A Phase 2/3 interventional study of HRV Coherence Ratio and NSI in Autonomic Nervous System Disease, Concussive Injury and Mild Traumatic Brain Injury, sponsored by Virginia Commonwealth University. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-09-22.
Sponsored by Virginia Commonwealth University · Phase 2/3, Interventional, and Treatment
Many combat veterans (c-Vs), service members (SMs) and civilians with mild traumatic brain injury (mTBI, also termed concussion) suffer from persistent post-concussion symptoms (PPCS) that degrade physical and cognitive well-being and have been linked with early neurodegeneration. PPCS include somatosensory (e.g., headache, disturbed vision), vestibular (e.g., dizzy, clumsy), cognitive (e.g., executive function, memory) and affective symptoms (e.g., sleep disturbance, irritability, depression). A key pathological process that provokes and perpetuates PPCS is autonomic nervous system (ANS) dysfunction such as unremitting sympathetic nervous system activation that also exacerbates other pathology such as inflammation. ANS activity can be readily quantified by measuring heart rate variability (HRV), or the variation in heart rate over time, which serves as a valid index of both physiological and psychological health
This study, a randomized, controlled trial (RCT) of an easily implemented, mechanism-driven, behavioral intervention using HRV biofeedback (HRV-B) to treat PPCS among adults, including c-Vs and SMs, with history of single or repeated mTBI from blast-related or other mechanism. Specifically, we study an intervention for persons with PPCS that promotes sustained functional recovery during the chronic phase of injury, which addresses psychological health and cognitive functioning, and has the potential to address neurodegenerative processes associated with TBI and treat co-occurring TBI and psychological health conditions. Importantly, the intervention is non-invasive, rapidly deployable, and is based on the pathophysiology and a theoretical mechanism of PPCS. Secondarily, this project also has the potential as a more generalized solution to increase readiness and psychological resilience in individuals, small teams, families, and communities to ameliorate the potential negative impacts of specific military and life stressors.
637 studies on the registry are indexed under Brain Concussion; 163 are open to participants now.
This study's planned enrollment of 148 is above the median of 63 across 446 interventional studies indexed under Brain Concussion.
Browse Brain Concussion studies →Virginia Commonwealth University is the lead sponsor of 648 studies on the registry; 80 are open to participants now.
Of its 90 completed or terminated interventional studies of FDA-regulated products, 64 (71%) have results posted.
Counted across the registry records on this site, refreshed daily.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Behavioral intervention using HRV biofeedback (HRV-B) to treat Persistent Post-Concussion Symptoms (PPCS) among adults, including Combat Veterans (c-Vs) and Service Members (SMs), with history of single or repeated mTBI from blast-related or other mechanism.
Other: HRV Coherence Ratio · Behavioral: NSI · Behavioral: Pittsburgh Sleep Quality Index (PSQI) · Behavioral: Quantitative Sleep Measures · Behavioral: Patient Global Impression of Change (PGIC) · Behavioral: Cognitive Performance/NIH Toolbox Cognitive Battery · Other: Pain Interference/TBI-QoL Pain Interference Short-Form · Behavioral: Patient Health Questionnaire-9 (PHQ-9) · Behavioral: PTSD Checklist for DSM-5 (PCL-5) · Other: HRV Biofeedback (HRV-B)
Psychoeducational treatment
Other: HRV Coherence Ratio · Behavioral: NSI · Behavioral: Pittsburgh Sleep Quality Index (PSQI) · Behavioral: Quantitative Sleep Measures · Behavioral: Patient Global Impression of Change (PGIC) · Behavioral: Cognitive Performance/NIH Toolbox Cognitive Battery · Other: Pain Interference/TBI-QoL Pain Interference Short-Form · Behavioral: Patient Health Questionnaire-9 (PHQ-9) · Behavioral: PTSD Checklist for DSM-5 (PCL-5) · Other: Psychoeducational (Edu) Comparator Intervention
Evaluates autonomic function and the intervention process's efficacy, specifically resonance frequency breathing. The HRV Coherence Ratio will be quantified using a non-invasive procedure during resonance frequency breathing conditions and a standardized definition.
This inventory assesses the overall symptom burden, including post-concussion symptoms, on a 5-point scale. It is a well-established measure used by the Department of Defense (DoD) and VA and in mTBI outcome research at large, and includes 27 items that capture vestibular, somatosensory, cognitive, and affective symptoms.
It includes seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disturbances, use of sleeping medication, and daytime dysfunction. Higher PSQI scores indicate poorer sleep quality.
Measured using wrist actigraphy, which provides objective data on sleep parameters such as sleep latency, duration, efficiency, fragmentation, and wake time after sleep onset (WASO). Participants will wear the actigraphy monitors at baseline, post-training, and follow-up assessments.
