Professor Noam Harel

Deep brain stimulation (DBS) is a surgical procedure used to treat various neurological and neuropsychiatric disorders, including Parkinson’s disease, essential tremor, dystonia, and obsessive-compulsive disorder. To date, over 100,000 patients worldwide have undergone DBS surgery, and this number is expected to increase significantly. DBS involves the surgical implantation of an electrode into a specific brain target, for delivery of electrical stimulation, alleviating disease symptoms. However, one of the ambiguities of this procedure is that the clinical outcomes can vary greatly across patients. One plausible explanation for the differences may lie in unoptimized DBS lead placement and the stimulation of undesired anatomical structures and white-matter pathways. Thus, the success of this surgical technique is critically dependent on the precise placement of the DBS electrode. At present, DBS surgery relies on a two-step procedure: initial target localization is based on stereotactic imaging combined with cadaveric atlas-derived consensus coordinates. However, current clinical imaging methods do not allow for a clear visualization of DBS target structures, which can result in electrode placement errors. Consequently, this step is followed by an invasive microelectrode recording procedure that is used for target validation, but carries risk.

This project aims to improve the imaging-based target localization and visualizations for DBS surgery. Capitalizing on the advantages of high-field (7 Tesla) MRI, combined with several image post-processing and visualization techniques, these researchers will develop a patient-specific 3D volumetric model of the DBS target, the surrounding white matter tracks, and the neighboring structures. These unique imaging and visualization capabilities will provide unparalleled anatomical and connectivity characterization of each patient. This work is innovative in that it will bring state of the art imaging techniques into a clinical setting – a clear example of translation and implementation of cutting edge basic science methods into the clinical realm. By merging the information obtained via each imaging approach, a comprehensive, patient-specific, 3D model of each patient’s target area will be generated. Each anatomical model will include the DBS target structure of interest, adjacent white matter bundles, as well as along the intended trajectory of the DBS electrode. In addition to the pre-surgery patient-specific anatomical model, a postoperative CT image will be obtained and co-registered to preoperative MR images, including the final electrode location into the model.