For people with chronic insomnia, a good night’s sleep is elusive. But what if insomnia symptoms could be alleviated by simply listening to one’s own brainwaves?
Researchers at Wake Forest Baptist Health conducted a clinical trial that showed reduced insomnia symptoms and improved autonomic nervous system function using a closed-loop, acoustic stimulation neurotechnology.
The study is published in the September 17 online edition of the journal Brain and Behavior.
High-resolution, relational, resonance-based electroencephalic mirroring (HIRREM) uses scalp sensors to monitor brainwaves and software algorithms to translate specific frequencies into audible tones of varying pitch in real time.
These tones linked to brainwaves are echoed back instantaneously via ear buds. This allows the brain a chance to listen to itself, to look at itself in an acoustic mirror.
“Sleep is foundational for optimal health, healing and well-being,” said principal investigator Charles H. Tegeler, M.D., chair of neurology at Wake Forest School of Medicine, part of Wake Forest Baptist Health.
“HIRREM is a unique non-drug, noninvasive, acoustic neuromodulation intervention that supports the brain to balance and quiet itself. Our results show durable benefit for both reduced symptoms of insomnia and significantly improved objective measures of autonomic function.”
HIRREM technology supports the brain to self-adjust, to reset from what may have become stuck trauma and stress patterns, believed to contribute to insomnia, Tegeler said.
The brain pattern is observed to shift toward improved balance and reduced hyperarousal with no conscious, cognitive activity required.
According to the American Academy of Sleep Medicine, about 30 to 35% of Americans have experienced insomnia, which can reduce life expectancy and increase the risk of cardiovascular events, obesity, diabetes and other illnesses.
The study included 107 adult men and women with moderate to severe insomnia. Approximately half received the HIRREM intervention, and the placebo group received an active intervention of random tones.
All participants kept a daily sleep diary, and each received 10, 60-minute intervention sessions (either HIRREM or placebo), over a three-week period.
In the study, changes were recorded on the Insomnia Severity Index (ISI), a self-reporting instrument to assess insomnia symptoms.
Researchers also recorded heart rate and blood pressure to objectively analyze autonomic cardiovascular regulation.
After completion of the intervention sessions and at follow-up visits up to four months later, subjects in the HIRREM group reported clinically meaningful reductions for insomnia symptoms. Four months following the intervention, 78% of those receiving HIRREM reported no significant insomnia symptoms.
They also showed significant, durable improvements in autonomic function across multiple objective measures of heart rate variability (HRV) and baroreflex sensitivity (BRS) compared to those who received random tones.
HRV is a powerful biometric that reflects the health of the autonomic nervous system, and BRS measures blood pressure regulation.
In this study, the HIRREM participants were five times more likely than placebo to have improvement in their HRV measured as rMSSD by more than 50%. They were also twice as likely to have improved BRS by more than 50% compared to placebo.
These changes may lead to long-term improvement in the cardiovascular health of the participants, Tegeler said. There were no serious adverse events, and less than 6% of study participants dropped out.
“These findings add to the rapidly growing interest in neuromodulation and demonstrate that a brief intervention with closed-loop acoustic stimulation can improve sleep in a meaningful way, while also improving autonomic function,” Tegeler said.
“It’s an important alternative approach for people who suffer from insomnia.”
Funding: This study was supported by a research grant from The Susanne Marcus Collins Foundation, Inc.
HIRREM, the legacy technology of Cereset, was developed and licensed by Brain State Technologies of Scottsdale, Ariz.
A major challenge for law enforcement officers is their near continuous exposure to stressors, putting them at significant risk for compromises in their health and performance. A report from the Buffalo Cardiometabolic Occupational Police Stress (BCOPS) study found that for white male police officers in Buffalo, New York average life expectancy was 21.9 years lower than for the white male general US population.1
Among potential causes for the discrepancy, the authors cited repeated stress exposures, including an estimated 7% to 19% prevalence of posttraumatic stress disorder (PTSD), and also biological circadian rhythm disruption due to shift work.
Similarly, in a review of cardiovascular health risks in law enforcement, Zimmerman pointed to physical and psychological stresses including shift work, as being risk factors for hypertension, dyslipidemia, obesity, and diabetes.2
Importantly, sleep disturbance is highly associated with exposure to chronic stress3 and trauma,4 and evidence shows that sleep, as such, is a critical factor in the health and performance of individuals working in high stress environments.
