Deep Brain Stimulation of the Subthalamic Nucleus in Parkinson's Disease: Usefulness of Intraoperative Radiological Guidance The Stereoplan

Background: In our stereotactic procedure, intraoperative radiological documentation of electrode localization is performed using the Stereoplan. The aim of the study was to evaluate its accuracy. Patients and Methods: Data of 20 consecutive patients, treated for Parkinson's disease by implantation of deep brain stimulators into the subthalamic nucleus, were collected prospectively. During surgery, Stereoplan coordinates of the tip of the central macroelectrodes were compared with intended coordinates along the central trajectory at 4 levels: (1) 10 mm above the anatomical target, (2) in the target, (3) in the substantia nigra pars reticulata, and (4) at the depth of contact 1. Before the frame's removal, Stereoplan coordinates of the contacts of the definitive electrode were compared with postoperative MRI coordinates. The mean of the differences was calculated in the x-, y-, and z-axis. Clinical results at 6 months were recorded. Results: The mean of the differences between Stereoplan coordinates and intended coordinates for the macroelectrodes was lower than 1 mm. A submillimeter difference was also found for the definitive contacts. At 6 months, the Unified Parkinson's Disease Rating Scale III score improved by 70.6% compared with the baseline score. Dyskinesia and motor fluctuations decreased by 85.7 and 87%, respectively (p < 0.0001). Conclusion: Stereoplan could be considered an accurate intraoperative radiological system which assures the correct position of the electrode in the anatomical target. Copyright (C) 2008 S. Karger AG, Basel