Subthalamic nucleus (STN) has been extensively reported in the literature to be the optimal target for the treatment of Parkinson’s disease using Deep Brain Stimulation (DBS). However, due to its poor visibility on conventional imaging and potential brain shift issues some centers use muscular contraction due to stimulation of the internal capsule to find the optimal target.

     In this study, we used non-rigid image registration to create statistical maps of contraction and intra-operative implant positions to study their correlation with the anatomy.

     We collected 216 contraction stimulation response points as well as the location of the mid-point of the Intra-Operative Implant Position (IIP) in 18 STN-DBS implantations over the last year at Ohio State University.

     These were added to the CranialVault atlas at Vanderbilt University. The pre-operative MRIs were non-rigidly registered to an atlas MRI to project data from each patient onto the atlas. Probabilistic maps of contraction and the IIPs were created and overlaid on the ICBM152 template, and the histological atlas developed by Yelnik and colleagues from Paris.

     Our results show that the high probability region of the map of the IIPs lies inside the STN just inferior to ZI while that of the contraction map lies inside the internal capsule proximal to its border with the dorsal part of the STN. The posterior, lateral and superior stereotactic coordinates of the high probability centers of the IIP and contraction maps are (0.4, 13.3, -1.1) and (0.7, 15.4, -1.5) respectively.

     This is a retrospective study.

     Our probabilistic maps of contraction and IIPs correlate well with the anatomy.

     This could help validate our atlas and our maps for use towards computer-based assistance during the various stages of DBS in the future.