Accuracy and Outcomes of KYMERO Robot-Guided Deep Brain Stimulation for Dystonia : Retrospective Cohort Analysis

Deep brain stimulation (DBS) of the internal globus pallidus (GPi) represents the standard treatment for medically refractory dystonia, with clinical efficacy critically dependent on precise electrode placement. While robotic stereotactic systems promise enhanced targeting accuracy, comparative data for dystonia populations remain limited. To compare stereotactic accuracy and clinical outcomes of KYMERO robot-assisted versus conventional frame-based GPi-DBS in dystonia patients.

A single-center, retrospective cohort study compared 35 patients (68 leads) who underwent KYMERO robot-assisted bilateral GPi-DBS (July 2023 to June 2025) with 42 historical controls receiving frame-based procedures (March 2019 to December 2020). All patients had medically refractory primary dystonia. Primary outcomes included stereotactic accuracy (radial and Euclidean error) and 6-month Burke-Fahn-Marsden dystonia rating scale (BFMDRS) motor improvement. Secondary outcomes encompassed response rates, complications, and procedural consistency.

KYMERO robot-assisted DBS achieved significantly superior targeting accuracy compared to frame-based procedures (mean radial error, 0.89±0.30 vs. 1.92±1.20 mm; p<0.001; euclidean error, 1.15±0.38 vs. 2.80±1.56 mm; p<0.001). The proportion of electrodes within 1.5 mm of target was higher in the KYMERO group (94.1% vs. 66.7%, p<0.001), with fewer targeting outliers exceeding 2 mm (2.9% vs. 23.8%). Clinical outcomes were equivalent between groups, with 6-month BFMDRS motor improvement of 66.9%±13.8% for KYMERO versus 64.7%±23.5% for frame-based procedures (p=0.614). Response rates (≥50% improvement) were 85.7% and 78.6%, respectively. Complication rates were low and comparable (5.7% vs. 9.5%). The KYMERO cohort demonstrated reduced outcome variability, suggesting enhanced procedural reproducibility.

KYMERO robot-assisted GPi-DBS achieves significantly superior stereotactic accuracy compared to conventional frame-based approaches while maintaining equivalent clinical efficacy and safety. The enhanced precision and reduced outcome variability support robotic assistance as a valuable advancement for dystonia DBS procedures.