Skip to content
hyperbaric.app
brain injuryTBIconcussionstrokeresearch

Hyperbaric Oxygen for TBI, Concussion and Stroke: What Studies Show

Can hyperbaric oxygen help TBI, post-concussion syndrome or stroke? What Israeli trials, US military sham-controlled trials and Cochrane reviews found.

Updated September 14, 2026
12 min read
by Hyperbaric.app

This content is for informational purposes only and does not constitute medical advice. Always consult a healthcare professional. Read full disclaimer

Hyperbaric oxygen therapy (HBOT) for traumatic brain injury (TBI), post-concussion syndrome and stroke is still investigational. Israeli and US trials have reported improvements in thinking and quality of life, but four US military trials that used a sham chamber session found either no significant benefit over sham or benefits that faded within months. For acute ischaemic stroke, a Cochrane review found no good evidence of benefit, and European hyperbaric specialists recommend against HBOT in the acute phase.

Brain-related conditions where HBOT is an accepted treatment include carbon monoxide poisoning, arterial gas embolism and intracranial abscess. This article covers the conditions where it is not yet accepted.

Is HBOT an Accepted Treatment for Brain Injury or Stroke?

ConditionECHM 2016 recommendationUHMS and Medicare
Acute moderate to severe TBIType 3 (optional), in highly selected patients; to be used only within ethics-approved researchNot a UHMS indication; Medicare does not cover acute cerebral oedema
Chronic TBI, including post-concussion syndromeType 3 (optional), only in highly selected patients with clear evidence of metabolically dysfunctional brain regions, within researchUHMS: investigational; not on Medicare's covered list
Acute strokeRecommended against (Type 1, Level C)Not a UHMS indication; Medicare does not cover acute or chronic cerebral vascular insufficiency
Chronic strokeType 3, Level C, only within an investigational study in highly selected patientsNot a UHMS indication; Medicare does not cover chronic cerebral vascular insufficiency

The European Committee for Hyperbaric Medicine (ECHM) specifically recommends that HBOT for TBI be used "only in the context of an investigational study protocol approved by an ethics committee". The Undersea and Hyperbaric Medical Society (UHMS) notes that HBOT for TBI has been studied in several randomised trials and is "at this time considered investigational". Medicare's list of non-covered conditions also includes Alzheimer's disease and senility. Our guide to accepted HBOT indications lists the conditions that are covered.

HBOT for Post-Concussion Syndrome and Mild TBI

Most people recover from a concussion, but a 2022 review by Harch estimates that over 15% of people with mild TBI develop persistent post-concussion syndrome, with lasting problems that trials have measured in memory, concentration, mood and sleep. This is where most recent HBOT research has focused, and where the results conflict most.

Trials reporting benefit

TrialPatientsTreatment and comparisonResult
Boussi-Gross 2013, Israel (PLOS ONE)56 patients, 1 to 5 years after mild TBI40 sessions, 60 minutes at 1.5 ATA, versus a 2-month no-treatment period followed by crossoverCognitive function and quality of life improved after HBOT but not during the control period; SPECT scans showed increased brain activity
Harch 2020, USA (Medical Gas Research)63 civilian and military participants (50 completed)40 sessions, 60 minutes at 1.5 ATA, versus no treatment followed by crossoverImprovements in symptoms, memory, cognition, depression, anxiety, sleep and quality of life, persisting at least 2 months
Hadanny 2022, Israel (Scientific Reports)25 children aged 8 to 15, 6 months to 10 years after injury60 daily sessions of HBOT versus sham, double-blindImproved cognitive scores, post-concussion symptoms and behaviour

The first two trials compared HBOT with no treatment, so patients knew whether they were being treated. That design cannot separate the effect of oxygen from expectation and the attention of daily sessions. The paediatric trial used a sham, but it was small, with 25 children.

US military sham-controlled trials

The US Department of Defense and partners ran several blinded trials in service members with persistent symptoms after mild TBI:

  • Wolf 2012 (US Air Force). 50 service members received 30 sessions at 2.4 ATA or a sham of room air at 1.3 ATA. Both groups improved, with no significant difference between them.
  • Cifu 2014 (US Navy). 60 service members had 40 chamber sessions at 2.0 ATA, breathing gas mixes that gave an oxygen dose equivalent to surface air, 100% oxygen at 1.5 ATA, or 100% oxygen at 2.0 ATA. There was no significant benefit of either oxygen dose over sham.
  • HOPPS, Miller 2015 (JAMA Internal Medicine). 72 service members were randomised to 40 sessions at 1.5 ATA, 40 sham sessions of air at 1.2 ATA, or usual care only. HBOT showed no benefit over sham. Both chamber groups improved more than usual care, which the authors said suggests the improvements were "not oxygen mediated" and may reflect placebo effects.
  • BIMA, Weaver 2018 (Undersea and Hyperbaric Medicine). 71 participants received 40 sessions at 1.5 ATA or sham at 1.2 ATA. The HBOT group had better symptom scores at 13 weeks, especially those with PTSD, but the improvements regressed at 6 and 12 months. In extended follow-up there were no group differences at 24 or 36 months.

