research aims to improve treatment for navigational and balance impairments in PD, enhancing clinical outcomes and deepening our understanding of the role of basal ganglia in motion perception.