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Adoption of focused ultrasound thalamotomy for essential tremor: why so much fuss about FUS?
  1. Christian Iorio-Morin1,
  2. Mojgan Hodaie2,
  3. Andres M Lozano2
  1. 1Neurosurgery, Faculté de médecine et des sciences de la santé, Université de Sherbrooke, Sherbrooke, Québec, Canada
  2. 2Division of Neurosurgery, Toronto Western Hospital, Toronto, Ontario, Canada
  1. Correspondence to Dr Christian Iorio-Morin, Neurosurgery, Universite de Sherbrooke Faculte de medecine et des sciences de la sante, Sherbrooke, Quebec, Canada; christian.iorio-morin{at}


Background Focused ultrasound (FUS) was approved as a new treatment modality for essential tremor (ET) in 2016. The goal of this study was to quantify FUS adoption for ET and understand its drivers.

Methods The adoption of the various surgical options for ET was estimated using three measures: the number of presentations on the various surgical treatments for ET at specialised international meetings, the number of original papers published as identified by literature searches and the number of thalamotomy procedures performed worldwide for ET as provided by device manufacturers’ registries.

Results First, we found that the number of presentations related to lesioning procedures is increasing relative to deep brain stimulation (DBS) at international meetings. Second, there are already more publications on FUS (93) than stereotactic radiosurgery (SRS) (68) or radiofrequency (43) for ET, although they still lag behind DBS papers (750). Third, the number of annual FUS thalamotomies performed for ET (n>1200 in 2019) in 44 centres has surpassed the annual procedures across 342 Gamma Knife units (n<400, 2018) but is yet to reach the number of DBS cases for ET estimated at over 2400/year.

Conclusion FUS is being rapidly adopted for the treatment of ET. We hypothesise that its perceived minimally invasive nature coupled with the ability to perform intraoperative clinical assessments, its immediate effects and active marketing efforts are contributing factors. As lesioning modalities for the treatment of ET are reappraised, the superior popularity of FUS over SRS appears to arise for reasons other than differences in clinical outcomes.

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  • Contributors CI-M designed the study, performed the data collection and statistical analysis, and wrote the first draft of the manuscript. MH critically reviewed the manuscript. AML designed the study and critically reviewed the manuscript.

  • Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

  • Competing interests CI-M is founder and CEO of Hyperexis and Abaxial Médical, which are both unrelated to the current study. MH is the Surgical Codirector of the Toronto Western Hospital, Joey & Toby Tanenbaum Family Gamma Knife Centre. AML is the Director of the Toronto Western Hospital Focused Ultrasound Program, Scientific Director for Functional Neuromodulation and consultant for Medtronic, Abbott, Boston Scientific and Insightec.

  • Patient consent for publication Not required.

  • Ethics approval This study did not involve patient data and did not require ethics approval.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available upon reasonable request.

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