Improvements in Heart Rate Variability, Baroreflex Sensitivity, and Sleep After Use of Closed-Loop Allostatic Neurotechnology by a Heterogeneous Cohort

The U.S. POINTER neurovascular ancillary study: Study design and methods

INTRODUCTION

POINTER Neurovascular (POINTER-NV) is an ancillary study that leverages the rich infrastructure and design of the U.S. Study to Protect Brain Health through Lifestyle Intervention to Reduce Risk (U.S. POINTER) to investigate neurovascular mechanisms that may underlie intervention effects on key brain outcomes.

METHODS

A comprehensive neurovascular assessment is conducted at baseline, Month 12, and Month 24 using a variety of complementary non-invasive techniques including transcranial Doppler ultrasound, carotid ultrasound, echocardiography, tonometry, and continuous blood pressure and heart rate monitoring. Measurements are acquired at rest and during orthostatic challenges, hyperventilation, and carbon dioxide inhalation.

RESULTS

The primary outcomes are baroreflex sensitivity and cerebral autoregulation. Secondary outcomes include aortic, carotid, and cerebral hemodynamics and various measures of autonomic function and vascular structure and function.

DISCUSSION

POINTER-NV will provide critical insight into neurovascular mechanisms that may change with intensive lifestyle modification and promote improvements in cognition and overall brain health.

HIGHLIGHTS

This study takes advantage of U.S. Study to Protect Brain Health through Lifestyle Intervention to Reduce Risk (U.S. POINTER) to address key gaps in the field. POINTER Neurovascular (POINTER-NV) will provide insight into neurovascular mechanisms underlying dementia. POINTER-NV may help shed light on modifiable vascular contributions to dementia.

Noninvasive Assessment of Temporal Dynamics in Sympathetic and Parasympathetic Baroreflex Responses

Background

The baroreflex system is crucial for cardiovascular regulation and autonomic homeostasis. A comprehensive assessment requires understanding the simultaneous temporal dynamics of its multiple functional branches, which traditional methods often overlook.

Objective

To develop and validate a noninvasive method for simultaneously assessing the temporal dynamics of sympathetic and parasympathetic baroreflexes using pulse contour analysis and the sequence method.

Methods

Beat-to-beat blood pressure and ECG recordings were analyzed from 55 preoperative cardiothoracic surgery patients in the supine position and 21 subjects from the EUROBAVAR dataset in both supine and standing positions. Systolic arterial pressure (SAP), interbeat interval (IBI), cardiac output (CO), myocardial contraction (dP/dtmax), and systemic vascular resistance (SVR) were estimated using pulse contour analysis. Baroreflex sensitivity (BRS) was calculated via the sequence method and correlated with hemodynamic and heart rate variability (HRV) parameters.

Results

Parasympathetic BRS for IBI was correlated with the root mean square of successive differences of ECG RR intervals (RMSSD-HRV) at 0-beat delay. Sympathetic BRS for SVR strongly correlated with SVR, CO, and RMSSD-HRV, particularly at 3-beat delay, and was uniquely associated with SAP at 1-beat delay. Sympathetic BRS for dP/dtmax correlated with dP/dtmax at 1-beat delay. In contrast, BRS for CO correlated with CO and SVR at 0- and 3-beat delays. Postural changes mainly affected parasympathetically-mediated BRS for IBI and, to a lesser extent, the sympathetic vascular and myocardial branches.

Conclusions

This method effectively captures multiple baroreflex responses and their temporal dynamics, revealing distinct autonomic mechanisms and the impact of postural changes. Further validation is warranted.

Brain State-Dependent Non-Invasive Neurostimulation with EEG Feedback: Achievements and Prospects (Review)

Non-invasive brain stimulation with electroencephalogram (EEG) feedback is an intensively developing and promising area of neurophysiology. The review considers the literature data over the past 5 years on the achievements and promising directions for the further development of this research line. Modern data on the developed approaches to the practical use of various types of brain state-dependent adaptive neurostimulation with EEG feedback were analyzed. The main attention is paid to the studies using non-invasive magnetic and electrical stimulation, as well as acoustic and audiovisual stimulation. The paper considers the possibilities and prospects for using these technologies in clinical medicine. The results of the authors' own research are presented.

Cereset Research Standard Operating Procedures for Insomnia: A Randomized, Controlled Clinical Trial

Background

Interventions for insomnia that also address autonomic dysfunction are needed.

Objective

We evaluate Cereset Research™ Standard Operating Procedures (CR-SOP) in a pilot randomized, controlled trial. CR-SOP is a less operator-dependent, more generalizable innovation of HIRREM®, a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology demonstrated to improve insomnia and autonomic function.

