The New England Journal of Medicine just published a study evaluating InSightec‘s Exablate Neuro focused ultrasound system for treatment of essential tremor. The system received FDA approval to market the device only last month and the study results make clear why. Essentially, transcranial focused ultrasound thalamotomy was effective in reducing hand tremor at three and stayed reduced compared to a control group a year following treatment.
There were side effects, such as unusual sensations felt by 38% of patients that stayed with 14% a year after therapy was administered. About the same numbers apply to people who experienced gait disturbances. This is not unexpected since even though there’s no traditional incision, lesions are created where the ultrasound energy is delivered and concentrated.
All this is very positive not just for patients with essential tremor, but also the future benefits that these findings herald for focused ultrasound in other applications.
Here are the basic findings from the study abstract:
Seventy-six patients were included in the analysis. Hand-tremor scores improved more after focused ultrasound thalamotomy (from 18.1 points at baseline to 9.6 at 3 months) than after the sham procedure (from 16.0 to 15.8 points); the between-group difference in the mean change was 8.3 points (95% confidence interval [CI], 5.9 to 10.7; P<0.001). The improvement in the thalamotomy group was maintained at 12 months (change from baseline, 7.2 points; 95% CI, 6.1 to 8.3). Secondary outcome measures assessing disability and quality of life also improved with active treatment (the blinded thalamotomy cohort)as compared with the sham procedure (P<0.001 for both comparisons). Adverse events in the thalamotomy group included gait disturbance in 36% of patients and paresthesias or numbness in 38%; these adverse events persisted at 12 months in 9% and 14% of patients, respectively.
Here’s an InSightec video explaining the Exablate Neuro: