Subthalamic Nucleus Deep Brain Stimulation for Parkinson’s Disease: Magnetic Resonance Imaging Targeting Using Visible Anatomical Landmarks

Background: The aim of the present study was to validate a magnetic resonance imaging (MRI) visual procedure to target the subthalamic nucleus (STN) based on surrounding anatomical landmarks. Methods: 31 consecutive bilaterally implanted parkinsonian patients were included in this study. After identification of the anterior commissure (AC), posterior commissure (PC) and midcommissural point on a three-dimensional T1-weighted sequence, inversion recovery (IR) T2-weighted coronal slices were performed orthogonal to the AC-PC line. On the slice showing the anterior pole of the red nucleus (RN), the target was placed in the inferolateral portion of the subthalamic zone, limited superiorly by the thalamus, laterally by the internal capsule, inferiorly by the substantia nigra and medially by the midline. The distribution of the targets was analyzed in the AC-PC referential. Results: The mean target coordinates were as follows: anteroposterior (AP) = –2.54 mm (±1.37 mm), lateral (LAT) = 12.03 mm (±0.91 mm) and vertical (VERT) = –6.10 mm (±1.52 mm) for the right side, and AP = –2.65 mm (±1.36 mm), LAT = –11.97 mm (±1.30 mm) and VERT = –5.89 mm (±1.52 mm) for the left side. They projected in the inferior portion of the STN on the Schaltenbrand and Wahren atlas [Stuttgart, Thieme, 1977]. Conclusion: Identification of the anterior pole of the RN and the subthalamic zone on coronal IR T2-weighted MRI performed orthogonal to the AC-PC line provides a precise visual procedure to target the STN.