A-190 Posterior Electrode Angle Predicts Post-DBS Apathy Increases in Parkinson’s Disease Patients

Abstract

Abstract Objective: The literature has consistently shown that Parkinson’s disease (PD) patients tend to experience increases in apathy following deep brain stimulation of the subthalamic nucleus (STN-DBS). While surgical variables, i.e., active contact location and lead angle, have previously been found to predict post-DBS cognitive changes, it has yet to be studied whether these variables also impact post-DBS apathy. Method: Data was retrospectively analyzed from 42 individuals with idiopathic PD who underwent bilateral STN-DBS. Forty-two individuals completed patient-report versions of the Marin Apathy Scale, and 27 had accompanying caregiver reports. Pearson’s correlations and linear regressions were conducted to examine the impact of active contact location (in X, Y, and Z axes) and lead angle (in anterior/posterior and medial/lateral directions) on post-DBS apathy changes. Covariates included disease duration, age, and change in motor symptoms (as measured by the MDS-UPDRS). Results: Increases in caregiver-reported apathy post-DBS were explained by more posterior angles of the leads in both hemispheres (right: R2 = .33, F(3,23) = 3.79, p = .02, sr2 = .32; left: R2 = .37, F(3,23) = 4.56, p = .01, sr2 = .36). Although a significant correlation was identified between worse patient-reported apathy and more medial active contact location in the right hemisphere, this effect was no longer significant with inclusion of covariates. Conclusions: Findings indicate that lead angle, but not active contact location, has a significant impact on post-DBS increase in apathy. This is consistent with prior studies predicting post-DBS verbal fluency changes and may suggest an adverse effect on frontostriatal neurocircuitry.