English: 3D anatomical relationship between subcortical nuclei, and active contacts for models I–IV. The subthalamic nucleus (STN) is shown in green, while the thalamus is shown in yellow. For models I and II, the DBS electrode was placed in the posterolateral STN. For models III and IV, the electrode was shifted by 4 mm to a more anteromedial portion of the STN. The numbers I-IV indicate the selection of the active contact (cathode) for each of the four models. The inset in the upper right corner illustrates the consecutive numbering of the contact labels. Contact 2 was selected for monopolar stimulation in models I and IV, while contact 0 was selected for monopolar stimulation in models II and III. A, anterior; P, posterior; R, right; L, Left; D, dorsal; V, ventral.