Comparative Evaluation of Magnetic Resonance-Guided Focused Ultrasound Surgery for Essential Tremor

Abstract

Background: Treatment options for patients with drug-resistant essential tremor (ET) are limited. Magnetic resonance-guided focused ultrasound surgery (MRgFUS) is an emerging technique to treat refractory ET. Objectives: To present MRgFUS as an alternative to radiofrequency (RF) thalamotomy or deep brain stimulation (DBS) for ET treatment. Methods: We retrospectively analyzed 59 patients who underwent unilateral surgery for drug-resistant ET. Treatments included RF thalamotomy (n = 17), DBS (n = 19), and MRgFUS (n = 23). The outcomes measured were tremor severity and treatment-related complications. Results: At 1 month postoperatively, 100% of RF thalamotomy patients, 89.5% of DBS patients, and 91.3% of MRgFUS patients exhibited absent/mild tremor (successful treatment); other patients exhibited partial relief. At 12 months postoperatively, treatment success for each procedure was observed in 70.6, 84.2, and 78.3% of patients, respectively. At 1 month postoperatively, treatment-related complications had occurred in 58.8, 5.3, and 13.0% of patients, respectively. At 12 months postoperatively, side effects persisted in 11.8, 21.1, and 4.4% of patients, respectively. No statistical differences in treatment success were observed between treatments or over time. Complication rates differed between treatment modalities (p < 0.01) and were lowest in the MRgFUS group. Conclusions: Patients with drug-resistant ET received equivalent results from RF thalamotomy, DBS, and MRgFUS. DBS and MRgFUS resulted in fewer treatment-related complications.

A meta-analysis of outcomes and complications of magnetic resonance–guided focused ultrasound in the treatment of essential tremor

“…All the studies demonstrated a good improvement in the total tremor scores and the subsections of the CRST scores. 4,9,15,19,22,32,36,38 Our analysis showed a significant improvement of CRST Total scores, CRST Part A scores, CRST Part C scores, and QUEST scores by 62.2%, 62.4%, 69.1%, and 46.5%, respectively. The study by Elias et al, 9 which included 56 patients, was the only RCT.…”

“…The mean age was highest in the study by Schreglmann et al, 32 at 71 ± 8.3 years, and lowest in that of Kim et al, 19 at 64.7 years. The means of the duration of tremor in patients in various studies ranged from 12.1 years to 32 years.…”

“…One patient had persisting facial paresis at 12 months. 19 Thus, there was a significant reduction in the number of persisting complications at the end of 12 months after treatment with MRgFUS for ET (Fig. 3E and F).…”

“…The highest improvement in the tremor score was in the study by Chang et al, at 80.43%. 4 The study by Kim et al 19 did not report the actual CRST Total scores, but reported the percentage of patients who had improvement in the ET. This study was not included in the statistical analysis for CRST Total scores.…”

Effects on cognition and quality of life with unilateral magnetic resonance–guided focused ultrasound thalamotomy for essential tremor

“…14,18,24,29,38 Huss et al demonstrated no difference in the change in reported QOL between bilateral Vim DBS and unilateral procedures, including DBS and MRgFUS thalamotomy. 22 A randomized controlled study of MRgFUS thalamotomy described significant reductions of 46% in QUEST scores from baseline to 3 months after ablation as compared with a 3% reduction in the sham group.…”