Single-case report demonstrating technical feasibility and safety of intraoperative, symptom-guided dual-target (STN + VIM) MRgFUS ablation in Parkinson's disease, resulting in complete tremor resolution in one patient.

This is clinically informative for adaptive functional neurosurgery and symptom control strategies but provides minimal mechanistic or therapeutic-discovery insights for drug development, highlighting need for larger studies to assess efficacy and safety.

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.