Gehrman et al. found that among military service members deployed to the Middle East after the 9/11 terror attacks, predeployment insomnia symptoms were a significant risk factor for postdeployment diagnosis of PTSD. Interestingly, the increased risk for subsequent PTSD related to predeployment symptoms of insomnia was almost as strong as their measure for combat exposure.5
Hartley et al. noted that the percent of police officers with depression was roughly double that for the general population.6 It was reported that officers in this study were almost 4 times more likely to get less than 6 hours of sleep in a given 24-hour period than the general population.
Furthermore, a study of US and Canadian police officers found that 40% screened positive for at least 1 sleep disorder (sleep apnea, insomnia, or shift work disorder). Those who screened positive had higher odds to report that they had made a serious administrative error, fallen asleep while driving, made an error or safety violation related to fatigue, had uncontrolled anger toward suspects, or fallen asleep during meetings.7
The National Law Enforcement and Corrections Technology Center also found that over half of officers fail to maintain healthy sleep patterns and 90% report being routinely fatigued on the job.8
Neurobiological pathways are believed to mediate or amplify the effects of stress, circadian rhythm disruption, and sleep disturbance on health and performance.
This includes both the functionality of the neuroendocrine axis9 and the autonomic nervous system. In particular, interactions between the sympathetic (“fight-flight”) and parasympathetic (“rest-digest-freeze”) divisions are of interest.10 Dysregulated activity of the sympathetic and parasympathetic divisions are increasingly a focus for studies involving stress in law enforcement officers.
These may be expressed as a dampening or decrease of heart rate variability (HRV) or baroreflex sensitivity (BRS). HRV, or variability in the beat-to-beat interval between heart contractions, indicates the capacity of the cardiovascular system to make dynamic adjustments to cardiac output, in the context of instantaneous and anticipated environmental needs.
In general, greater HRV and BRS indicate a higher capacity for the parasympathetic division to modulate or buffer the arousal of the sympathetic division, while lower HRV is a risk factor for adverse health and performance outcomes.11,12
In the BCOPS study, HRV was shown to vary inversely with insulin levels in a cross-sectional analysis (n = 355) of nondiabetic police officers.13 The same team found that HRV was inversely related to the exposure of perceived lack of support, in female officers.14
These data indicate that stress, sleep disturbance, and autonomic dysregulation present a major challenge to the health, well-being, and operational performance of law enforcement officers. As yet there is no evidence pointing to robust, acceptable, brief, durable, and cost-effective interventional strategies for helping law enforcement personnel to simultaneously optimize their sleep quality and attenuate adverse tendencies in autonomic nervous system activity.
Given its central role with sleep, and with managing autonomic responses to traumatic stress, brain-focused approaches appear to offer an attractive target for therapeutic interventions.
High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®) is a noninvasive, closed-loop, allostatic, brain echoing neurotechnology developed, registered to, and licensed by Brain State Technologies, LLC, Scottsdale, Arizona, to support autocalibration of neural oscillations.
Scalp sensors observe brain frequencies and amplitudes in real time, and software-guided algorithms identify and translate selected brain frequencies into audible tones to support real-time self-optimization of brain activity.15 The audible tones are echoed back to the recipient via ear buds bilaterally, simultaneously, in 4 to 8 milliseconds. This provides an opportunity for the recipient to, figuratively speaking, listen to their brain.
The rapid updating regarding its own pattern, and resonance between the audible tones and oscillating brain networks, provides the brain a chance to auto-calibrate, self-adjust, “relax,” and reset/get unstuck from what have been persisting stress/trauma response patterns.
The brain electrical patterns are observed to shift independently, with no conscious, cognitive activity required, no operant conditioning, and no learner in the loop, toward improved balance and reduced hyperarousal. Such acoustic neuromodulation with the associated increase in flexibility and dynamic range of response might be expected to translate into health benefits such as reduced symptoms and improved downstream autonomic cardiovascular regulation.
The use of HIRREM has been associated with reduced sleep symptomatology and reduced high-frequency amplitudes in adults with insomnia,16 reduced menopausal symptoms in women,17 improved sleep in athletes with persisting postconcussion symptoms,18 reduced symptoms, and temporal lobe high-frequency asymmetry in self-reported posttraumatic stress,19 and reduced symptoms of military-related traumatic stress.20
Improved autonomic cardiovascular regulation has been observed in a large heterogeneous cohort of those receiving HIRREM.21 In addition, correlation has been reported between high-frequency electrical brain pattern asymmetry scores at baseline and measures of autonomic cardiovascular regulation.22
Moreover, improved network connectivity on whole-brain rest magnetic resonance imaging was observed in participants with military-related traumatic stress.23 Finally, in a controlled trial of HIRREM for moderate to severe insomnia (auditory tones linked to brainwaves vs random tones), there was not only added benefit with the active intervention to reduce symptoms, but significant increases were also observed in multiple objective measures of autonomic cardiovascular regulation, with durability to 4 months post-HIRREM.24,25
Based on previous experience, the hypothesis was that the use of HIRREM by law enforcement personnel would be associated with reduced symptoms and improved autonomic function. The current report explores the effects of the open label use of HIRREM on autonomic cardiovascular regulation and self-reported symptoms in a cohort of law enforcement personnel.
