Focused ultrasound (FUS) operates by an analogous principle to “using a magnifying glass to focus beams of sunlight on a single point to burn a hole in a leaf,” notes the Focused Ultrasound Foundation. “With focused ultrasound, an acoustic lens is used to concentrate multiple intersecting beams of ultrasound on a target deep in the body with extreme precision and accuracy,” it adds.
Among the conditions that FUS can treat the foundation adds, is essential tremor, a neurological disorder that causes involuntary trembling. “It can affect almost any part of your body, but the trembling occurs most often in your hands — especially when you do simple tasks, such as drinking from a glass or tying shoelaces,” according to the Mayo Clinic.
Focused ultrasound, which is FDA-approved for essential tremor, provides a noninvasive treatment, which doesn’t require anesthesia, scalp incisions, holes in the skull, nor electrodes attached to the brain, the foundation states. “The highly precise treatment uses focused beams of acoustic energy to heat and destroy target cells without harming adjacent tissue.”
That’s not how Michael Okun, chair of neurology at the University of Florida, sees it though. Treating essential tremor with focused ultrasound “is like trying to make an omelet without opening the egg,” Dr. Okun told Medpage Today. “You’re shooting from outside the brain.”
Even missing a small mark by a little bit could carry “harmful side effects,” Medpage reports. “A wrongly mapped attempt to ease a tremor in an arm, for example, could weaken a leg, leaving a patient unable to walk.”
Dr. Okun spoke to Medpage ahead of a debate at the 2017 American Academy of Neurology meeting, in which he took the “con” side of FUS, and Paul Fishman, a University of Maryland neurologist, took the “pro” side.
After the debate, the audience was asked to vote. “Okun’s arguments ‘con’ won with 90 percent of those voting, but most audience members didn’t raise their hands for either one, suggesting that they found both sides persuasive,” Medpage reported. The article concluded, “It’s simply too early to dismiss it or embrace it.”
To read the Focused Ultrasound Foundation’s page on osteoarthritis — where FUS use is “still in the early stages,” it says — click here.