Anatomical Determinants of STN Coordinate Shift in Idiopathic Parkinson's Disease DBS Surgery.

Objective: This study examines how anatomical variations influence the targeting coordinates of the subthalamic nucleus (STN) in patients with Idiopathic Parkinson's Disease (IPD) undergoing Deep Brain Stimulation (DBS), with the goal of enhancing targeting accuracy.

Methods: A retrospective analysis was performed on 202 STNs from patients who received bilateral STN-DBS surgery. Pre- and postoperative imaging data were used to determine accurate STN coordinates, while brain volume measurements, ventricle size, Evans Index, and AC -PC length were analyzed. Atrophy grading scales were also applied. Correlation and regression analyses assessed the relationship between the STN target location and all anatomical parameters on the x, y, and z axes.

Results: Age showed a significant positive correlation with lateral STN coordinate shift on the x-axis, with each additional year leading to a 0.046 mm shift. An increase in peripheral gray matter volume and a decrease in white matter volume were significantly associated with the lateral displacement of the STN. Total ventricle volume demonstrated a positive correlation with STN shift on both the x-axis (0.0227 mm per cm3 increase) and z-axis (0.0087 mm per cm3 increase). Significant correlations were also found for the Evans Index with lateral shift on the x-axis and for AC-PC length with vertical shifts.

Conclusions: Anatomical factors, such as brain volume, ventricle size, Evans Index, AC-PC length, and atrophy scores, significantly influence STN localization in PD patients undergoing DBS. Accounting for these shifts during surgical planning may improve electrode placement accuracy and enhance therapeutic outcomes, underscoring the importance of personalized targeting strategies.