Addiction next target for ultrasound technology
A trial at West Virginia University is testing the potential of ultrasound treatment in reducing the cravings that are part of drug addiction, writes David Ovalle.
Nestled inside a giant MRI machine in Morgantown, West Virginia, the woman wears a helmet outfitted with special probes. Peering through high-tech goggles, she sees images designed to trigger the awful, familiar cravings that have wrecked her life.
Heroin residue on tin foil. Lines of powder cocaine. Pain pills scattered on a table.
At the same time, scientists buzz around a small observation room, scrutinising brain scans on computer monitors, calibrating measurements, tweaking data points. Beams of ultrasound waves fire into a tiny sector of the woman’s brain by the hundreds – an experimental treatment that researchers hope will essentially reset her mind and ease her cravings for drugs.
The April clinical trial session at West Virginia University’s Rockefeller Neuroscience Institute opens a window into a growing school of research that repurposes a tried-and-true scientific tool, ultrasound, in a more focused fashion.
The use of the high-frequency sound waves is being adapted to treat Alzheimer’s disease, tumours and psychiatric disorders. Now, researchers are studying whether ultrasound can be deployed against an especially implacable foe: addiction to opioids and other substances.
“It’s basically doing brain surgery without the surgery,” said Ali R Rezai, director of the Rockefeller Neuroscience Institute.
Researchers are finishing the initial phase of the clinical trial, funded largely by the National Institute on Drug Abuse. This month, they hope to start the next phase, which will include patients who receive the ultrasound treatment and, crucially, participants exposed only to placebo sound waves, to better gauge the effects of the treatment.
Scientists caution that research into focused ultrasound – including for ailments of the mind, such as substance use disorder – remains in its infancy. They warn that the treatment for addiction is not a cure-all and would be used alongside other therapies. Even if the technology pans out, it could be years before the Food and Drug Administration approves ultrasound for treating addiction.
The challenges were underscored during the session for the 20-yearold woman, who is battling a fentanyl addiction that fuelled multiple overdoses and who was not identified by researchers because of privacy concerns. It was not as simple as flicking a switch. The software, ultrasound machine and MRI used to guide the waves were not designed for this use. So researchers adjusted settings, revving up the system like an old car to reach sufficient wattage.
Amid the hum of the machine and beeps of heart monitors, Rezai analysed readings alongside team members.
“We’re not getting enough dose in her,” Rezai told them.
They zapped her in blocks of five minutes. After each, the woman used handheld controllers to rate drug cravings on a zero to 10 scale, a rough but real-time estimate of the ultrasound’s impact. Her answers flicked on the screen. At one point early on, her desire to use heroin stood at 6.5. For pills, the reading was 9.
They’ve got the power
For decades, researchers aiming to treat neurological and psychiatric conditions have harnessed energy to stimulate the brain. Several methods are used with mixed success.
The oldest, electroconvulsive therapy – ECT – treats major depression, schizophrenia and bipolar disorder by sending electrical currents through the brain, prompting seizures. Another treatment, transcranial magnetic stimulation, or TMS, employs magnetic pulses to stimulate nerve cells in the brain.
With deep brain stimulation, or DBS, surgeons implant a neurostimulator that delivers electrical pulses into the brain. It is approved to treat conditions including essential tremors, Parkinson’s disease and obsessive-compulsive disorder.
During one highly touted study involving deep brain stimulation, researchers at the Rockefeller institute implanted stimulators into a handful of opioid-addicted patients. The results seemed promising, but the centre has pivoted away from that research because major invasive brain surgery is risky and because focused ultrasound may prove safer and more affordable, Rezai said.
In all, the FDA has green-lit focused ultrasound to treat nine conditions, including essential tremor and noncancerous uterine growths. Regulators have approved it for 32 uses worldwide, according to the Focused Ultrasound Foundation, which facilitates and funds research.
Focused ultrasound is being researched and developed for more than 180 uses, said Neal F Kassell, the group’s founder and chairman and a former neurosurgery co-chair at the University of Virginia.
“Ten years ago, there were only three” uses being researched, he said. “That gives you an idea of how rapidly the field is growing.”
At higher intensity, the beams burn away tissue. At low intensity, they can stimulate or restore abnormally functioning tissue. The Rockefeller institute is also involved in trials using low-intensity ultrasound to help the brain better absorb Alzheimer’s medications.
Some 2000 miles (3200 kilometres) away from West Virginia, researchers are also using lowintensity ultrasound, but without the giant MRI. At the University of Utah, researchers invented a headphones-style device that delivers the same low-intensity waves without using an MRI. They are testing it on patients to treat major depressive disorder and expect to soon start trials involving food addiction, opioid use disorder, post-traumatic stress disorder and Alzheimer’s.
The device, dubbed DIADEM, will be more affordable than using “completely impractical” and expensive MRI machines to guide the sound waves, said Jan Kubanek, a Utah neuroscientist helping lead the research who believes the approach has the potential to be used at a large scale.
Participants do not have to shave their