It evaluates patients' perceptions of clinically meaningful changes in their condition following the intervention. It is considered the gold standard for such assessments.
Assessed using the NIH Toolbox Cognitive Battery, which measures executive function, episodic memory, working memory, processing speed, language, attention, and reading through a brief, computer-based test
Evaluated using the TBI-QoL Pain Interference Short-Form, a 10-item questionnaire that measures the extent to which pain interferes with daily activities and overall quality of life. Each BPI-I item is scored from 0="Does not interfere" to 10="Completely interferes," and the scale score is the mean of the 7 items. Scores range from 0 to 10 with higher scores indicating greater pain interference.
Assesses the severity of depressive symptoms over the past two weeks. Scores less than 5 almost always signified the absence of a depressive disorder; scores of 5 to 9 predominantly represented patients with either no depression or subthreshold (i.e., other) depression; scores of 10 to 14 represented a spectrum of patients; and scores of 15 or greater usually indicated major depression.
The PCL-5 (PTSD Checklist for DSM-5) is a screening tool that assesses the presence and severity of PTSD symptoms according to DSM-5 criteria. It's not a diagnostic tool itself but helps clinicians determine if further evaluation is needed. Scores range from 0 to 80, with higher scores indicating more severe symptoms.
participants will receive weekly biofeedback training over a six-week period. Each session includes approximately 30-40 minutes of biofeedback training where participants are affixed with HRV monitoring equipment. They will be guided to synchronize their heart rate variability (HRV) through slow diaphragmatic breathing and focusing on positive emotions. This process involves viewing real-time HRV patterns on a computer monitor, with coaching to help participants achieve resonant frequency breathing.
Six weekly meetings 30-40 minutes, viewing standardized educational content on concussion recovery. No information on breathing will be provided to participants in the Edu group.
Neurobehavioral Symptom Inventory (NSI)
The Neurobehavioral Symptom Inventory (NSI) is a 22-item self-report questionnaire used to assess the severity of neurobehavioral symptoms following traumatic brain injury (TBI), particularly postconcussion symptoms. It's a widely used tool in TBI research and clinical evaluation by the Department of Defense and Department of Veterans Affairs. The total score ranges from 0 to 88, with higher scores indicating more severe post-concussive symptoms
Time frame: Baseline to end of study procedures (11 weeks)
Heart Rate Variability Biofeedback (HRV-B)
It is a biofeedback technique that trains individuals to regulate their heart rate variability (HRV) through breathing exercises. It aims to improve self-regulation, reduce stress, and enhance overall well-being by strengthening the parasympathetic nervous system. HRV varies depending on age, fitness level, and overall health, and falls between 60 and 100 ms for most individuals. However, it is important to note that a "good" HRV may differ from person to person based on their individual circumstances.
Time frame: Baseline to end of study procedures (11 weeks)
NIH Toolbox Cognitive Battery
Assessed using the NIH Toolbox Cognitive Battery, which measures executive function, episodic memory, working memory, processing speed, language, attention, and reading through a brief, computer-based test
Time frame: Baseline to end of study procedures (11 weeks)
TBI-QoL Pain Interference Short-Form
Evaluated using the TBI-QoL Pain Interference Short-Form, a 10-item questionnaire that measures the extent to which pain interferes with daily activities and overall quality of life. Each BPI-I item is scored from 0="Does not interfere" to 10="Completely interferes," and the scale score is the mean of the 7 items. Scores range from 0 to 10 with higher scores indicating greater pain interference.
Time frame: Baseline to end of study procedures (11 weeks)
Patient Health Questionnaire-9 (PHQ-9)
Patient Health Questionnaire-9 (PHQ-9) Assesses the severity of depressive symptoms over the past two weeks. Scores less than 5 almost always signified the absence of a depressive disorder; scores of 5 to 9 predominantly represented patients with either no depression or subthreshold (i.e., other) depression; scores of 10 to 14 represented a spectrum of patients; and scores of 15 or greater usually indicated major depression
Time frame: Baseline to end of study procedures (11 weeks)
PCL-5 (PTSD Checklist for DSM-5)
The PCL-5 (PTSD Checklist for DSM-5) is a screening tool that assesses the presence and severity of PTSD symptoms according to DSM-5 criteria. It's not a diagnostic tool itself but helps clinicians determine if further evaluation is needed. Scores range from 0 to 80, with higher scores indicating more severe symptoms.
Time frame: Baseline to end of study procedures (11 weeks)
Plan to share: No
No publications or documents are linked to this record.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Virginia Commonwealth University →