By Sam Parker
It’s only a start, but preliminary results from a clinical trial show ultrasound technology treatments yield immediate success in essential tremor (ET), a poorly understood medical condition. Physicians at the University of Virginia (UVA), sponsored by the Focused Ultrasound Surgery Foundation (FUSF), started implementing these groundbreaking sound wave treatments in Feb. 2011. Within months doctors and therapists saw results in 15 individuals who suffer from essential tremor.
What is Essential Tremor?
Essential tremor is a disabling movement disorder that affects a small percentage of the United States’ population. essential tremor is not considered medically dangerous but it does affect an individual’s verbal memory, speech, and name recollection. Because of this, patients with essential tremor may suffer from symptoms such as depression, social phobias, and general poor health due to feelings of helplessness and shame.
“There’s a lot of confusion about what essential tremor is,” said Diane Huss, a UVA Medical Center physical therapist and a member of the research team. “A lot of people confuse the tremor and think patients have Parkinson’s disease instead. essential tremor is very, very much an owner’s disease. In other words, patients grow up living with it, but because it’s progressive, it gets to the point where they can’t feed themselves, and they look for help.”
The Treatment: Ultrasound Technology
Dr. Jeff Elias, a UVA Medical Center neurosurgeon and the principal investigator of the clinical trial learned of the ultrasound technology and immediately saw its promise for essential tremor patients because of its direct and narrow nature.
“[Movement disorders] are located deep within the brain, and this ultrasound device can reach these targets with a lot of precision,” Elias said. “The technology seemed like a perfect application because its transducer can treat things deep in the center of the brain that are outside of the focal area.”
The ultrasound technology targets a patient’s ventralis intermedius (VIM), a part of the brain located in its thalamus region. By focusing on a cluster of cells only a few millimeters in diameter, the sound waves are able to complete a non-invasive lesioning procedure; in other words, according to the report, with the help of visual guidance, “The physician can direct a focused beam of acoustic energy through the patient’s skin, skull, and brain to precisely do a thermal coagulation of the VIM, thereby destroying [the source of the essential tremor] without damaging nearby tissue or the tissues that the beam passes through on its way to the target.”
Huss explained the treatments yield immediate success, and patients are only required to stay overnight in the hospital for observation purposes. Aside from that, Huss said individuals may feel slightly fatigued or tired because of the surgery but their hand function capabilities immediately improve. Without any therapy, the majority of patients are able to write, feed themselves, and brush their teeth without struggle, Huss said.
Because the research is in its clinical trial stage, the team’s primary focus is to assess the safety and efficacy of the technological treatments. Under a US Food and Drug Administration (FDA)-approved protocol, physicians and therapists are working to distinguish any potential risks.
“We need to demonstrate we can do this treatment without inflicting harm,” Huss said. “It’s proved to be extremely successful, as patients have quickly improved without getting hurt or later worsening.”
Huss said the team hopes the improvements will last patients’ lifetimes, but because the ultrasound technology is a treatment, not a cure, they are unsure of how long the success periods will last.
“We’ve found that after three months, people have shown consistent improvement,” she said. “If the tremor does come back, though, we hope patients will be able to at least maintain independence.”
So far, so good. The study’s first 10 patients improved by 78 percent in hand tremor scores and by 92 percent in functional activity performance. In other words, the innovative technology allowed individuals to regain their independence – they can now live normally without assistance.
Overall, patients showed improvement on two tests. The first was the Clinical Rating Scale for Tremor, which considers what a patient’s tremor looks like at rest or at posture when he uses his head, hand, or arm. For example, for this test, a patient is asked to draw spirals and straight lines or pour water from one cup to another, Huss said, and a physical therapist then grades the individual on his skill level. The second test, the Quality of Life in Essential Tremor Questionnaire (QUEST), is a self-assessment that questions how the tremor affects a patient’s ability to feed himself, brush his teeth, or get dressed.
As the first stage of the study concludes, Elias said his team is seeking FDA approval to start the next step: administering the treatments to larger numbers of patients.
“If the FDA gives us approval to continue, we will begin a much larger study to assess the safety and efficacy of this technological treatment,” he said. “We would need approval to continue treating patients, and that will probably come in a couple of years. We’ll see how long it takes, but hopefully in less than 5 years, we’ll be there.”