KEY TAKEAWAYS
Three decades ago, researchers at Brigham and Women’s Hospital pioneered MRI-guided focused ultrasound (MRgFUS) thalamotomy, a technique that offers lifechanging results for patients. In a new study, researchers looked at results from more than 350 patients treated with MRgFUS for essential tremor to assess clinical improvements and side effects. Their research creates a model of an optimal location for ablation, which will help make the procedure safer and more effective for patients at Mass General Brigham and around the world. For millions of people around the world with essential tremor, everyday activities from eating and drinking to dressing and doing basic tasks can become impossible. This common neurological movement disorder causes uncontrollable shaking, most often in the hands, but it can also occur in the arms, legs, head, voice, or torso. Essential tremor impacts an estimated 1 percent of the worldwide population and around 5 percent of people over 60. Investigators from Mass General Brigham identified a specific subregion of the brain’s thalamus that, when included during magnetic resonance-guided focused ultrasound (MRgFUS) treatment, can result in optimal and significant tremor improvements while reducing side effects. Their results are published in Science Advances.
“This one-time, noninvasive treatment can have immediate, long-lasting and lifechanging effects for patients and was pioneered here at Brigham and Women’s Hospital 30 years ago,” said co-senior author G. Rees Cosgrove, MD, FRCSC, director of functional neurosurgery at Brigham and Women’s Hospital, a founding member of the Mass General Brigham healthcare system. “The results of this study will help make the procedure even more safe and effective than it already is and will help other centers around the world improve their outcomes.”
MRgFUS treatment of essential tremor creates a small, permanent lesion in a specific nucleus in the thalamus that is thought to be part of the brain circuit mediating the disorder and disrupts the tremor-causing activity. The research team analyzed data from 351 thalamotomy patients that were treated across three international hospitals, the largest cohort assessed to date, to identify the optimal location for this procedure and better understand its impacts on clinical improvements and side effects.
The study identified a set of optimal sites and brain connections to target, as well as locations and connections to avoid that lead to side effects. The team then tested whether this ‘sweet spot’ could be used as a model to predict the outcomes in a cohort of patients treated with the same procedure at another center, which proved true. The more the ‘sweet spot’ was lesioned, the better the outcome was in all patients’ one-year, post-procedure comparison data. According to the researchers, when thalamotomy patients have good tremor control at one year, it is typically sustained over multiple years.
“Seeing how this procedure can make such a huge impact on patients’ lives is what motivated me to pursue this research,” said lead author Melissa Chua, MD, a senior resident in the Brigham’s Department of Neurosurgery. “It is very exciting to have such robust validation and to be moving toward this treatment becoming even more precise and personalized in the future.”
Next, the team plans to further analyze patient data to present a more detailed picture of the evolution of this technology and how patient outcomes have improved, to fully understand the parameters that go into achieving long-term tremor control and minimized side effects.
“It is incredible when you can provide a patient with relief from these tremors,” Cosgrove said. “It is like a gift when patients who have not been able to sing, speak in public, write, or even drink from a cup for years can once again do so—we see it in case after case.”
Authorship: In addition to Chua and Cosgrove, Mass General Brigham authors include Alfredo Morales Pinzon, Clemens Neudorfer, Patrick R Ng, Sarah E Blitz, Garance M Meyer, Konstantin Butenko, Till A Dembek, Fardad Behzadi, Nathan J McDannold, John D Rolston, Charles RG Guttmann, Michael D Fox, and Andreas Horn. Additional authors include Alexandre Boutet, Andrew Z Yang, Michael Schwartz, Jürgen Germann, Nir Lipsman, and Andres Lozano.
Disclosures: Cosgrove is a consultant for Insightec which manufactures the MRgFUS equipment. Fox has intellectual property on the use of brain connectivity imaging to analyze lesions and guide brain stimulation, and is a consultant for Magnus Medical, Soterix, Abbott, and Boston Scientific. Horn reports lecture fees for Boston Scientific and is a consultant for FxNeuromodulation and Abbott.
Funding: National Institutes of Health (R01MH113929, R21MH126271, R56AG069086, R21NS123813, R01NS127892, R01MH130666, UM1NS132358, R01 13478451, 1R01NS127892-01, 2 R01 MH113929, UM1NS132358) Neuronentics grant, Kaye Family Research Endowment, Ellison / Baszucki Family Foundation, Manley Family, Focused Ultrasound Foundation grant (CRGG), German Research Foundation (Deutsche Forschungsgemeinschaft, 424778381 – TRR842 295), Deutsches Zentrum für Luft- und Raumfahrt (DynaSti grant within the EU Joint Programme Neurodegenerative Disease Research, JPND), New Venture Fund (FFOR Seed Grant).
Paper cited: Chua M et al. “Optimal Focused Ultrasound Lesion Location in Essential Tremor” Science Advances DOI: 10.1126/sciadv.adp0532 For More Information:
Parkinson’s Disease vs. Essential Tremor: What’s the Difference? | Mass General Brigham
Focused Ultrasound: Noninvasive Surgery Stops Tremor in its Tracks
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