Deep brain stimulation in Parkinson's disease: a comparison of accuracy and clinical outcomes of frame-based, frameless and frameless fiducial-less techniques

Background: The effectiveness of deep brain stimulation (DBS) for Parkinson's disease (PD) depends on implantation accuracy. DBS initially employed a stereotactic frame (frame-based, FB), but technological advancements led to the development of less invasive methods based on fiducial markers (F + F) or intraoperative imaging (F-F). This study compares the accuracy and efficacy of three DBS-STN implantation techniques. Methods: This retrospective study involved 18 patients with PD who underwent bilateral STN DBS between 2018 and 2023. Patients were divided into three groups: FB (n = 6), F + F (n = 7), and F-F (n = 5). Postoperative CT and preoperative MRI fusion were used to evaluate electrode accuracy via deviations from planned targets in x, y, z axes, and calculate the radial error (RE) and vector error (VE). We analyzed Unified Parkinson's Disease Rating Scale (UPDRS) III scores in four "on/off medication-stimulation" combinations, LEDD, and disease stage before DBS, and 3 and 12 months post-DBS. Results: No statistically significant differences were observed between the three methods in|Δx| (FB = 1.30 ± 0.91; F + F = 1.05 ± 0.93; F-F = 1.33 ± 1.09 mm),|Δy| (FB = 0.95 ± 0.98; F + F = 1.11 ± 1.17; F-F = 1.28 ± 1.14 mm), RE (FB = 1.82 ± 0.29; F + F = 1,71 ± 0,36; F-F = 1,91 ± 1,49 mm) and VE (FB = 3,14 ± 0,35 mm; F + F = 4,92 ± 0,54 mm; F-F = 4,42 ± 1,22 mm). All groups demonstrated significant UPDRS III (> 50%) and LEDD reduction (> 40%) at 12 months, with no intergroup differences. Conclusions: The study concludes that all three techniques provide equivalent accuracy and clinical efficacy. Centers should select DBS-STN methods based on available resources and expertise.