Key Points
- Clinical evidence continues to accrue for bilateral focused ultrasound treatment for essential tremor.
- Prof. Andres Lozano, MD, PhD, and a team of researchers have published new clinical trial data in the journal Movement Disorders.
- When asked whether they would treat the second side again, all 10 patients said yes.
Bilateral Focused Ultrasound Thalamotomy for Essential Tremor (BEST-FUS Phase 2 Trial)
Clinical evidence continues to accrue for bilateral focused ultrasound treatment (thalamotomy) for essential tremor (ET). To add to the accumulating data, a collaborative group of researchers based primarily in Canada and led by Prof. Andres Lozano, MD, PhD, published clinical trial data from 10 participants in the November 2021 issue of the journal Movement Disorders.
In this study, change in quality of life (QOL) after three months, relative to baseline, was a primary outcome measure. When asked, “Given what you know now, would you treat the second side again,” all patients reported that they would elect to receive the second-side treatment again. The improvement in QOL at three months was clinically significant, and the tremor was significantly improved in all patients. The trial also tracked tremor, gait, speech, and adverse effects. Seven of the ten participants experienced mild adverse effects.
Patients with ET who currently undergo focused ultrasound thalamotomy must choose one side for tremor relief; therefore, the symptoms remain on the untreated side. Research groups around the world have begun to test the safety and effectiveness of treating first one side and then the other – after time has elapsed.
Prof. Lozano’s group concluded that staged, bilateral focused ultrasound thalamotomy can be performed with the same reasonably safe procedure as unilateral thalamotomy. Although long-term follow-up and validation are still needed, the bilateral procedure appears to improve both tremor and QOL for these patients.
Staged, bilateral ET studies have been, or are being, conducted at additional enrollment sites in Switzerland, the United Kingdom, Germany/Spain/Switzerland, Spain/United Kingdom, Canada, and the United States.