Subthalamic deep brain stimulation affects heading perception in Parkinson's disease

Area of Science:

• Neuroscience
• Neurology
• Human Perception

Background:

• Parkinson's disease (PD) is characterized by visuospatial impairments and falls.
• Understanding how subthalamic deep brain stimulation (STN DBS) affects visuospatial perception is crucial for PD management.
• The specific impact of STN DBS on visual versus vestibular perception of motion requires further investigation.

Purpose of the Study:

• To investigate the differential effects of STN DBS on visual and vestibular perception of linear motion (heading) in Parkinson's disease patients.
• To determine if these effects are specific to the modulated subthalamic nucleus (STN) location.
• To compare visuospatial perception in PD patients with STN DBS to healthy controls.

Main Methods:

• Employed a two-alternative forced-choice paradigm in 14 PD patients with bilateral STN DBS and 19 healthy controls (HC).
• Utilized immersive virtual reality to present passive en bloc linear motion and 3D optic-flow stimuli.
• Measured vestibular and visual heading perception using psychometric functions (Weibull) to assess accuracy and discrimination thresholds.

Main Results:

• PD patients exhibited significantly lower accuracy and higher thresholds in vestibular heading perception compared to HC.
• STN DBS significantly improved vestibular discrimination accuracy and reduced thresholds in the rightward direction.
• No significant effects of STN DBS were observed on visual heading perception accuracy or discrimination thresholds.
• Patient-specific models linked improvements in vestibular perception to modulation of the dorsal STN.

Conclusions:

• STN DBS demonstrates differential effects on vestibular and visual heading perception in Parkinson's disease.
• The dorsal STN appears to be a key area through which STN DBS influences vestibular heading perception, potentially via cerebellar pathways.
• These findings highlight the complex modulation of visuospatial processing by STN DBS in PD.