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Persistent Post-concussive SyndromePhase 2HOINPCSNCT05173818

Hyperbaric Oxygen Effects on Persistent Post-concussive Symptoms

A Phase 2 study testing Hyperbaric oxygen at 1.5 ATA in people with Persistent Post-concussive Syndrome and Concussion Post Syndrome, run by Essentia Health at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Persistent post-concussive symptoms (PPCS) are a source of significant burden among a subset of patients with concussion with prevalence rates previously reported between 11 - 82% based on timing of assessment, diagnostic criteria, or population under study. Read more about this study

Who is it for?
Ages 18 years and older
What is being tested?
Hyperbaric oxygen at 1.5 ATA
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
20 participants
Where
1 siteUnited States
Study dates
28 Jun 2022to 1 Aug 2025
Phase
Phase 2
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Volunteers must have a history of mild traumatic brain injury, specifically, persistent post-concussive symptoms after examination by a neuropsychologist or neurologist.
  • Volunteers time from concussive incident (Mild traumatic brain injury) must be between 3 months - 5 years following head trauma incident
  • TBI was caused by non-penetrating trauma
  • Volunteers must have current complaints of TBI symptoms such as headache, dizziness, or cognitive or affective problems
  • Volunteers must be 18-year-old or more
  • Willing and able to provide informed consent
Show all 11Show fewer
  • Able to speak and read English, as primary language
  • Agrees to provide blood samples for clinical lab tests
  • Willing and committed to comply with research protocol and complete all outcome measures
  • Able to equalize middle ear pressures or willing to undergo needle myringotomies if needed
  • Willingness and committed to comply with study protocol outlined reproductive plan based on baseline reproductive status

Who cannot join

  • Prior treatment with hyperbaric oxygen treatment
  • Hyperbaric chamber inside attendant, professional, SCUBA diver (technical, commercial, operational/military or recreational)
  • The investigators will exclude pregnant women from this study because potential fetal adverse reactions triggered by high oxygen partial pressures such as retrolenticular fibroplasia though careful review of human data are generally reassuring such as the use of hyperbaric oxygen to treat acute carbon monoxide poison in the pregnant patient.13
  • Prisoners
  • Minors
  • Unable to protect airway or requires frequent suctioning
Show all 21Show fewer
  • Known or suspected peri-lymphatic fistula
  • Presence of tracheostomy (due to limitations in auto-inflating the middle ear)
  • Unable to participate fully in outcome assessments
  • Unable to cooperate with hyperbaric oxygen treatments
  • Unable to speak and read English, as primary language
  • Not cooperating with instructions during hyperbaric oxygen treatments such as bringing contraband items into the chamber (such as fire lighter)
  • Not competent to sign their own consent. Such potential participants will not have the capacity to participate in a full range of neurocognitive testing
  • Pre-existing diagnosis of a psychotic disorder(s): schizophrenia, bipolar, dissociative disorder
  • History of moderate or severe traumatic brain injury
  • History of brain injury not of traumatic etiology such as stroke or drug-induced coma
  • Verifiable diagnosis of learning disability. Other pre-existing cognitive issues may make it difficult for potential participants to fill out certain outcome assessments such as neurobehavioral symptomatic inventory. This could lead to measurement bias or confound the result.
  • Claustrophobia and unwilling to enter hyperbaric chamber
  • Untreated pneumothorax
  • Presence of implanted device with un-verifiable test to pressure by manufacturer
  • Concurrent enrollment in an alternate interventional trial for post concussive symptoms

Trial locations and contacts

1 site in 1 country.

United States1 site

  • Essentia Health

    Fargo, North Dakota, 58103

Other trials in United States

About this study

Official title: Effect of Hyperbaric Oxygen on Persistent Post-concussive Symptoms After Mild Traumatic Brain Injury

Persistent post-concussive symptoms (PPCS) are a source of significant burden among a subset of patients with concussion with prevalence rates previously reported between 11 - 82% based on timing of assessment, diagnostic criteria, or population under study.

Examples of persistent post-concussion symptoms include balance problems, headaches, fatigue, poor concentration, forgetfulness, anxiety, irritability, and sleep disturbance. Few proposed therapies have proved successful in the management of persistent post-concussion symptoms following mild traumatic brain injury.

Read more

The investigators will explore hyperbaric oxygen administered in a randomized sham-controlled clinical trial as an effective and tolerable treatment in improving neuropsychological status among adult patients with persistent post-concussive symptoms.

The overall hypothesis to be evaluated is that hyperbaric oxygen improves neuropsychological status and a serum concussion biomarker associated with PPCS.

