Functional Outcomes and Quality of Life after unilateral MRgFUS Subthalamotomy in Parkinson’s Disease

INTRODUCTION: Parkinson's disease (PD) leads to progressive motor and non-motor deficits that compromise activities of daily living (ADL) and quality of life (QoL). Although bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) is highly effective, its invasiveness restricts use in certain patients. Magnetic resonance-guided focused ultrasound (MRgFUS) subthalamotomy offers a less invasive, lesion-based alternative, but evidence regarding its broader functional impact remains limited. OBJECTIVE: To assess the effects of unilateral MRgFUS subthalamotomy on motor experiences of daily living (MDS-UPDRS II) and QoL (PDQ-39) in patients with PD. METHODS: Thirty patients with asymmetric PD refractory to optimized dopaminergic therapy underwent unilateral MRgFUS subthalamotomy targeting the dorsolateral STN between June 2021 and June 2024. Evaluations were performed at baseline, 6, and 12 months using MDS-UPDRS II-III, PDQ-39, EQ-5D, and Berg Balance Scale. Primary endpoints were changes in MDS-UPDRS II and QoL; secondary outcomes included motor function (MDS UPDRS III), levodopa equivalent daily dose (LEDD), and safety. RESULTS: Off- and On-state MDS-UPDRS II improved by 38.5% and 45.8% at 6 months (p<0.01) and by 50% in both states at 12 months (p<0.01). PDQ-39 ADL subdomain improved by 10.4% at 12 months (p=0.033), while global QoL indices remained stable. Off-state motor scores improved by 35.9% (p<0.001), with reductions in rigidity (50%), bradykinesia (52.9%), and tremor (81.7%). LEDD decreased by 22.1% (p=0.003). Adverse events were mild and transient, including dysarthria, facial asymmetry, and gait disturbance. CONCLUSION: Unilateral MRgFUS subthalamotomy was associated with improvements in motor function and motor-related activities of daily living, with a favorable safety profile. These findings suggest that this approach may represent a potential less invasive therapeutic option for selected patients who are unsuitable for or unwilling to undergo DBS, although results should be interpreted with caution given the study design.