Surgical implantation of STN-DBS leads using intraoperative MRI guidance: technique, accuracy, and clinical benefit at 1-year follow-up.

Background: Improvement of surgical accuracy during DBS-lead implantation has been described recently, leading to "frameless" or "MRI-verified" techniques. However, combining a high-quality definition of the STN using intraoperative 1.5 MRI with the possibility to reduce errors due to co-registration and to monitor lead progression during surgical insertion while checking the absence of surgical complication is an appealing method. We report here surgical methodology, safety, application accuracy, and clinical benefit of STN-lead implantation under MRI guidance.

Methods: Two patients with a severe PD state were treated by bilateral STN-DBS. Leads were implanted under general anesthesia using intraoperative MRI guidance (ClearPoint system). Lead implantation accuracy was measured on T1 axial images at the level of the target. Clinical improvement was measured on the pre- and post-UPDRS 3 scale at 1-year follow-up.

Results: Surgery was safe and uneventful in both cases. Radial error was 0.36 (right) and 0.86 mm (left) in case 1, and 0.41 (right) and 0.14 mm (left) in case 2. No edema or hemorrhage were noticed.

Conclusions: Intraoperative MRI guidance allows DBS lead implantation with high accuracy and with great clinical efficacy. A larger cohort of patients is needed to confirm these initial results.