Hyperbaric Oxygen Therapy After Stroke: What the Evidence Shows

Important: Hyperbaric oxygen therapy is not FDA-approved for stroke recovery. This is an investigational use. Evidence is preliminary. Insurance will not cover HBOT for this condition. All costs are out-of-pocket.

Real research exists on HBOT after stroke, and one randomized controlled trial showed measurable neurological improvements. But it’s not FDA-approved and insurance won’t cover it. Here’s what the evidence actually says.

If someone is having a stroke right now, call 911. Do not look for alternative treatments. Time is brain.

HBOT and Stroke Recovery: The Theory

In an ischemic stroke, a blood clot blocks a brain artery and cuts off oxygen to part of the brain. The tissue at the center of that blockage dies quickly. But immediately surrounding it is an area called the ischemic penumbra, where neurons are damaged but potentially still recoverable.

The hypothesis for using HBOT is that delivering highly concentrated oxygen to the penumbra may rescue those neurons before they die permanently. HBOT can push oxygen directly into plasma, reaching tissues even when blood vessel circulation is impaired.

In chronic stroke, months or years later, a different theory applies. Some neurons may be dormant rather than dead, and HBOT may reactivate them by improving oxygen delivery and stimulating neuroplasticity.

This is important to say clearly: for acute stroke in the first hours, tPA (a clot-dissolving drug) and mechanical thrombectomy are the treatments with strong evidence. HBOT is not part of acute stroke emergency care and shouldn’t be considered in that context.

What the Research Has Found

Efrati et al. (2013) published a landmark study in PLOS ONE of 74 chronic ischemic stroke patients who were 6 months to 3 years post-stroke. Patients received 40 HBOT sessions or a control treatment. The HBOT group showed statistically significant improvements in neurological function compared to controls, including physical and cognitive measures (PMID: 23383003).

A follow-up analysis from the same research team confirmed that some of those improvements correlated with increased brain activity on SPECT imaging. That’s objective data, not just self-reported symptoms.

These findings are meaningful. But they come from a single center, and large multicenter trials haven’t yet replicated them. The scientific community is appropriately cautious about drawing firm conclusions from one study, however well-designed.

Who Is Being Studied

Most stroke-related HBOT research focuses on subacute and chronic stroke, meaning patients who are past the acute phase. Researchers are primarily studying ischemic stroke (clot-based), not hemorrhagic stroke (bleeding).

Research populations have included patients from 1 month to several years post-stroke. It’s not yet clear which window produces the best results, or which patients are most likely to respond.

What HBOT Won’t Replace

Standard stroke rehabilitation is the backbone of stroke recovery. Physical therapy, occupational therapy, and speech therapy have strong evidence behind them. HBOT shouldn’t replace any of those.

Insurance won’t cover HBOT for stroke recovery. At $250-450 per session, a 40-session protocol costs $10,000-18,000 out-of-pocket. Your care team can help you weigh whether that cost is reasonable given your situation and the current evidence.

Ask your neurologist or rehabilitation physician before pursuing HBOT. They can review the Efrati et al. findings with you in the context of your specific case.

Frequently Asked Questions

Will insurance cover HBOT for stroke? No. HBOT isn’t FDA-approved for stroke, and insurance won’t cover it. All costs are out-of-pocket.

Is HBOT safe after a stroke? HBOT is generally considered safe when performed in an accredited facility by trained staff. But it isn’t appropriate for everyone. Your neurologist needs to evaluate your specific medical history before you pursue it.

How soon after a stroke can HBOT be tried? The main trial studied patients 6 months to 3 years post-stroke. Earlier or later use hasn’t been studied as thoroughly. Ask your care team about timing.

Can HBOT help with hemorrhagic stroke? Most research has focused on ischemic stroke. The evidence for hemorrhagic stroke is much thinner. Don’t assume findings from ischemic stroke research transfer to hemorrhagic stroke.

References

Efrati, S. et al. (2013). Hyperbaric oxygen induces late neuroplasticity in post stroke patients — randomized, prospective trial. PLOS ONE. PMID: 23383003. https://pubmed.ncbi.nlm.nih.gov/23383003/

Browse all conditions on the conditions hub. For another brain-related investigational use, see the TBI and concussion page. The what is HBOT guide covers how sessions work, and the cost guide breaks down what clinics charge.

Medical Disclaimer: This page is for informational purposes only. It does not constitute medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before pursuing any medical treatment.