To compare motor outcomes associated with two distinct surgical methods employed by neurosurgeons at a single institution where intraoperative monitoring and programming were conducted by the same team.

Deep Brain Stimulation of the Subthalamic Nucleus (DBS-STN) is a well-established treatment for managing Parkinson disease (PD) patients¹. Precise targeting of the STN is crucial to achieve optimal outcomes^{2 3,4}. Whether altering the planned trajectory affects motor outcomes remains unclear in PD patients who might have structural brain changes⁵.

We conducted a retrospective analysis of PD patients with bilateral STN-DBS at WashU Medicine between 2007–2017. Surgeon 1 employed trajectory refinement based on intracranial anatomy while Surgeon 2 employed a skull-based anatomical approach independent of intracranial anatomy.  We sampled 95 patients in a pseudo-random temporally matched fashion. Primary outcome was ≥30% reduction in off medication UPDRS-III scores, averaged over 12 months postoperatively. Analyses included t-tests and logistic regression models adjusted for demographic and clinical covariates.

Primary outcome proportion of motor improvement > 30% was similar between Surgeon 1 and Surgeon 2 groups (p = 0.88). Binary logistic regression adjusting for confounders, including age at surgery, sex, disease duration, levodopa equivalent daily dose (LEDD), handedness, and Evans Index, revealed no significant association between surgeon group and motor response. Postoperative LEDD was reduced in both groups compared to baseline, but reduction was significantly greater in the group2 (P= 0.002).

Both intracranial anatomy–based and skull landmark–based surgical approaches result in comparable motor outcomes after STN-DBS. More LEDD reduction was noted in group 2. This should be interpreted with caution as it may reflect center-specific or patient-specific factors rather than a true advantage of the technique, considering the small sample size.We plan to compare groups adverse event rate to better explore the differences between two surgical methods.