Discussion
Chronic stress and sleep disruption experienced by those in law enforcement is associated with increased risk for a variety of adverse health outcomes.1,2,8 Although most assume that acute incidents are the main culprit, stress in law enforcement can be due to a variety of organizational, operational, external, and personal factors.40
Irrespective of the causes, the need for therapeutic strategies to reduce symptoms, improve sleep, and improve autonomic balance and function is clear.
This study evaluated changes in a variety of self-reported behavioral symptoms, and autonomic cardiovascular regulation, associated with the use of HIRREM in a sworn law enforcement cohort. There were significant improvements from baseline to post-HIRREM follow-up visits for self-reported symptoms of insomnia, depression, traumatic stress, perceived stress, anxiety, and quality of life.
There was also improvement in objective measures of autonomic function as measured by HRV and BRS. The autonomic changes appear to primarily reflect increased parasympathetic tone, resulting in greater flexibility and dynamic range for autonomic responses. The benefits for both symptom reductions and improved autonomic function were durable to just over 2 months following completion of HIRREM.
The impact of stress with law enforcement is well recognized, and many therapeutic strategies have been evaluated. A Cochrane review reported on 10 studies that tested psychosocial interventions for police, including physical exercise, as potential ways to prevent psychological disorders including stress-related symptomatology.
The authors concluded that “There is lack of evidence that psychosocial interventions can reduce stress-related psychological symptoms.”41 They noted that only one of the studies was focused on primary prevention (intervention to prevent the onset of disease), and that the studies were focused on the stress of acute incidents, as opposed to organizational, continuous, and perhaps more consequential stresses of the general law enforcement work environment.
Others have since reported on the use of a variety of team-based, individual, cognitive, and physiological-based approaches. Kuehl et al. studied the effectiveness of a team-based strategy. The intervention consisted of a series of scripted, peer-led sessions on healthy eating, exercise, body weight, stress, sleep, and other lifestyle behaviors. Benefits were seen at 6 months;42 but at the 12-month follow-up, only the differences for healthy eating habits remained.43
Using a cognitive strategy with a focus on mental imagery, Arnetz et al. found that police cadets (n = 37) who participated in a 9-week resilience training course reported better general health and more problem-based coping skills. This persisted through 2 years of follow-up, compared to a control group (n = 38) who did not take the course.44
Eight weeks of a Mindfulness-Based Resilience Training program resulted in initial reductions in salivary cortisol, self-reported aggression, organization stress, burnout, sleep disturbance, but was not maintained at the 3-month follow-up.45 A brief, group-based fatigue management training program also improved self-reported insomnia at 4 weeks, but did not affect other behavioral symptoms, and there was no evaluation of impact on autonomic function.46
McCraty and Atkinson reported on their controlled study to promote resilience in police officers through emotional management training and HRV biofeedback (HeartMath®), provided over 3 separate classroom sessions lasting 4 hours each.47 Postinterventional differences between the groups were mostly nonstatistically significant, and there were no stated changes in physiological measures that could be attributed to the training. Other studies using variants of the HeartMath technique have shown modest changes in nonrandomized designs.48–50
Limitations of our study, which preclude making definitive conclusions, include the small sample size, and a single-arm, open label design. In addition, the beneficial effect of participating in a clinical research study as well as the impact of therapeutic expectation cannot be adequately evaluated in this study.
In a previous controlled clinical trial of HIRREM for insomnia, expectation effect did not result in improved autonomic function for the control group who received random tones not linked to brainwaves. However, significant improvement was observed in the active intervention group, as was seen in the current cohort.
This suggests that measurable, persisting physiological shifts occurred. This cohort consisted of all sworn personnel, virtually all of whom were officers, reflecting potential recruitment bias, so generalizability to patrolmen and nonsworn personnel cannot be assessed. A longer period of follow-up to better evaluate durability would be desirable.
reference link : https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7218336/
