Figure 2.

Volume of Tissue Activated as determined from an anatomical model based on imaging data from subjects who have undergone deep brain stimulation (DBS) coupled with finite element modeling (FEM) to calculate the spread of electrical current through the tissue from the active electrode contact. (A) The active contact of each electrode was determined from postoperative programming sessions, and was defined as the cathodal electrode for either monopolar or bipolar stimulation. The active contact is shown on a postoperative computed tomography (CT) scan (left) and on image fusion on magnetic resonance imaging (MRI; right). (B) The volume of tissue activated was calculated from each patient’s specific stimulation parameter settings by using a custom Python-based program from Python libraries. The volume of tissue activated is shown in dark pink alone (left) and in conjunction with the contored nuclei (right). The relevant nuclei were contored and include the thalami (yellow), the red nuclei (red), and the STN (green); the active contact and the volume of tissue activated were also contored (pink). Adapted from Sweet et al. (2014a).