Electrode position and cognitive outcome following deep brain stimulation surgery

Area of Science:

• Neuroscience
• Neurosurgery
• Neurology

Background:

• Deep brain stimulation (DBS) effectively manages Parkinson's disease (PD) motor symptoms.
• Subthalamic nucleus (STN) and globus pallidus internus (GPI) are common DBS targets.
• Cognitive and psychiatric changes can occur post-DBS, complicating outcome assessment.

Purpose of the Study:

• To investigate the association between electrode position and neurocognitive changes after STN and GPI DBS in PD patients.
• To differentiate cognitive effects of STN DBS versus GPI DBS.
• To identify factors influencing cognitive decline post-DBS.

Main Methods:

• Retrospective cohort study of 130 PD patients undergoing DBS (2008-2019).
• Assessed cognitive and psychiatric outcomes including BDI-II, ICB, MMSE, and cognitive status.
• Used statistical tests (Wilcoxon, t-tests, chi-square) for pre- vs. postoperative and comparative analyses.

Main Results:

• Postoperative follow-up showed improved ICB but declined MMSE scores and overall cognitive status.
• STN DBS was linked to a greater decline in cognitive status compared to GPI DBS.
• Medial electrode position correlated with cognitive decline specifically in STN DBS patients.

Conclusions:

• Cognitive changes occur after both GPI and STN DBS, partly due to PD progression.
• STN DBS is associated with a higher risk of cognitive decline than GPI DBS.
• Medial electrode placement in STN DBS may contribute to cognitive decline, suggesting nonmotor pathway involvement.