Use of a noninvasive, brainwave-mirroring technology significantly improved heart rate variability (HRV) for a large heterogeneous cohort, in a pilot study conducted at Wake Forest Baptist Medical Center. The study was published in the April 18 online edition of Frontiers in Public Health.

“Negative health outcomes due to the effects of chronic stress are rampant in today’s society,” said the study’s principal investigator, Charles H. Tegeler, MD, professor of neurology at Wake Forest School of Medicine, a part of Wake Forest Baptist.

“The autonomic nervous system drives the body’s response to traumatic stress, such as the sympathetic fight or flight response. The brain manages the autonomic nervous system. The brain has plasticity, can change its pattern of function based on need. Repetitive or severe trauma may cause stress responses to get stuck or persist beyond the period of acute need. Symptoms such as insomnia or diseases such as hypertension may result.”

HRV is an indicator of the dynamic adaptability of the autonomic nervous system. Chronic stress is associated with low HRV, which is, in turn, a risk factor for conditions such as heart disease, diabetes, and death. Few therapies have targeted the brain to improve HRV, Tegeler said.

High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM)—is a noninvasive, closed-loop, acoustic stimulation approach. Computer software algorithms translate specific brain frequencies into audible tones in real time, which are then reflected back via ear buds.

“The recipient’s brain can listen to itself through an acoustic mirror,” Tegeler said. “Likely through resonance between brain frequencies and the acoustic stimulation, the brain is supported to self-adjust towards improved balance and reduced hyperarousal. This allows self-optimization of autonomic stress response patterns that have become rewired or stuck by repetitive traumatic events, whether physical or nonphysical, with no conscious, cognitive activity required.”

This single-site study enrolled 220 participants with an array of neurological, cardiovascular, and psychophysiological conditions, into a single-arm study exploring clinical effects associated with use of HIRREM. Of the enrolled participants, 202 completed the study, and 160 had recordings of blood pressure and pulse that could be analyzed for HRV.

“We observed significantly increased measures of HRV, suggesting greater dynamic adaptability, along with significant improvement in blood pressure, and reduced symptoms of insomnia and depression,” Tegeler said. “There was also correlation between brain pattern and a measure of HRV.”

Limitations of the study include the absence of a control group. It also was an open-label project, meaning that both researchers and participants knew what intervention was received. Future studies evaluating this technology will incorporate a new generation of hardware and software, and be done using randomized clinical trial designs that include a representative comparison group.

HIRREM is registered by Brain State Technologies, based in Scottsdale, Arizona, and has been licensed to Wake Forest Baptist for collaborative research since 2011.