Read the detailed description

This is a parallel, randomized, double-blinded and sham-controlled study. A total of 100 subjects will be randomly assigned to either an intervention arm: 50 participants exposed to > 99.9% oxygen at 1.5 atmosphere absolute for 60 minutes over 40 treatments or sham-treatment arm: 50 participants exposed to oxygen and pressure composition equivalent to breathing atmospheric air for 60 minutes over 40 treatments.

This study is designed to determine whether hyperbaric oxygen improves neuropsychological status and ameliorates symptoms in adults with persistent post-concussive symptoms (PPCS) following mild traumatic brain injury. It recruits from either military or civilian population; uses a validated screening tool - Repeatable battery for the assessment of neuropsychological status (RBANS)- used in dementia and other forms of brain injury not used hitherto, in previous randomized control trial that investigated the effectiveness of hyperbaric oxygen in the management of PPCS. It also includes a concssuon biomarker, as an objective secondary endpoint.

The study is based on repeated measure design. The study will describe and track changes in the outcomes of interest over time, and examine associations between measures within each participant and across certain participant characteristics.

Being tested
Hyperbaric oxygen at 1.5 ATA, Sham treatment
Keywords
Hyperbaric oxygen treatment, Neurofilament light chain, RBANS
Medical subject headings
Post-Concussion Syndrome, Charcot-Marie-Tooth disease, Type 1F

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Hyperbaric oxygen at 1.5 ATADrug

    Also called 1.5 ATA

    Hyperbaric oxygen (HBO2) at 1.5 ATA (active) group (hyperbaric oxygen-chamber compressed to 1.5 atmosphere absolute and breathing >99.9% oxygen). Each participant should complete 40 sessions, one session per day, five per week over the course of 3 months.

  • Sham treatmentDrug

    Also called 1.2 ATA then changed to 1.0 ATA

    Sham treatment includes pressurizing the chamber to 1.2 ATA with air for 5 minutes with noise of circulating air, return the chamber to 1.0 ATA after 5-7 minutes and maintain it at that pressure for until the end of the treatment, with noise of circulating air. Internal control knobs will be concealed. Participants will be instructed to undergo intermittent ear clearing technique during the initial 5 minutes of "descent"

Study groups in NCT05173818
Study groupRoleWhat they receive
HBO at 1.5 Atmosphere absoluteExperimentalParticipants in this group will be exposed to hyperbaric oxygen at 1.5 atmosphere absolute (ATA) for 60 minutes per session. Each participant will complete 40 sessions, five sessions per week within 3 months from randomization
Receives: Drug: Hyperbaric oxygen at 1.5 ATA
Sham control initially at 1.2 then changed to 1.0 ATASham comparatorParticipants in this group will be exposed to hyperbaric oxygen at 1.2 atmosphere absolute (ATA) during the first 5 to 7 minutes and the chamber pressure will be reduced to 1.0 ATA for the remaining 53 - 57 minutes for a total of 60 minutes per session. Each participant will complete 40 sessions, five sessions per week within 3 months from randomization
Receives: Drug: Sham treatment

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Changes in Repeatable Battery for the Assessment of Neuropsychological Status (RBANS)

    RBANS comprises 12 subtests that yield five age-adjusted Index scores, each measuring a distinct cognitive domain, plus a Total Scale score reflecting global cognitive functioning:

    Immediate Memory Index Visuospatial/Constructional Index Language Index Attention Index Delayed Memory Index Raw subtest scores are converted to age-normed standard scores, yielding five Index scores and a Total Scale score, each with a normative mean of 100, standard deviation of 15, and obtainable range of approximately 40 to 160. The Total Scale score is not a sum or average of the Index scores; the five Index scores are summed, and that sum is converted to a standard score on the same metric. For every Index and for the Total Scale score, higher values indicate better cognitive performance, and lower values indicate worse performance. All values reported are age-adjusted standard scores; the "3-12 Months" row is each participant's mean across the 13-week, 6-month, and 12-month assessments.

    Measured: 13-week, 6-month, 12-month

Secondary outcomes (5)

  1. Serum Concentrations of GFAP, NfL, Total Tau, and UCH-L1 at Baseline and 13 Weeks Post-Treatment

    Serum concentrations of glial fibrillary acidic protein (GFAP), neurofilament light chain (NfL), total tau, and ubiquitin C-terminal hydrolase L1 (UCH-L1), quantified in a single batch using the Quanterix Simoa Neurology 4-Plex B assay. Laboratory personnel were blinded to treatment allocation.

