About the Discussion

@NEJM Ask the Authors & Experts: A Randomized Trial of Focused Ultrasound Thalamotomy for Essential Tremor

Original Article

A Randomized Trial of Focused Ultrasound Thalamotomy for Essential Tremor

W. Jeffrey Elias, M.D.1, Nir Lipsman, M.D., Ph.D.2, William G. Ondo, M.D.3, Pejman Ghanouni, M.D., Ph.D.4, Young Goo Kim, M.D., Ph.D.5, Wonhee Lee, M.D., Ph.D.5, Michael Schwartz, M.D., M.Sc.6, Kullervo Hynynen, Ph.D.6, Andres M. Lozano, M.D.2, Binit B. Shah, M.D.1, Diane Huss, D.P.T., N.C.S.1, Robert F. Dallapiazza, M.D., Ph.D.1, Ryder Gwinn, M.D.7, Jennifer Witt, M.D.7, Susie Ro, M.D. 7, Howard M. Eisenberg, M.D., Ph.D.8, Paul S. Fishman, M.D., Ph.D.8, Dheeraj Gandhi, M.D., M.B., B.S.8, Casey H. Halpern, M.D.4, Rosalind Chuang, M.D.7, Kim Butts Pauly, Ph.D.4, Travis S. Tierney, M.D., Ph.D.9, Michael T. Hayes, M.D.10, G. Rees Cosgrove, M.D.10, Toshio Yamaguchi, M.D., Ph.D.11, Keiichi Abe, M.D.11, Takaomi Taira, M.D., Ph.D.11, and Jin Woo Chang, M.D., Ph.D.5

1University of Virginia Health Sciences Center, Charlottesville, Virginia 2Toronto Western Hospital, Toronto, Canada 3Methodist Neurological Institute, Houston, Texas 4Stanford University School of Medicine, Stanford, California 5Yonsei University College of Medicine, Seoul, Korea 6Sunnybrook Health Sciences Center, Toronto, Canada 7Swedish Neuroscience Institute, Seattle, Washington 8University of Maryland School of Medicine, Baltimore, Maryland 9University of Miami School of Medicine, Nicklaus Children’s Hospital, Miami, Florida 10Brigham and Women’s Hospital, Boston, Massachusetts 11Tokyo Women’s Medical University, Tokyo, Japan

 

BACKGROUND
Uncontrolled pilot studies have suggested efficacy of focused ultrasound thalamotomy for essential tremor.

METHODS
Patients with moderate to severe essential tremor and who had not responded to at least 2 trials of medical therapy were randomized 3:1 to receive a unilateral focused ultrasound thalamotomy or a sham procedure. The Clinical Rating Scale for Tremor and Quality of Life in Essential Tremor questionnaire were obtained at baseline, 1, 3, 6, and 12 months. Tremor assessments were videotaped and rated by an independent group of neurologists who were masked with respect to treatment assignment. The primary outcome was the difference between randomized groups in change from baseline to 3 months in upper limb tremor rated on a 32 point scale (higher scores indicate more severe tremor). After 3 months patients in the sham arm could cross over to active treatment. 

RESULTS
Seventy-six patients were included in the analysis. Upper limb tremor scores improved more after focused ultrasound thalamotomy (18.1 points at baseline to 9.6 at 3 months]) than after sham procedures (from 16.0 to 15.8); the difference between mean changes was 8.3 points (95% CI 5.9-10.7), P<0.001. The improvement in the thalamotomy group was maintained at 12 months (7.2 points (CI 6.1 – 8.3) change from baseline). Secondary outcome measures assessing disability and quality of life also improved as compared with control (P<0.001). Adverse events included gait disturbance in 36% of patients and paresthesias or numbness in 38%; these adverse events persisted at 12 months in 9% and 14%, respectively.

CONCLUSIONS
MRI-guided focused ultrasound thalamotomy improved upper limb tremor in patients with essential tremor. Side effects included sensory and gait disturbances. (ClinicalTrials.gov number, NCT01827904).

 Originally Appeared in The New England Journal of Medicine on August 24, 2016.

Click here to read the original article.