Focused ultrasound treatment for essential tremor has been approved by the Food and Drug Administration (FDA) in July 2016. Medicare approved the treatment in all US states as of July 12, 2020.
Essential tremor (ET) is the most common movement disorder, affecting an estimated 3% of the population, or approximately 10 million individuals in the United States. ET is commonly viewed as a relatively benign disease.
However, the associated disabling aspects of ET, such as significant tremor of the hands, can impair patients’ ability to eat, shave, write, perform household activities, and function in the workplace.
The underlying etiology of ET is unclear, but cases often run in families (familial tremor). It has been estimated that approximately 50% of all cases are due to a genetic mutation, and the pattern of inheritance is most consistent with autosomal dominant transmission (i.e. dominant trait).
Focused Ultrasound Therapy
Focused ultrasound is a noninvasive, therapeutic technology with the potential to improve the quality of life and decrease the cost of care for patients with essential tremor. This novel technology focuses multiple beams of ultrasound energy precisely and accurately on targets deep in the brain without damaging surrounding normal tissue.
How it Works
Where the focused ultrasound beams converge, they produce precise ablation (thermal destruction of tissue), enabling ET to be treated noninvasively. The primary target is a region in the thalamus called the ventral intermediate nucleus (Vim), but other adjacent targets and white matter pathways are also in use.
Current treatments are being performed on one side of the brain, but there is a study underway of staged bilateral treatments.
- It is a noninvasive, single treatment that enables patients to recover rapidly and quickly return to activities of normal life (usually the next day).
- Compared to RF ablation or DBS, focused ultrasound offers a reduced risk of infection, of damage to the non-targeted area, and of blood clot formation.
- Focused ultrasound offers rapid resolution of symptoms.
- In contrast to lesioning performed with stereotactic radiosurgery, focused ultrasound does not use ionizing radiation, thus avoiding the side effects of exposure to radiation.
- Because it is non-invasive, focused ultrasound could be an option for medically refractory ET patients (those who do not respond well to medication) who do not want to undergo surgery.
Phase 3 Pivotal Clinical Study
Enrollment has been completed in a multi-center pivotal randomized study to evaluate the safety and efficacy of focused ultrasound for the treatment of medication-refractory essential tremor patients. Results of this study are intended to be reviewed and hopefully approved by the FDA.
A multi-site US clinical trial investigating staged bilateral treatments for ET has been extended to treat a total of 50 patients. The interval between treatments is at least nine months.
A clinical trial in the UK and Spain has begun and is doing staged bilateral treatments. This group will treat the second side after at least nine months have passed after the first treatment.
Please see a list of possible treatment sites here.
Regulatory & Reimbursement
The Exablate system manufactured by Insightec earned FDA approval to treat essential tremor in July 2016. It is also approved for treating essential tremor in Europe, Korea, Canada, Japan, Russia, Taiwan, and the Middle East.
In the US, the Medicare contractors in the various states incrementally approved focused ultrasound treatment for essential tremor. However, on July 12, 2020, all US sites have been approved for payment under Medicare.
Commercial coverage and Medicaid will typically follow Medicare but should be evaluated with each company and region. Some facilities have a cash payment option, for those who are not willing to wait for insurance decisions for payment. Prices vary, but a rough estimate is $40,000.
Device manufacturer, Insightec has established an informational website, including patient stories and access to treatment site information. They have also set up a Reimbursement Support Manager, who can help with questions about the status of reimbursements. Her contact information is: Kim Martin, Reimbursement Support Manager, 1-(866) 392-8478 or .
De Vloo P, Boutet A, Elias GJB, Gramer RM, Joel SE, Llinas M, Kucharczyk W, Fasano A, Hamani C, Lozano AM. Dysgeusia induced and resolved by focused ultrasound thalamotomy: case report. J Neurosurg. 2021 Jun 18:1-6. doi: 10.3171/2020.11.JNS202882.
Agrawal M, Garg K, Samala R, Rajan R, Naik V, Singh M. Outcome and Complications of MR Guided Focused Ultrasound for Essential Tremor: A Systematic Review and Meta-Analysis. Front Neurol. 2021 May 7;12:654711. doi: 10.3389/fneur.2021.654711. eCollection 2021.
Kim MJ, Park SH, Chang KW, Kim Y, Gao J, Kovalevsky M, Rachmilevitch I, Zadicario E, Chang WS, Jung HH, Chang JW. Technical and operative factors affecting magnetic resonance imaging-guided focused ultrasound thalamotomy for essential tremor: experience from 250 treatments. J Neurosurg. 2021 May 21:1-9. doi: 10.3171/2020.11.JNS202580.
