Objective: To describe the safety and efficacy of bilateral focused ultrasound thalamotomy (FUS) in a cohort of patients with essential tremor (ET) within the Spanish public health system.

Background: Staged bilateral FUS thalamotomy demonstrated to be safety and effective in patients with essential tremor in a single-arm, single-blinded phase 2 trial in 2021 and was approved by the European Medicines Agency in September 2023.

Method: Patients with ET who underwent staged bilateral FUS thalamotomy in our center between October 2023 and February 2024 were included. Patients were assessed pre-procedure and at follow-up(FU) visits (7-day, 3-months). Tremor was assessed using the Clinical Rating Scale for tremor (CRST) parts A, B and C, as well as a subscore for the tasks specific to the treated side. Adverse events were collected.

Results: 12 patients were included (all patients had available data for 7-day visit, 1 for 3-months). Mean age was 72±7.53 years; time between the first and the second treatment was 18±5.19 months. After the second thalamotomy, an improvement of 75.65% was observed in the CRST subscore of the treated side (16.8±4.42 preprocedure, 4.09±3.64 at 7-day).   The CRST-A  score  decreased  from  10.58±4.03 to 2.45±1.81.  CRST B and C also decreased from baseline to 7-day (B: 16.67±5.36 preprocedure, 5.27±6.06 at 7-day; C: 15.25±7.14 preprocedure, 2.00±2.05 at 7-day).  Comparing baseline (before any treatment) and after the first and second thalamotomy, we observed a statistically significant improvement in all CRST subscores not only after the first FUS thalamotomy but also after the second one (baseline/FUS1/FUS2): CRST-total 60.50±14.40/23.30±9.21/10.73±6.71; CRST-A: 19.78±8.04/8.7±4.06/2.45±1.81; CRST-B 28.67±6.58/12.70±4.74/7.73±5.18; CRST-C: 26.80±8.53/14.09±4.64/2.0±2.05; p<0.001). None of the patients presented a permanent adverse event after the first treatment. 7/12(58.3%) of the patients had any adverse event during the procedure (33.3% headache, 33.3 % dizziness, 25 % nausea). The most frequent adverse events related to thalamotomy presented at 7-day were: 5(41.7%) gait instability, 5(41.7%) hypoesthesia, 4(33.3%)dysarthria,  1(8.3%)dysmetria and 2(16.7%) dysgeusia.

Conclusion: Bilateral FUS thalamotomy for treatment of disabling tremor in the public health system shows a reasonable safety profile and improves the tremor of patients with ET.

« Back to 2024 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/safety-and-efficacy-of-bilateral-magnetic-resonance-guided-focused-ultrasounds-fus-thalamotomy-for-refractory-essential-tremor/