Methods

Adults with Insomnia Severity Index (ISI) scores of ≥8 were randomized to receive ten sessions of CR-SOP, with tones linked to brainwaves (LB, intervention), or a sham condition of random tones not linked to brainwaves (NL, control). Measures were collected at enrollment and 0-14 days and 4-6 weeks post-allocated intervention. The primary outcome was differential change in ISI from baseline to 4-6 weeks post-intervention. Secondary self-report measures assessed sleep quality65 and behavioral outcomes. Ten-minute recordings of heart rate and blood pressure were collected to analyze autonomic function (heart rate variability [HRV] and baroreflex sensitivity).

Results

Of 22 randomized, 20 participants completed the allocated condition. Intention to treat analysis of change from baseline to the 4-6 week outcome demonstrated mean ISI score reduction of 4.69 points among controls (SE 1.40). In the intervention group, there was an additional 2.58 point reduction in ISI score (SE 2.13; total reduction of 7.27, P = .24). Sleep quality and some measures of autonomic function improved significantly among the intervention group compared to control.

Conclusions

This pilot study compared use of a standardized, allostatic, acoustic neurotechnology intervention with a sham, active control condition. The magnitude of change in insomnia severity was clinically relevant and similar to the findings in a prior, fully powered trial, but the differential improvement observed was not statistically significant. Significant improvements were demonstrated in sleep quality and some autonomic function measures.

Correction of Stress-Induced States Using Sensory Stimulation Automatically Modulated by Endogenous Human Rhythms

This article considers the dynamics of the development of a potential approach to correcting stress-induced states in humans, i.e., adaptive neurostimulation. The approach consists of presenting sensory stimulation automatically modulated by intrinsic rhythmic human processes such as the respiratory rhythm, the heartbeat rhythm, and electroencephalograph (EEG) rhythms. Many examples have shown that real-time self-adjustment of the stimulation parameters by these rhythms leads to a high level personalization of therapeutic stimulation and increases in its efficacy in suppressing stress-induced states. The publications reviewed here point to the advantages of this approach for developing innovatory technologies using complex feedback from endogenous human rhythms to correct a wide spectrum of functional disorders.

Human Body Rhythms in the Development of Non-Invasive Methods of Closed-Loop Adaptive Neurostimulation

The creation and improvement of non-invasive closed-loop brain stimulation technologies represent an exciting and rapidly expanding field of neuroscience. To identify the appropriate way to close the feedback loop in adaptive neurostimulation procedures, it was previously proposed to use on-line automatic sensory stimulation with the parameters modulated by the patient's own rhythmical processes, such as respiratory rate, heart rate, and electroencephalogram (EEG) rhythms. The current paper aims to analyze several recent studies demonstrating further development in this line of research. The advantages of using automatic closed-loop feedback from human endogenous rhythms in non-invasive adaptive neurostimulation procedures have been demonstrated for relaxation assistance, for the correction of stress-induced functional disturbances, for anxiety management, and for the cognitive rehabilitation of an individual. Several distinctive features of the approach are noted to delineate its further development.

Effects of an Allostatic Closed-Loop Neurotechnology (HIRREM) on Brain Functional Connectivity Laterality in Military-Related Traumatic Stress

BACKGROUND AND PURPOSE

Brain asymmetries are reported in posttraumatic stress disorder, but many aspects of laterality and traumatic stress remain underexplored. This study explores lateralization changes in resting state brain network functional connectivity in a cohort with symptoms of military‐related traumatic stress, associated with use of a closed‐loop neurotechnology, HIRREM.

METHODS

Eighteen participants (17 males, mean age 41 years [SD = 7]) received 19.5 (1.1) HIRREM sessions over 12 days. Whole brain resting magnetic resonance imaging was done pre‐ and post‐HIRREM. Laterality of functional connectivity was assessed on a whole brain basis, and in six predefined networks or regions. Laterality of connectivity within networks or regions was assessed separately from laterality of connections between networks or regions.

RESULTS

Before HIRREM, significant laterality effects of connection type (ipsilateral for either side, or contralateral in either direction) were observed for the whole brain, within networks or regions, and between networks or regions. Post‐HIRREM, there were significant changes for within‐network or within‐region analysis in the motor network, and changes for between‐network or between‐region analyses for the salience network and the motor cortex.

CONCLUSIONS

Among military service members and Veterans with symptoms of traumatic stress, asymmetries of network and brain region connectivity patterns were identified prior to usage of HIRREM. A variety of changes in lateralized patterns of brain connectivity were identified postintervention. These laterality findings may inform future studies of brain connectivity in traumatic stress disorders, with potential to point to mechanisms of action for successful intervention.

High-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM) improves symptoms and autonomic function for insomnia: A randomized, placebo-controlled clinical trial

INTRODUCTION

Effective insomnia interventions that also address autonomic dysregulation are lacking. We evaluate high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM® ), in a randomized, controlled clinical trial. HIRREM is a noninvasive, closed-loop, allostatic, acoustic stimulation neurotechnology, to support self-optimization of brain rhythms.

