By Dennis Thompson
The therapy initially reads brain activity through scalp sensors. That activity is then converted into a series of audible tones. The tones are then reflected back to the brain through earbuds in a matter of milliseconds, explained Dr. Charles Tegeler, a professor of neurology with Wake Forest School of Medicine in Winston-Salem, N.C.
"Your brain gets to listen to the song that it's playing. It gets to look at itself in an acoustic mirror," said Tegeler, who served as senior researcher for both studies.
"Somehow that rapid update gives the brain a chance to auto-calibrate, self-optimize, relax and reset," Tegeler said.
One study found that 10 men and women achieved significant reductions in their blood pressure after going through an average of nearly 18 sessions over about 10 days.
These patients achieved an average reduction in their systolic blood pressure -- the top number -- from 152 to 136. The diastolic pressure -- the bottom number -- went down from an average of 97 to 81. Normal blood pressure is 120/80 mm Hg or lower, according to the U.S. National Heart, Lung, and Blood Institute.
Dr. Raymond Townsend, a professor and director of the hypertension program at Penn Medicine, said the reduction created by this technology is on par with that achieved using blood pressure medication.
"This is not a drug, and it's not technically anything invasive," said Townsend, who is the American Heart Association's Physician of the Year for 2016.
"If you can produce a sustained reduction in blood pressure by something like this, especially of this magnitude, you've got my interest," Townsend said.
In the other study, researchers examined 52 adult migraine sufferers, providing them almost 16 sessions on average over nine days.
The sound therapy appears to help realign the autonomic nervous system by providing a form of biofeedback, said Dawn Buse, director of behavioral medicine at Montefiore Headache Center in New York City.
The autonomic nervous system unconsciously controls the function of internal organs, and regulates body functions such as heart rate, digestion and respiration.
"It is exciting to see novel work being done which may ultimately yield new effective treatment options to improve the lives of those living with migraine," Buse said.
The therapy is called high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM). It has been tested on about 400 people in a series of studies, Tegeler said.
Previous results have shown that it can help treat people with insomnia, depression and stress anxiety. Ongoing studies are investigating its usefulness in treating post-traumatic stress disorder and symptoms of traumatic brain injury, Tegeler noted.
The scalp sensors detect electrical imbalances in the left and right sides of the brain. The sensors then reflect those imbalances through tones that grow more or less intense to reflect electrical activity, the researchers said.
"The brain on the right side begins to hear in the right ear what it's doing, and the brain on the left side is hearing via the left ear what it's doing," Townsend said.
"Apparently the brain is smart enough to say, 'Hey, wait a minute -- the right ear is louder than the left ear or different or more intense than the other side,' and it begins to auto-regulate," he explained.
The autonomic nervous system plays a role in maintaining blood pressure, but doctors have been at a loss how to use it to treat high blood pressure, Townsend said.
It has two branches -- the sympathetic nervous system and the parasympathetic nervous system that continually work at odds with each other, Townsend said. The sympathetic system governs the "fight or flight" response, while the parasympathetic system governs the "stand or freeze" or "rest and digest" response, he said.
In blood pressure patients treated with HIRREM, "you see a little drop in the sympathetic and an increase in the parasympathetic, and that makes sense for seeing the changes in blood pressure that are reported here," Townsend said.
Buse said similar biofeedback techniques also are used in migraine management, to help improve the flexibility and resiliency of the autonomic nervous system.
The sessions take a "not inconsequential amount of time," about 90 minutes for each, Townsend noted.
However, the patient is not consciously taking part in the process, and can do other things while listening to the tones -- read a book, solve puzzles or even take a nap, Tegeler said.
"This is different than many other therapies out there because there is no conscious cognitive [mental] activity required," Tegeler said. "There is no learner in the loop."
The research was funded by a grant from the Susanne Marcus Collins Foundation Inc.
The two studies were scheduled for presentation Thursday and Friday at the American Heart Association's meeting in Orlando. Findings presented at meetings are generally viewed as preliminary until they've been published in a peer-reviewed journal.