    Measured: Baseline, 13-week

  2. PSQI Global Score

    Description (components): Pittsburgh Sleep Quality Index component scores. Each of the seven components is scored 0-3; higher scores indicate worse sleep. C1 = subjective sleep quality; C2 = sleep latency; C3 = sleep duration; C4 = habitual sleep efficiency (hours slept ÷ hours in bed × 100); C5 = sleep disturbances; C6 = use of sleep medication; C7 = daytime dysfunction.

    Description (global): PSQI global score, the sum of all seven component scores. Range 0-21; higher scores indicate worse sleep quality. A global score >5 indicates poor sleep quality.

    Measured: Baseline, 13-week, 6-month, 12-month

  3. Neurobehavioral Symptom Inventory Total Score

    This is a validated self-report measure of post-concussion symptoms, grouped into 4 clusters (somatosensory, cognitive, affective, and vestibular). Neurobehavioral Symptom Inventory (NSI) is a 22-item symptom scale; participants will rate the severity of their symptoms in the last 2 weeks on a 5-point Likert scale (0=none, 1= mild, 2=moderate, 3=severe, 4=very severe). The NSI total score is a sum of the 22 items (range 0-88). Higher scores indicate more severe symptoms.

    Measured: Baseline, 13 week, 6 month, 12 month

  4. PCL-C Total Score c(Civilian)

    This is a 17-item validated self-report measure that assesses PTSD symptoms. It is further subcategorized into three clusters (reexperiencing, avoidance, hyperarousal). A total score and cluster scores can be obtained based on DSM-IV-TR criteria. Each item is rated 1-5; total score ranges 17 to 85. Higher scores indicate worse symptom burden.

    Measured: Baseline, 13 weeks, 6 months, 12 months

  5. WHOQOL-BREF Psychological Domain Score

    World Health Organization Quality of Life - BREF (WHOQOL-BREF), a 26-item self-report instrument yielding four domain scores. All four domain scores are transformed to a 0-100 scale. Higher scores indicate better quality of life. The psychological domain result is shown here.

    Measured: Baseline, 13 weeks, 6 months, 12 months

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted30 Dec 2021
  2. Study start28 Jun 2022
  3. Primary completion1 Aug 2025
  4. Study completion1 Aug 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 2
Primary purpose
Treatment
Allocation
Randomised
Intervention model
Parallel groups
Model description
Parallel Assignment
Masking
Double blind
Who is masked
Participant, Outcomes assessor
Enrolment
20 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05173818
Sponsor's protocol ID
EH21714
Acronym
HOINPCS
Status last verified
Sep 2026
First submitted
13 Dec 2021
Last updated
15 Oct 2026
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
Yes: The study protocol, statistical plan and consent form will be available on request. Data will be available on aggregate level; data will be deidentified, the full dataset and statistical code will be available upon request

Publications

  • Moser RS, Schatz P. Enduring effects of concussion in youth athletes. Arch Clin Neuropsychol. 2002 Jan;17(1):91-100.

    PubMed 14589756

  • Shahim P, Politis A, van der Merwe A, Moore B, Chou YY, Pham DL, Butman JA, Diaz-Arrastia R, Gill JM, Brody DL, Zetterberg H, Blennow K, Chan L. Neurofilament light as a biomarker in traumatic brain injury. Neurology. 2020 Aug 11;95(6):e610-e622. doi: 10.1212/WNL.0000000000009983. Epub 2020 Jul 8.

    PubMed 32641538

  • Cook PA, Johnson TM, Martin SG, Gehrman PR, Bhatnagar S, Gee JC. A Retrospective Study of Predictors of Return to Duty versus Medical Retirement in an Active Duty Military Population with Blast-Related Mild Traumatic Brain Injury. J Neurotrauma. 2018 Apr 15;35(8):991-1002. doi: 10.1089/neu.2017.5141. Epub 2018 Mar 1.

    PubMed 29239267

  • Weaver LK, Wilson SH, Lindblad AS, Churchill S, Deru K, Price RC, Williams CS, Orrison WW, Walker JM, Meehan A, Mirow S. Hyperbaric oxygen for post-concussive symptoms in United States military service members: a randomized clinical trial. Undersea Hyperb Med. 2018 Mar-Apr;45(2):129-156.

    PubMed 29734566

Questions about this trial

What is this clinical trial studying?

A Phase 2 study testing Hyperbaric oxygen at 1.5 ATA in people with Persistent Post-concussive Syndrome and Concussion Post Syndrome, run by Essentia Health at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 11 inclusion and 21 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 15 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 2 studies give the treatment to a larger group to see whether it has the intended effect and to keep checking safety.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 15 Oct 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Changes in Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) (time frame: 13-week, 6-month, 12-month). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05173818, which also lists 4 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 15 Oct 2026.

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