Focused Ultrasound for Essential Tremor: Review of the Evidence and Discussion of Current Hurdles

BACKGROUND: While there is no breakthrough progress in the medical treatment of essential tremor (ET), in the past decades several remarkable achievements happened in the surgical field, such as radiofrequency thalamotomy, thalamic deep brain stimulation, and gamma knife thalamotomy. The most recent advance in this area is magnetic resonance-guided focused ultrasound (MRgFUS). METHODS: The purpose of this review is to discuss the new developments and trials of MRgFUS in the treatment of ET and other tremor disorders. RESULTS: MRgFUS is an incisionless surgery performed without anesthesia and ionizing radiation (no risk of cumulative dose and delayed side effects). Studies have shown the safety and effectiveness of unilateral MRgFUS-thalamotomy in the treatment of ET. It has been successfully used in a few patients with Parkinson’s disease-related tremor, and in fewer patients with fragile X-associated tremor/ataxia syndrome. The safety and long-term effects of the procedure are still unclear, as temporary and permanent adverse events have been reported as well as recurrence of tremor. DISCUSSION: MRgFUS is a promising new surgical approach with a number of unknowns and unsolved issues. It represents a valuable option particularly for patients who refused or could not be candidates for other procedures, deep brain stimulation in particular.