Unilateral Stimulation of Subthalamic Nucleus Does Not Affect Inhibitory Control

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neurology

Background:

• Inhibitory control is crucial for behavior, but its neural basis is debated.
• The right subthalamic nucleus (STN) has been implicated in a right-lateralized inhibitory control network.

Purpose of the Study:

• To investigate the role of the STN in inhibitory control using unilateral deep-brain stimulation (DBS).
• To assess the impact of unilateral STN DBS on reactive and proactive inhibition in Parkinson's disease patients.

Main Methods:

• Studied 20 Parkinson's patients with unilateral STN DBS (left or right) and 22 healthy controls.
• Administered a stop-signal reaching task comparing DBS-ON and DBS-OFF conditions.
• Compared patient performance to age-matched healthy participants.

Main Results:

• Parkinson's patients exhibited impaired inhibitory control compared to healthy individuals.
• Unilateral STN DBS (left or right) did not significantly improve reactive or proactive inhibition.
• Previous studies showed bilateral STN DBS restores near-normal inhibitory control.

Conclusions:

• The right STN alone does not appear critical for suppressing actions.
• Both subthalamic nuclei (STN) likely need simultaneous activation for optimal inhibitory control.
• Bilateral STN DBS may be more beneficial than unilateral DBS for improving inhibitory control in Parkinson's disease.