University of Maryland School of Medicine (UM SOM) researchers, along with an international group of investigators, have discovered for the first time that treatment with MRI-guided focused ultrasound can effectively treat patients with essential tremor (ET), a neurological movement disorder that affects an estimated 10 million people in the U.S. The results, which are published in the forthcoming issue of the New England Journal of Medicine, led to recent approval of the treatment by the Food & Drug Administration (FDA).
ET, unlike Parkinson’s disease, has been viewed as a relatively benign disease caused by abnormalities in the brain. However, its disabling aspects – sometimes severe involuntary and rhythmic shaking in the hands and other extremities – can impair an individual’s ability to perform the simplest tasks, such as eating or holding a pen. Currently, ET affects an estimated 3 percent of Americans, and up to the present, has been treated by medication, surgical procedures or deep brain stimulation (DBS).
The randomized, double-blinded study showed that 56 patients who received the treatment experienced a nearly 50 percent improvement in their tremors and motor function after three months and retained a 40 percent improvement after a year. In contrast, 20 patients who received a sham treatment saw no improvement and were able to cross over into the treatment group three months later.
“We are very excited to have this new noninvasive treatment option for patients who struggle every day with this debilitating neurological disorder,” says study co-author Howard M. Eisenberg, MD, the RK Thompson Professor and Chair of Neurosurgery at the UM SOM. “We saw an impressive reduction in tremors in hands and arms and an improvement in quality of life in patients who experienced no relief from medication.”
Twenty-seven of the patients in the year-long study were treated at the University of Maryland Medical Center (UMMC), with many who received the new therapy achieving up to a 99 percent improvement in their tremors.
Paul Fishman, MD, Professor of Neurology, Pharmacology and Neurobiology at UM SOM and Chief of Neurology for the Maryland VA Health Care System, and Dheeraj Gandhi, M.D., MBBS, Professor of Radiology, Neurosurgery and Neurology and Director of Interventional Neuroradiology at UM SOM, are also co-authors of the study. W. Jeffrey Elias, MD, Director of Stereotactic and Functional Neurosurgery at the University of Virginia, is the principal investigator and lead author.
There were eight sites for the clinical trial, five of them in the United States.
In the study, researchers looked at 76 patients who had essential tremor but had not responded to medication. They used magnetic resonance imaging (MRI) to guide ultrasound waves with a millimeter-wide focus through the intact skin and skulls of the study participants, in order to make precise ablations (surgical removal of tissue) in the thalamus, an area deep within the brain thought to play a key role in ET.
“You are raising the temperature in a very restricted area of the brain and that destroys the tissue,” says Dr. Eisenberg. “The ultrasound creates a heat lesion that you monitor through MRI.”
The entire procedure lasts two to four hours, and patients are awake and able to interact with the treatment team. Researchers ask patients to draw spirals on a piece of paper, which are then compared with drawings done before the treatment to determine its effectiveness in calming the tremor.
The study was funded by the Focused Ultrasound Foundation, BIRD Foundation and Insightec, the equipment’s manufacturer. Dr. Eisenberg is a consultant to both the Focused Ultrasound Foundation and Insightec.
“University of Maryland School of Medicine faculty physicians have been leaders in exploring the potential of MRI-guided focused ultrasound to treat essential tremor as well as Parkinson’s disease, two movement disorders that affect millions in the U.S. and around the world,” says UM SOM Dean E. Albert Reece, MD, PhD, MBA, who is also Vice President of Medical Affairs at the University of Maryland and the John Z. and Akiko Bowers Distinguished Professor at UM SOM.
“This groundbreaking study clearly demonstrates that focused ultrasound can be transmitted with precision through the human skull to target areas deep with the brain – and improve the quality of life of patients with essential tremor who have difficulty performing tasks that most of us take for granted,” Dr. Reece says.”
About the University of Maryland School of Medicine
The University of Maryland School of Medicine was chartered in 1807 and is the first public medical school in the United States. It continues today as an innovative leader in accelerating innovation and discovery in medicine. The School of Medicine is the founding school of the University of Maryland and is an integral part of the 11-campus University System of Maryland. Located on the University of Maryland’s Baltimore campus, the School of Medicine works closely with the University of Maryland Medical Center and Medical System to provide a research-intensive, academic and clinically based education. With 43 academic departments, centers and institutes and a faculty of more than 3,000 physicians and research scientists plus more than $400 million in extramural funding, the School is regarded as one of the leading biomedical research institutions in the U.S. with top-tier faculty and programs in cancer, brain science, surgery and transplantation, trauma and emergency medicine, vaccine development and human genomics, among other centers of excellence. The School is not only concerned with the health of the citizens of Maryland and the nation, but also has a global presence, with research and treatment facilities in more than 35 countries around the world. medschool.umaryland.edu/
About the University of Maryland Medical Center
The University of Maryland Medical Center (UMMC) is comprised of two hospitals in Baltimore: an 800-bed teaching hospital — the flagship institution of the 12-hospital University of Maryland Medical System (UMMS) — and a 200-bed community teaching hospital, UMMC Midtown Campus. UMMC is a national and regional referral center for trauma, cancer care, neurocare, cardiac care, diabetes and endocrinology, women’s and children’s health and has one of the largest solid organ transplant programs in the country. All physicians on staff at the flagship hospital are faculty physicians of the University of Maryland School of Medicine. At UMMC Midtown Campus, faculty physicians work alongside community physicians to provide patients with the highest quality care. UMMC Midtown Campus was founded in 1881 and is located one mile away from the University Campus hospital. For more information, visit www.umm.edu