Publication date: Jan 18, 2025

Magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy of ventral intermediate (Vim) nucleus is useful to treat drug-resistant tremor-dominant Parkinson’s disease (TdPD), but tremor relapse may occur. Predictors of relapse have been poorly investigated so far. The aim of this study is to evaluate the role of clinico-demographic, procedural, and neuroradiological variables in determining clinical response, relapse, and adverse events (AEs) in TdPD after MRgFUS Vim-thalamotomy. Fifty-two TdPD patients who consecutively underwent unilateral MRgFUS Vim-thalamotomy were prospectively evaluated at baseline and after 24 hours, 1 month, 6 months, and 12 months using MDS-UPDRS-III in off and on medication conditions. AEs were collected at each evaluation. Lesion volume was calculated at 24-hour magnetic resonance imaging (MRI). Patients with tremor improvement 30% at 24 hours. Tremor relapse occurred in 12 patients (23%), exclusively during the first month after thalamotomy. Relapse was associated with younger age (P = 0. 030) and smaller lesion volume (P = 0. 030). At 1 month, 22 patients (42%) had AEs; at 6 and 12 months, AEs persisted in 19% and 6% of cases. AEs at 6 months were associated with larger lesions (P = 0. 018). All AEs were mild. MRgFUS Vim-thalamotomy is effective in treating tremor in TdPD. Relapse is associated with younger age and smaller lesion volume, but larger lesions make AEs more likely to persist. We suggest that a lesion volume between 145 and 220 mm on T1-weighted MRI may be the therapeutic window that ensures tremor control without long-lasting AEs. (c) 2025 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Semantics

Original Article