Long-Term Tremor Reduction With Magnetic Resonance-Guided Focused Ultrasound Thalamotomy

ExAblate Neuro
ExAblate Neuro
The investigators excluded non-responders to MRgFUS, which may have produced an overestimate of the therapy's benefit in the remaining patients.

Tremor reduction following magnetic resonance-guided focused ultrasound (MRgFUS) thalamotomy in patients with essential tremor is maintained up to 2 years following treatment, according to study findings published in the Annals of Neurology.

In this open-label extension trial, a total of 67 patients with moderate to severe essential tremor were followed for 2 years after randomization to unilateral thalamotomy. For the 76 patients in the original trial, the mean hand tremor score was 19.8±4.9.

At 6 months, there was a 55% improvement in the mean hand tremor score following MRgFUS thalamotomy (from 19.8±4.9 to 8.6±4.5) among 75 patients. This improvement was maintained at 1-year follow-up in 70 patients (from 19.8±4.9 to 8.9±4.8) and at 2-year follow-up in the 67 patients in the open-label extension trial (from 19.8±4.9 to 8.8±5.0, change in the score from baseline to 2 years, 11 points; 95% CI, 7.6-10.0; P <.001).

Additionally, MRgFUS thalamotomy was associated with a significant 64% improvement in disability from baseline to 6 months in the original 75 patients (16.4±4.5 to 5.4±4.7], P <.001), and this improvement was sustained in the 2-year follow-up cohort (6.5±5.0, change in the score from baseline to 2 years, 9.9 points; 95% CI, 5.3-7.7; P <.001). Investigators observed no new delayed complications at the end of the 2-year follow-up.

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Some of the patients in the original cohort dropped out of the study by 2 years, thereby limiting the sample size. In addition, the investigators excluded nonresponders to MRgFUS, which may have produced an overestimate of the therapy’s benefit in the remaining patients.

The investigators noted that one of the benefits of MRgFUS for essential tremor is its use of neurologic evaluation during treatment, which “allows for modification of the treatment plan to improve efficacy and safety.”


Chang JW, Park CK, Lipsman N, et al. A prospective trial of magnetic resonance guided focused ultrasound thalamotomy for essential tremor: results at the 2-year follow-up [published online December 19, 2017]. Ann Neurol. doi:10.1002/ana.25126