P.124 Subnuclear contact localization within the subthalamic nucleus in deep brain stimulation for Parkinson Disease

Background: Therapeutic response from subthalamic nucleus (STN) deep brain stimulation (DBS) for Parkinson disease (PD) has been associated with proximity to an ideal target, commonly in the dorsal sensorimotor STN. Automated registration and atlas-based segmentation allowed contact localization within STN subnuclei. We sought apply these methods characterize spatial distribution of our active placements. Methods: conducted a retrospective analysis 55 patients who underwent bilateral DBS PD. Post-operative CT/MRI scans were non-linearly registered into standard space, DBS-electrodes localized using Lead-DBS. 3-dimensional meshes segmented atlas (Ewert 2017) utilized. Analysis was performed MATLAB R2019b. Results: Mean contacts bilaterally, located posteroinferiorly compared reported targets. Centroids fell (left/right): (46%/40%), associative (22%/22%), limbic (0%/2%) outside (32%/36%). Principal components demonstrated most variance is explained by first component (left 65.8%, right 61.9%). Conclusions: obtained locations relation subnuclei, allowing anatomically guided approach analysis. 66% STN, variation occurred along single dimension. Future directions include utilizing subnuclei localizations investigate clinical outcomes.