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Updated: Jun 13, 2026
MRI-guided Focused Ultrasound Thalamotomy for Patients with Medically-refractory Essential Tremor
Published on: December 13, 2017
Outcomes of Bilateral Deep Brain Stimulation After Magnetic Resonance‑Guided Focused Ultrasound Thalamotomy: A Case
Andrea C Zoana1, Mitesh P Lotia1,2, Nigam A Reddy2
1AdventHealth Neuroscience Institute, Orlando, Florida, USA.
Background And Objectives:
Despite its efficacy in treating medically refractory movement disorders, magnetic resonance‑guided focused ultrasound (MRgFUS) thalamotomy may result in tremor recurrence, requiring additional interventions. The aim of this study was to evaluate the safety and efficacy of subsequent deep brain stimulation (DBS) as a management strategy for patients with recurrent or residual symptoms after MRgFUS thalamotomy.
Methods:
We retrospectively reviewed 8 patients who underwent bilateral DBS after unilateral MRgFUS thalamotomy for medically refractory essential tremor (n = 7) or tremor-dominant Parkinson disease (n = 1) between January 2021 and August 2025. During this time frame, we performed 529 MRgFUS thalamotomies in 461 patients and 108 DBS procedures in 100 patients. We analyzed clinical indications, complications, and functional outcomes using the Fahn-Tolosa-Marin (FTM) Tremor Rating Scale and the Unified Parkinson's Disease Rating Scale Part III.
Results:
The mean time from MRgFUS to bilateral DBS was 19.2 months (range: 6-48 months). Indications for DBS included tremor recurrence (n = 4), technical inability to complete MRgFUS ablation because of anatomical limitation (n = 2), and progression of contralateral symptoms (n = 2). All patients tolerated the DBS procedure well. Postoperative functional outcomes were favorable, with FTM scores in available cases improving from a mean pre-DBS score of 52.3 to 15.3 (mean FTM reduction of 70.7%). The patient with tremor-dominant Parkinson disease experienced a reduction of 64.9% in the Unified Parkinson's Disease Rating Scale Part III OFF score, improving from 57 before DBS to 20.
Conclusion:
Prior unilateral MRgFUS thalamotomy does not limit the safety and effectiveness of subsequent bilateral DBS. DBS serves as a viable treatment option in case of suboptimal MRgFUS outcomes, providing adjustable therapy and a flexible approach for managing progressive disease. In some patients, the residual MRgFUS lesion may enhance DBS efficacy, allowing adequate tremor control at lower ipsilateral stimulation thresholds.
