Focused Ultrasound Therapy
Focused ultrasound is an early-stage, noninvasive, therapeutic technology with the potential to improve the quality of life and decrease the cost of care for patients with dystonia. This novel technology focuses beams of ultrasound energy precisely and accurately on targets deep in the brain without damaging surrounding normal tissue. Where the beams converge, the ultrasound produces precise ablation (thermal destruction of tissue) enabling dystonia to be treated without surgery. While there are several potential treatment targets, the ventrooralis (Vo nucleus of the thalamus) has been the target of initial studies treating musician’s or writer’s dystonia.
The primary options for treatment of dystonia include medications and invasive surgery.
For certain patients, focused ultrasound could provide a noninvasive alternative to surgery with less risk of complications and lower cost.
- Focused ultrasound is noninvasive, so it does not carry added concerns like surgical wound healing or infection.
- The medications work temporarily, where focused ultrasound will work for a much longer period of time, and may be permanent.
- If needed, focused ultrasound can be repeated.
A clinical trial in Japan has been completed, and researchers will be publishing the data soon. The trial is aimed at patients who have writer’s cramp or musician’s dystonia of the hand, and studies the safety and initial efficacy for an ablative unilateral Vo thalamotomy. A preliminary report of one patient has been released.
Another clinical trial at Toronto Western Hospital is based on a variety of causes of movement disorders and includes dystonia in the spectrum of diseases for treatment. The purpose is to examine the safety and initial effectiveness of focused ultrasound for treatment of movement disorders. This study is ONLY open to citizens of Canada.
Regulatory Approval and Reimbursement
Focused ultrasound treatment for dystonia is not yet approved by regulatory bodies or covered by medical insurance companies.
Horisawa S, Yamaguchi T, Abe K, Hori H, Sumi M, Konishi Y, Taira T. A single case of MRI-guided focused ultrasound ventro-oral thalamotomy for musician's dystonia. J Neurosurg. 2018 Sep 21:1-3. doi: 10.3171/2018.5.JNS173125.
Krishna V, Sammartino F, Rezai A. A Review of the Current Therapies, Challenges, and Future Directions of Transcranial Focused Ultrasound Technology: Advances in Diagnosis and Treatment. JAMA Neurol. 2018 Feb 1;75(2):246-254. doi: 10.1001/jamaneurol.2017.3129.
Krack P, Martinez-Fernandez R, Del Alamo M, Obeso JA. Current applications and limitations of surgical treatments for movement disorders. Mov Disord. 2017 Jan;32(1):36-52. doi: 10.1002/mds.26890. Review.
Horisawa S, Taira T, Goto S, Ochiai T, Nakajima T. Long-term improvement of musician’s dystonia after stereotactic ventro-oral thalamotomy. Ann Neurol 2013;74:648-654.
Taira T, Hori T. Stereotactic ventrooralis thalamotomy for task-specific focal hand dystonia (writer’s cramp). Stereotact Funct Neurosurg 2003;80:88–91.
Taira T, Harashima S, Hori T. Neurosurgical treatment for writer’s cramp. Acta Neurochir 2003;[Suppl]87:129-131.
Goto S, Tsuiki H, Soyama N, et al. Stereotactic selective Vo-complex thalamotomy in a patient with dystonic writer’s cramp. Neurology 1997;49:1173–1174.