The debate over "sham" sessions

Supporters of HBOT argue that these sham sessions were not truly inactive. In a 2022 dose analysis, Harch reported that symptoms improved in one study at 1.3 ATA air, that results at 1.2 ATA air were mixed, and that 40 sessions at 1.5 ATA oxygen produced significant improvements in symptoms or cognition in four randomised trials. He argued pressure itself may be the more important ingredient. Harch declares co-ownership of a hyperbaric service and consulting company, and all included studies had fewer than 75 participants.

What the systematic reviews say

A 2026 meta-analysis (Wang and colleagues) pooled 8 randomised trials with 570 adults, most with mild TBI. HBOT improved computerised cognitive test scores, executive function and processing speed, memory and sleep quality. It found no significant benefit for neurobehavioural symptoms, PTSD symptoms or emotional distress, and noted the evidence says little about moderate to severe TBI.

For acute TBI treated in intensive care, a 2012 Cochrane review (Bennett and colleagues) of 7 trials with 571 people found HBOT may reduce the risk of death, but there was little evidence that survivors had good outcomes. The authors concluded routine use "cannot be justified" and called the trials small and at significant risk of bias.

Hyperbaric Stroke Therapy

Acute stroke

A stroke is a medical emergency. If you think someone is having a stroke, call your local emergency number immediately; HBOT is not an emergency stroke treatment.

The 2014 Cochrane review of HBOT for acute ischaemic stroke (Bennett and colleagues) included 11 randomised trials with 705 participants. It found "no good evidence to show that HBOT improves clinical outcomes" when used during acute presentation, although benefit was not ruled out. The ECHM recommends against HBOT in the acute phase of stroke.

Months or years after a stroke

  • Efrati 2013, Israel (PLOS ONE). 74 patients enrolled (15 excluded) who had a stroke 6 to 36 months earlier and at least one motor problem. Patients had 40 sessions of 90 minutes at 2 ATA, either straight away or after a 2-month no-treatment period. Neurological function and quality of life improved after HBOT but not during the control period, and SPECT imaging changes matched the clinical gains. There was no sham group.
  • Harrison 2024, Canada (Cureus). This single-centre trial in Vancouver compared 40 HBOT sessions with sham, later switching to a waitlist control to boost recruitment. It planned 68 participants per group but stopped after enrolling 34. At the end of treatment the stroke impact score was 5.5 points better in the sham group, and the authors wrote that their results "do not support the use of HBOT in chronic stroke survivors."

Both trials are small, and they point in opposite directions. The ECHM had already limited HBOT for chronic stroke to research settings in 2016.

Healthy Ageing and Cognitive Decline

A 2020 Israeli trial (Hadanny and colleagues) randomised 63 healthy adults over 64 to three months of HBOT or a no-intervention control group. The HBOT group improved on global cognitive function, particularly attention and information processing speed, and MRI showed increased blood flow in several brain regions. There was no sham procedure and participants knew their group, so expectation effects cannot be excluded, and the study measured test performance rather than dementia prevention. The FDA's consumer guidance stated that HBOT is not proven to cure Alzheimer's disease.

Why Do the Results Differ?

  • Control groups. Trials using no-treatment controls tend to report benefit; several sham-controlled trials did not. The HOPPS trial showed that people improve after chamber sessions even without extra oxygen.
  • Dose. Trials used 1.5, 2.0 or 2.4 ATA, and researchers disagree about whether low-pressure air is a true placebo.
  • Patient selection. The ECHM suggests only patients with imaging evidence of dysfunctional but living brain tissue might benefit.
  • Durability. In BIMA, early gains had faded by six months.
  • Size. Every trial described here had fewer than 100 participants.

Is HBOT Safe for People With Brain Injury?

In a review of 62,614 sessions in 2,334 patients at an Israeli centre (Hadanny 2016), seizures occurred in 1 of every 8,945 sessions and only one was clearly caused by oxygen toxicity. The authors concluded HBOT can be considered safe for people with chronic neurological conditions, except uncontrolled epilepsy. Ear barotrauma and temporary short-sightedness are the most common side effects; see our HBOT side effects guide.

Questions to Ask Before Trying HBOT for a Brain Condition

  1. Is this investigational for my condition, and is it offered within a registered, ethics-approved study?
  2. What pressure, oxygen level and chamber will be used? Medical HBOT uses hard-shell chambers at 2.0 ATA or more with medical-grade oxygen, while the brain trials mostly used 1.5 to 2.0 ATA. Compare chamber types in our hard-shell vs soft-shell guide.
  3. How were patients like me selected in the trials you are relying on, and were there sham controls?
  4. How will progress be measured, and what happens if there is no improvement after a set number of sessions?
  5. Will my rehabilitation continue alongside, and who coordinates with my neurologist?
  6. What will it cost? Medicare does not list these conditions as covered, so check with your insurer; see our guide to HBOT insurance coverage.

Our checklist on how to choose an HBOT clinic covers accreditation and staff training.

Sources

This article is for information only and is not medical advice. HBOT for brain injury, concussion and stroke is investigational. Decisions should be made with your neurologist and a qualified hyperbaric physician.

Back to all articles