Efficacy and Safety of Magnetic Resonance-Guided Focused Ultrasound Thalamotomy in Essential Tremor: A Systematic Review and Metanalysis

Background: Magnetic resonance-guided focused ultrasound (MRgFUS) is an established surgical treatment for essential tremor, providing tremor relief without the need for an incision or general anesthesia. Meta-analyses have been limited in their exploration of the durability of the treatment effect. Objectives: The study aimed to assess the treatment effect and safety of this procedure over time. Different to other meta-analyses, this study assessed the durability of efficacy over time from 1 month to 5 years follow-up. Investigating the recurrence of tremor was an important target of this work. Methods: A systematic search of the literature utilizing set search criteria was conducted with the PubMed, Scopus, Web of Science, and Cochrane library databases, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Data analysis was conducted in R, utilizing a random-effects model for meta-analysis and a mixed-effects model for meta-regression. Results: Forty-five studies met the inclusion criteria, of which 42 were included in the analyses. Significant changes in hand tremor, total tremor, disability scores, and quality of life scores were demonstrated across the time points investigated, the pooled standardized mean differences being −2.36 (P < 0.0001), −2.08 (P < 0.0001), −2.85 (P < 0.0001), and −1.41 (P < 0.0001) 1 year post-operation. Sensory symptoms and unsteadiness adverse events were frequently observed, with pooled proportions of 22% (95% CI 15%; 31%) and 23% (95% CI 16%; 31%) 1 month post-MRgFUS. Conclusion: Although the procedure demonstrated efficacy and safety across the studies evaluated, meta-regression analysis suggests a decrease in treatment effect over time that requires further investigation.