Miller WK, Becker KN, Caras AJ, Mansour TR, Mays MT, Rashid M, Schwalb J. Magnetic resonance-guided focused ultrasound treatment for essential tremor shows sustained efficacy: a meta-analysis.** Neurosurg Rev. 2021 May 12. doi: 10.1007/s10143-021-01562-w.
Jameel A, Bain P, Nandi D, Jones B, Gedroyc W. Device profile of exAblate Neuro 4000, the leading system for brain magnetic resonance guided focused ultrasound technology: an overview of its safety and efficacy in the treatment of medically refractory essential tremor. Expert Rev Med Devices. 2021 May 13:1-9. doi: 10.1080/17434440.2021.1921572.
Varma-Doyle AV, Villemarette-Pittman NR, Copeland BJ. Hemi-parkinsonism and return of essential tremors after MRgFUS thalamotomy: Case report and review of procedural complications affecting ventral thalamic nuclei. eNeurologicalSci. 2021 Apr 13;23:100339. doi: 10.1016/j.ensci.2021.100339. eCollection 2021 Jun.
Martínez-Fernández R, Mahendran S, Pineda-Pardo JA, Imbach LL, Máñez-Miró JU, Büchele F, Del Álamo M, Rodriguez-Rojas R, Hernández-Fernández F, Werner B, Matarazzo M, Obeso I, Gonzalez-Quarante LH, Deuschl G, Stieglitz L, Baumann CR, Obeso JA. Bilateral staged magnetic resonance-guided focused ultrasound thalamotomy for the treatment of essential tremor: a case series study. J Neurol Neurosurg Psychiatry. 2021 Apr 27:jnnp-2020-325278. doi: 10.1136/jnnp-2020-325278.
Iorio-Morin C, Hodaie M, Lozano AM. Adoption of focused ultrasound thalamotomy for essential tremor: why so much fuss about FUS? J Neurol Neurosurg Psychiatry. 2021 Feb 9:jnnp-2020-324061. doi: 10.1136/jnnp-2020-324061.
Chang KW, Rachmilevitch I, Chang WS, Jung HH, Zadicario E, Prus O, Chang JW. Safety and Efficacy of Magnetic Resonance-Guided Focused Ultrasound Surgery With Autofocusing Echo Imaging. Front Neurosci. 2021 Jan 12;14:592763. doi: 10.3389/fnins.2020.592763. eCollection 2020.
Abe K, Horisawa S, Yamaguchi T, Hori H, Yamada K, Kondo K, Furukawa H, Kamada H, Kishima H, Oshino S, Mochizuki H, Kanemoto M, Hirabayashi H, Fukutome K, Ohnishi H, Igase K, Matsubara I, Ohnishi T, Sadamoto K, Taira T. Focused Ultrasound Thalamotomy for Refractory Essential Tremor: A Japanese Multicenter Single-Arm Study. Neurosurgery. 2021 Jan 19:nyaa536. doi: 10.1093/neuros/nyaa536.
Osterholt T, McGurrin P, Bedard P, Horovitz S, Ehrlich D, Haubenberger D. Thalamic Tremor Following Focused Ultrasound Thalamotomy for the Treatment of Essential Tremor. Mov Disord Clin Pract. 2020 Oct 27;8(1):139-141. doi: 10.1002/mdc3.13097. eCollection 2021 Jan.
Giordano M, Caccavella VM, Zaed I, Foglia Manzillo L, Montano N, Olivi A, Polli FM. Comparison between deep brain stimulation and magnetic resonance-guided focused ultrasound in the treatment of essential tremor: a systematic review and pooled analysis of functional outcomes. J Neurol Neurosurg Psychiatry. 2020 Dec;91(12):1270-1278. doi: 10.1136/jnnp-2020-323216. Epub 2020 Oct 14.
De Vloo P, Milosevic L, Gramer RM, Dallapiazza RF, Lee DJ, Fasano A, Hutchison WD, Lozano AM, Schwartz ML, Kalia SK. Microelectrode Recording and Radiofrequency Thalamotomy following Focused Ultrasound Thalamotomy. Stereotact Funct Neurosurg. 2020 Sep 16:1-4. doi: 10.1159/000510109.
McDannold NJ, White PJ, Cosgrove GR. MRI-based thermal dosimetry based on single-slice imaging during focused ultrasound thalamotomy. Phys Med Biol. 2020 Sep 11. doi: 10.1088/1361-6560/abb7c4.
Jones RM, Huang Y, Meng Y, Scantlebury N, Schwartz ML, Lipsman N, Hynynen K. Echo-Focusing in Transcranial Focused Ultrasound Thalamotomy for Essential Tremor: A Feasibility Study. Mov Disord. 2020 Aug 20. doi: 10.1002/mds.28226.
