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MRI-guided transcranial focused ultrasound (ExAblate Neuro)

Indications: - medication-refractory Parkinson's disease* [1,5] - essential tremor* [1] - Alzheimer's disease (low-intensity focused ultrasound) [2,3] * high-intensity focused ultrasound * improvement in 37/39 patients with duration of benefit > 1 year [1] Contraindications: - contraindicated for patients who cannot have MRI imaging, including those with implanted metallic devices such as cardiac pacemaker - contraindications to gadolinium - body size limitations for MRI - pregnancy - renal failure those - unstable heart conditions - severe hypertension - substance abuse - bleeding disorder - coagulopathy - history of cerebrovascular disease (stroke) - history of brain tumor Procedure: - transcranial image (brain MRI)-guided focuses ultrasound - unilateral pallidotomy [5] for treatment-resistant Parkinson's disease [5] - helmet transducer - patients wear a helmet that has ultrasound probes - 1,000 separate ultrasound transducers angled in different orientations [2] - low-intensity focused ultrasound - MRI is used to visualize areas of the brain with amyloid plaques. - ultrasound waves travel through the scalp & skull converging on the locations in the brain targeted with MRI with a high degree of plaques - tiny spherical microbubbles injected into the bloodstream oscillate in areas targeted with ultrasound, resulting in a transient opening of the blood-brain barrier - treatment takes ~2 hours - patients undergo 3 treatments, each 2 weeks apart. Mechanism of action: - transcranial focused ultrasound can open blood brain barrier - MRI-guided low-intensity focused ultrasound with injected microbubbles to temporarily open the blood-brain barrier reduces beta-amyloid plaques & cognitive impairment in patients with mild Alzheimer's disease [3] - ability to transiently open the blood-brain barrier on demand safely facilitates new therapeutic strategies for treating brain disease

General

ultrasound (US, UTZ)

References

  1. Susman E Focused Ultrasound Ablates Tremor Durable clinical improvement with non-invasive treatment in small study. MedPage Today. Dec 3, 2019 https://www.medpagetoday.com/meetingcoverage/rsna/83663 - Bruno F et al Efficacy of tc-MRgFUS Thalamotomy in The Treatment of Essential Tremor and Parkinson Disease Tremor: Experience From 39 Patients in A Single Centre with Long Term Follow-Up. Radiological Society of North America RSNA 2019; Abstract NR438-SD-WEB7
  2. Susman E Ultrasound Can Open Blood-Brain Barrier. Treatment could improve drug penetration and toxin removal in Alzheimer's patients. MedPage Today. Dec 5, 2019 https://www.medpagetoday.com/meetingcoverage/rsna/83712 - Mehta R, et al Blood-Brain Barrier in the Hippocampus and Entorhinal Cortex Using MR-Guided Focused Ultrasound in Patients with Alzheimer's Disease Radiological Society of North America RSNA 2019; Abstract SSG11-06
  3. Anderson P Low-Intensity Focused Ultrasound Safe, Effective in Mild Alzheimer's Disease. Medscape. August 30, 2021 https://www.medscape.com/viewarticle/957487
  4. FDA News Release. July 11, 2016 FDA approves first MRI-guided focused ultrasound device to treat essential tremor. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm510595.htm
  5. George J Focused Ultrasound Approved for Advanced Parkinson's. Expanded indication includes medication-refractory PD patients with motor problems. MedPage Today November 5, 2021 https://www.medpagetoday.com/neurology/parkinsonsdisease/95458