Axial slice from the stereotactic atlas of Morel 3.6 mm ventrally to the AC-PC-level (anterior commissure-posterior commissure). At approximately similar levels in patients the STN can be targeted along a parallel line to the x-axis at the anterior border of the RN. Conductivity values were set to 1.0 S/m for ac, fx, al, ic, mtt, fct, and ml. Bic was attributed with a conductivity of 0.1 S/m, whereas gray matter was attributed with a conductivity of 0.2 S/m. Abbreviations: anterior commissure (ac), fornix (fx), ansa lenticularis (al), internal capsule (ic), mammillothalamic tract (mtt), fasciculus cerebello-thalamicus (fct), medial lemniscus (ml), brachium of the inferior colliculus (bic), medial and lateral geniculate nucleus (MGN and LGN, respectively), pulvinar (Pul), reticular thalamic nucleus (R), globus pallidus internus and externus (GPi and GPe, respectively), putamen (Put), nucleus accumbens (Acb), hypothalamus (Hyp), subthalamic nucleus (STh; the subthalamic nucleus is abbreviated with Sth, whereas the abbreviation STN is more commonly used), red nucleus (RN), periaqueductal (or central) gray (PAG), caudate nucleus (Cd).