Event Abstract Back to Event Executive control and deep brain stimulation of the subthalamic nucleus: Inhibition and task switching in the Stroop test A. Ahmed1, S. C. Cooper1, M. Deogaonkar1, D. Floden1*, I. Itin1, C. S. Kubu1 and A. Machado1 1 Cleveland Clinic Foundation, Center for Neurological Restoration, United States The subthalamic nucleus (STN) is a common surgical target in deep brain stimulation (DBS) treatment for the motor symptoms of Parkinson disease. Recent work [1] suggests that the right STN is part of a frontal-subcortical network involved in cognitive inhibition. If so, stimulation of the right STN would be expected to impact cognitive control. We examined performance on the Stroop test in 83 non-demented Parkinson patients. The Stroop test requires inhibition of prepotent responses and this version incorporates control and task switching conditions. Patients completed this measure during pre-surgical DBS evaluations (N=62) or six-month postoperative evaluations after left (9 patients) or bilateral (12 patients) STN DBS. Bilateral patients were younger and this was entered as a covariate into the analyses. The groups did not differ on other demographic or disease variables. Patients with bilateral STN electrodes were comparatively slower and/or error prone on inhibition, switching, and colour naming conditions. There was also a trend toward improved switching performance in the left group. The results are discussed in terms of a putative right-STN role in inhibition, and consequences of DBS for treatment of executive dysfunction in Parkinson disease are considered.