Su JH, Choi EY, Tourdias T, Saranathan M, Halpern CH, Henderson JM, Pauly KB, Ghanouni P, Rutt BK. Improved Vim targeting for focused ultrasound ablation treatment of essential tremor: A probabilistic and patient-specific approach. Hum Brain Mapp. 2020 Aug 6. doi: 10.1002/hbm.25157.
Saluja S, Barbosa DAN, Parker JJ, Huang Y, Jensen MR, Ngo V, Santini VE, Pauly KB, Ghanouni P, McNab JA, Halpern CH. Case Report on Deep Brain Stimulation Rescue After Suboptimal MR-Guided Focused Ultrasound Thalamotomy for Essential Tremor: A Tractography-Based Investigation. Front Hum Neurosci. 2020 Jun 26;14:191. doi: 10.3389/fnhum.2020.00191. eCollection 2020.
Kapadia AN, Elias GJB, Boutet A, Germann J, Pancholi A, Chu P, Zhong J, Fasano A, Munhoz R, Chow C, Kucharczyk W, Schwartz ML, Hodaie M, Lozano AM. Multimodal MRI for MRgFUS in essential tremor: post-treatment radiological markers of clinical outcome. J Neurol Neurosurg Psychiatry. 2020 Jul 10:jnnp-2020-322745. doi: 10.1136/jnnp-2020-322745.
Ito H, Yamamoto K, Fukutake S, Odo T, Kamei T. Two-year Follow-up Results of Magnetic Resonance Imaging-guided Focused Ultrasound Unilateral Thalamotomy for Medication-refractory Essential Tremor. Intern Med. 2020 Jul 7. doi: 10.2169/internalmedicine.4360-19.
Yamamoto K, Ito H, Fukutake S, Odo T, Kamei T, Yamaguchi T, Taira T. Movement during focused ultrasound therapy caused by an unstable magnetic resonance table: case report. J Neurosurg. 2020 Jul 3:1-4. doi: 10.3171/2020.4.JNS20219.
Buch VP, McShane BJ, Beatson N, Yang A, Blanke A, Tilden D, Korn M, Chaibainou H, Ramayya A, Wombacher K, Maier S, Marashlian T, Wolf R, Baltuch GH. Focused Ultrasound Thalamotomy with Dentato-Rubro-Thalamic Tractography in Patients with Spinal Cord Stimulators and Cardiac Pacemakers. Stereotact Funct Neurosurg. 2020 May 13:1-7. doi: 10.1159/000507031.
Fukutome K, Kuga Y, Ohnishi H, Hirabayashi H, Nakase H. What factors impact the clinical outcome of magnetic resonance imaging guided focused ultrasound thalamotomy for essential tremor? J Neurosurg. 2020 May 1:1-6. doi: 10.3171/2020.2.JNS192814.
Chapman M, Park A, Schwartz M, Tarshis J. Anesthesia considerations of magnetic resonance imaging-guided focused ultrasound thalamotomy for essential tremor: a case series. Can J Anaesth. 2020 Apr 14. doi: 10.1007/s12630-020-01644-1.
Bruno F, Catalucci A, Arrigoni F, Sucapane P, Cerone D, Cerrone P, Ricci A, Marini C, Masciocchi C. An experience-based review of HIFU in functional interventional neuroradiology: transcranial MRgFUS thalamotomy for treatment of tremor. Radiol Med. 2020 Apr 7. doi: 10.1007/s11547-020-01186-y.
Paff M, Boutet A, Neudorfer C, Elias GJB, Germann J, Loh A, Kucharczyk W, Fasano A, Schwartz ML, Lozano AM. Magnetic Resonance-Guided Focused Ultrasound Thalamotomy to Treat Essential Tremor in Nonagenarians. Stereotact Funct Neurosurg. 2020 Mar 30:1-5. doi: 10.1159/000506817.
Gallay MN, Moser D, Jeanmonod D. MR-guided focused ultrasound cerebellothalamic tractotomy for chronic therapy-resistant essential tremor: anatomical target reappraisal and clinical results. J Neurosurg. 2020 Feb 7:1-10. doi: 10.3171/2019.12.JNS192219.
Parras O, Domínguez P, Tomás-Biosca A, Guridi J. The role of tractography in the localization of the Vim nucleus of the thalamus and the dentato-rubro-thalamic tract for the treatment of tremor. Neurologia. 2020 Jan 5. pii: S0213-4853(19)30131-8. doi: 10.1016/j.nrl.2019.09.006. [Epub ahead of print] Review. English, Spanish.
Click here for additional references from PubMed.
Pre- and post-treatment assessment videos courtesy of University of Virginia