Coordinate-based lead location does not predict Parkinson's disease deep brain stimulation outcome

Area of Science:

• Neurosurgery
• Neurology
• Biomedical Engineering

Background:

• Deep brain stimulation (DBS) is a well-established therapy for Parkinson's disease (PD).
• Effective target regions for DBS in PD are known, but predicting outcomes based on lead placement is complex.
• Individual neuroanatomical variations may limit the predictability of simple coordinate-based lead localization.

Purpose of the Study:

• To investigate if Cartesian coordinates of implanted DBS leads predict motor outcomes in Parkinson's disease patients.
• To test the hypothesis that lead position and trajectory relative to the mid-commissural point (MCP) significantly correlate with clinical outcomes.
• To evaluate the reliability of standard lead localization methods in the context of individual patient anatomy.

Main Methods:

• Analysis of 55 subthalamic nucleus (STN) DBS and 41 globus pallidus internus (GPi) DBS patient cohorts.
• Measurement of lead locations in AC-PC space (x, y, z coordinates, entry angles) using CT-MRI fused images.
• Correlation analysis between coordinate-based lead locations and motor outcomes assessed by the Unified Parkinson's Disease Rating Scale (UPDRS).

Main Results:

• Coordinate-based lead locations were not significant predictors of UPDRS III motor score improvement.
• A statistical trend suggested that more anterior GPi lead locations correlated with worse motor outcomes (p<0.082).
• Simple positional measurements of DBS leads did not significantly correlate with motor improvements.

Conclusions:

• Standard DBS lead position relative to the MCP does not reliably predict motor outcomes in Parkinson's disease.
• The lack of correlation is likely due to failure to account for individual neuroanatomical variability.
• More sophisticated methods are needed to precisely identify stimulation locations relative to specific anatomical targets for improved DBS efficacy.