The potential of focused ultrasound to safely and effectively treat areas deep in the brain was recently underscored by a pilot clinical trial that treated 15 medically refractory patients with essential tremor (ET). Launched in 2011 at the University of Virginia (UVA) and funded by the Focused Ultrasound Foundation, the study used an investigational MR-guided focused ultrasound device (the InSightec ExAblate Neuro) to perform a completely noninvasive unilateral thalamotomy. The treatment goal was to improve ET symptoms on one side of the body, particularly in the dominant hand of each patient.
Final one-year data, presented at the 2013 annual meeting of the American Association of Neurological Surgeons by neurosurgeon William Jeffrey Elias, MD, FAANS, showed a 67 percent improvement in contralateral tremor scores and substantial improvements in daily disabilities (83 percent) and quality of life as assessed by clinicians and patients. Outcomes and complications were comparable to other procedures for tremor, including stereotactic and radiofrequency thalamotomy and deep brain stimulation. Publication of study data is pending.
“We were extremely surprised by the amount of interest the tremor community had in this clinical trial. We have been contacted by more than 2,000 people with tremor, which I think reflects their desire for more treatment options than we currently offer.” – William Jeffrey Elias, MD
Technology overview
With the high cost and morbidity of current techniques, as well as limitations in efficacy of some approaches, the medical needs of many neurological disorders remain unmet. Focused ultrasound is a promising noninvasive platform technology. It has the potential to revolutionize treatment by accessing areas deep within the brain without harming healthy tissue, by ablating targeted tissue without exposing the brain to the effects of ionizing radiation, and by enabling the reversible opening of the blood-brain barrier to deliver therapeutic agents to diseased areas. More than 400 technical, pre-clinical and clinical scientific papers have been published about the application of focused ultrasound to the brain.
Focused ultrasound aims multiple intersecting beams of acoustic energy that can be applied to create a thermal lesion, liquefy blood clots, or activate microbubbles to disrupt the blood-brain barrier. MR-guided focused ultrasound treatment is controlled and monitored through magnetic resonance (MR) imaging. This enables advanced imaging and real-time measurement of bio-effects.
Currently approved for the treatment of uterine fibroids and pain from bone metastases in many regions of the world, MR-guided focused ultrasound applications are being explored for a range of functional, oncologic, neurovascular and psychiatric conditions.
“It is important to realize from these results and those of other tremor procedures that tremor suppression in the dominant hand, even if it is 75 percent on a rating scale, translates to very significant improvement in functional abilities.” – William Jeffrey Elias, MD
Focused Ultrasound Foundation overview
Because it considers the brain to be the vanguard application for focused ultrasound, the Focused Ultrasound Foundation is funding clinical studies to advance highly promising neurological applications of the technology. In addition to the groundbreaking essential tremor pilot study at UVA, the Foundation has also been supporting Phase 1 clinical trials for essential tremor (Sunnybrook Health Sciences Centre) and Parkinsonian tremor (UVA). Foundation-funded clinical trials for brain tumors, Parkinson’s dyskinesia and epilepsy are pending.
Based in Charlottesville, Virginia, the Foundation was created to improve the lives of millions of people worldwide by accelerating the development and adoption of focused ultrasound therapies. To clear the path to global adoption of these therapies, the Foundation coordinates and funds research and educational activities, creates partnerships and fosters collaboration among stakeholders, and builds awareness of “medicine’s best kept secret.”
The Foundation is dedicated to ensuring that focused ultrasound finds its place as a standard of care for cancer, brain tumors, Parkinson’s disease, epilepsy, stroke and other life-threatening conditions within years, not decades. Since its establishment in 2006, the Foundation has become the largest non-governmental source of funding for focused ultrasound research. Complete information about the Foundation and its work can be found online at www.fusfoundation.org.