Dual-target magnetic resonance–guided focused ultrasound of the subthalamic and ventral intermediate nuclei for Parkinson’s disease: illustrative case

BACKGROUND: Magnetic resonance-guided focused ultrasound (MRgFUS) has emerged as a minimally invasive alternative for medication-refractory Parkinson's disease tremor. While single-target ablation of either the subthalamic nucleus (STN) or the ventral intermediate nucleus (VIM) is standard, intraoperative adaptation to address incomplete symptom relief remains largely unexplored. OBSERVATIONS: The authors present the case of a 70-year-old man with an 8-year history of Parkinson's disease who underwent planned unilateral left STN MRgFUS. Following lesioning, marked improvement in bradykinesia and rigidity was observed; however, residual tremor (approximately 30% of baseline) persisted. Based on intraoperative clinical assessment, an additional VIM lesion was performed within the same session, resulting in complete tremor resolution without adverse effects. LESSONS: This report illustrates the technical feasibility and safety of dual-target MRgFUS for Parkinson's disease, achieved through intraoperative, symptom-guided decision-making. To the authors' knowledge, this represents the first documented case of combined STN and VIM ablation within a single MRgFUS session, highlighting a potential framework for adaptive, multitarget lesioning in functional neurosurgery. https://thejns.org/doi/10.3171/CASE2643.