METHODS

One hundred and seven adults (mean age 45.7, SD ± 5.6, 73 women), with Insomnia Severity Index (ISI) scores of ≥15, received ten, 90-min sessions of HIRREM, with tones linked to brainwaves (LB, 56), or random tones not linked to brainwaves (NL, 51), as an active, sham placebo. Outcomes were obtained at enrollment (V1), 1-7 days (V2), 8-10 weeks (V3), and 16-18 weeks (V4) after intervention. Primary outcome was differential change in ISI from V1 to V3. Secondary measures assessed depression (BDI), anxiety (BAI), quality of life (EQ-5D), and a sleep diary. Ten minute recordings of HR and BP allowed analysis of heart rate variability (HRV) and baroreflex sensitivity (BRS).

RESULTS

Of 107 randomized, 101 completed the intervention. Intention-to-treat analysis (107) of change from V1 to V3 revealed a mean reduction of ISI in NL of -4.93 (SE ± 0.76) points, with additional, significant reduction of -2.05 points (0.74) in LB (total reduction of -6.98, p = .045). Additional reduction of -2.30 points (0.76) was still present in the LB at V4 (p = .058). Total ISI reduction from V1 to V4 was -5.90 points for NL and -7.93 points in LB. There were group differences (p < .05) for multiple HRV and BRS measures (rMSSD, SDNN, HF alpha, and Seq ALL), as well as total sleep time, sleep onset latency, and sleep efficiency. There were no serious adverse events.

CONCLUSIONS

Results of this controlled clinical trial showed clinically relevant reduction of insomnia symptoms with HIRREM, over, and above an active, sham control, with associated, durable improvement in autonomic cardiovascular regulation.

Pilot Trial of a Noninvasive Closed-Loop Neurotechnology for Stress-Related Symptoms in Law Enforcement: Improvements in Self-Reported Symptoms and Autonomic Function

Background

Law enforcement officers have decreased life expectancy, attributed to work-related exposure to traumatic stress and circadian disruption. Autonomic dysregulation is reported with traumatic stress and chronic insomnia.

Objective

We explore potential benefits for reduced symptoms related to stress and insomnia and improved autonomic function associated with open label use of high-resolution, relational, resonance-based, electroencephalic mirroring (HIRREM®), in a cohort of sworn law enforcement personnel.

Methods

Closed-loop noninvasive therapies utilizing real-time monitoring offer a patient-centric approach for brain-based intervention. HIRREM® is a noninvasive, closed-loop, allostatic, neurotechnology that echoes specific brain frequencies in real time as audible tones to support self-optimization of brain rhythms. Self-report symptom inventories done before and after HIRREM included insomnia (ISI), depression (CES-D), traumatic stress (PCL-C), anxiety (GAD-7), perceived stress (PSS), and quality of life (EQ-5D). Ten-minute recordings of heart rate and blood pressure allowed analysis of baroreflex sensitivity (BRS) and heart rate variability (HRV).

Results

Fifteen participants (1 female), mean (SD) age 45.7 (5.6), received 12.2 (2.7) HIRREM sessions, over 7.9 in-office days. Data were collected at baseline, and at 22.8 (9.2), and 67.2 (14.1) days after intervention. All symptom inventories improved significantly (P < .01), with durability for 2 months after completion of the intervention. The use of HIRREM was also associated with significant increases (P < .001) in HRV measured as rMSSD and BRS measured by high-frequency alpha index. There were no serious adverse events or drop outs.

Conclusion

These pilot data provide the first report of significant symptom reductions, and associated improvement in measures of autonomic cardiovascular regulation, with the use of HIRREM in a cohort of law enforcement personnel. Randomized clinical trials are warranted.

The Rhythmic Finger Focus Hypnotic Technique: Multilevel Application of Ericksonian Utilization

This paper presents a hypnotic technique that starts with a suggested focus on one's fingertips, and movement of the hands in a self-determined rhythm. The technique involves the use of the utilization principle of Milton Erickson in multiple ways. This includes utilizing psychomotor agitation characteristic of psychophysiological arousal, directing it toward movement that generates the sensations upon which to focus. It utilizes the sensitivity of the fingertips, the high degree of representation of the hands in the somatosensory cortex, and the tendency of the brain to orient to novelty to help facilitate focused absorption. It generates counter stimulation for pain management, and emotionally self- soothing tactile sensations. The technique is further designed to activate and utilize prior sensorimotor learning and sensory experiences associated with the hands to access feelings of mastery, creativity, flow, self-efficacy, and other positive emotional experiences. It is hypothesized that multisystem coherence is generated through activating prior positive motor, behavioral and affective experiential learning. It is further hypothesized that the rhythmic movement and sensory input simultaneously generated by and processed in the right and left hemispheres, entrains the hemispheres toward greater sympathetic/parasympathetic balance.