Assessment of the safety of MRgFUS-thalamotomy in patients with essential tremor in real-world clinical practice.

In a pivotal randomized clinical trial (RCT) in patients with essential tremor, MRgFUS-thalamotomy produced immediate and significant tremor relief which has been sustained for at least 5 years. The procedure was generally well-tolerated and the most common adverse events (AEs) were transient and mild.

Safety findings from RCTs, in which strict patient-monitoring procedures are adhered to are not representative of everyday clinical practice. We therefore investigated safety findings from real-world sources including registries, the literature, company-reported complaints, and surveys data from commercial customers. These were compared with safety findings from the RCT of MRgFUS-thalamotomy in patients with essential tremor.

In the pivotal RCT, the most common AEs reported within 30 days of treatment were gait disturbance (18%) and paresthesias or numbness (25%). These persisted at 12 months in 9-14% of patients, respectively. After 5-years, all AEs were classified as mild (71%) or moderate (29%) and none were serious. No new AEs related/probably-related to the procedure from the 12-month timepoint to the last follow-up at 5 years were observed. A similar safety profile was observed in a registry study which included 248 patients undergoing MRgFUS-thalamotomy, with no serious AEs recorded to date. Results from the literature were also very similar and included mild transitory procedure-related AEs (e.g., headache, nausea/vomiting, floating sensation) and short-term mild-to-moderate gait disturbances and paresthesias or numbness which diminished over time. AEs were reported in 2.6% of 3700 commercial procedures. Additional data from customer surveys (2018-2020) suggests that safety perception is good/fair to very good/excellent.

Overall, unilateral MRgFUS-thalamotomy in a real-world setting is safe and well-tolerated. This evidence supports the use of MRgFUS-thalamotony in patients with essential tremor in real-world, everyday clinical practice.