Fig. 1

Illustration of ventral-most active lead location within the subthalamic nucleus (STN). Images were created by fusing the pre-operative MRI with post-operative CT images using BrainLab. The deepest active contacts were marked and identified as white dots (c) in the axial MRI section through the midbrain at the level of the STN and red nuclei. These illustrate the relative position in the mediolateral and anteroposterior directions. d, e, and f demonstrate the deepest active contacts (white arrows pointing to black dots) within the STN by mapping the contacts into the representative slices from the Schaltenbrand and Wahren Atlas within BrainLab. a (axial view), left contact within anteromedial STN. b (axial view), right lead within dorsolateral STN and having a more dorsal position compared to (a). c (coronal view), both active contacts positioned within the dorsal STN