Why did the sham group also improve in the Collet study?

Researchers aren't certain. Slightly pressurized air may have some biological effect, or the intensive clinic environment and attention may have driven improvements. This finding makes it harder to determine whether HBOT specifically was responsible for any benefit.

How much does HBOT for cerebral palsy cost?

Typical protocols for CP run 40-60 sessions at $250-450 per session. Total out-of-pocket costs often fall between $10,000-27,000. Insurance will not cover HBOT for cerebral palsy.

Hyperbaric Oxygen Therapy for Cerebral Palsy: Mixed Evidence

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

Parents researching HBOT for a child with cerebral palsy deserve a straight answer about what the evidence shows. The answer is: mixed, and complicated by a study design issue that makes results hard to interpret.

Here’s the full picture.

What Cerebral Palsy Is

Cerebral palsy (CP) refers to a group of permanent movement disorders caused by damage to the developing brain — typically during pregnancy, birth, or in the first few years of life. CP is non-progressive, meaning the brain injury itself doesn’t worsen. But the physical and functional effects can change as children grow.

CP affects muscle tone, movement, and motor skills. Severity ranges widely. Some children with CP walk independently. Others need assistive devices or full-time care. Many have associated conditions — epilepsy, intellectual disability, vision or hearing problems, communication challenges.

Standard care focuses on maximizing function. Physical therapy, occupational therapy, and speech therapy form the core of most treatment plans. Medications and surgeries address specific symptoms like spasticity.

The Landmark Study — and What Made It Complicated

Collet et al. (2001) is the most rigorous study on HBOT for CP. Published in Developmental Medicine and Child Neurology, it enrolled 111 children in a double-blind randomized controlled trial. PMID: 11305401.

Children were assigned to one of two groups: standard HBOT at 1.75 ATA with 100% oxygen, or a sham protocol using slightly pressurized air at 1.3 ATA. The sham was designed to feel like real treatment — the pressure sensation, the chamber, the sessions.

Both groups improved on functional measures. The HBOT group improved. The sham group also improved. The difference between the two groups was not statistically significant.

This is an important finding. If HBOT specifically were driving the improvements, you’d expect the HBOT group to improve significantly more than the sham group. That didn’t happen.

What explains the sham group’s improvement? Researchers aren’t certain. One possibility: slightly pressurized air at 1.3 ATA has some biological effect of its own. Another: the intensive clinic environment — consistent attendance, structured sessions, parent engagement — drove improvements through attention and activity, regardless of the treatment itself.

The Collet study is honest about this. Both groups improved, and the study couldn’t tell us whether HBOT deserves the credit.

A Second Study With Different Results

Marois et al. (2006) took a different approach. This study of 33 children compared HBOT against standard care — not a sham protocol. The HBOT group showed functional improvements. PMID: 16420028.

This result seems more favorable for HBOT, but the study is smaller and the comparison group matters. Standard care without the intensive clinic environment may put the control group at a disadvantage compared to the Collet sham, which still got the clinic visits and attention.

Neither study resolves the question definitively.

Why the Cost Is a Real Factor

A typical HBOT protocol for CP involves 40-60 sessions. At $250-450 per session, total costs fall between $10,000-27,000, all out of pocket. Insurance won’t cover it.

For families already managing the costs of therapies, equipment, and medical care for a child with CP, that’s a significant financial commitment for uncertain results. The Collet study — the strongest evidence we have — found no significant difference between HBOT and pressurized air.

That’s not a reason to dismiss the treatment entirely. It is a reason to weigh the cost against the evidence honestly before committing.

How HBOT Is Proposed to Work

The biological rationale for HBOT in CP centers on the concept of perilesional tissue. Near the site of a brain injury, some neurons may still be alive but not functioning — sometimes called “idling neurons.” The theory is that improved oxygen delivery could reactivate some of that tissue.

HBOT may also support angiogenesis — the growth of new blood vessels — in and around the affected brain tissue. Better blood supply means better oxygen delivery and potentially improved function.

These are plausible mechanisms. The Collet study’s results, though, make it hard to know how much they actually contribute in practice.

What Standard Care Provides

Physical therapy, occupational therapy, and speech therapy have decades of evidence behind them for CP. Constraint-induced movement therapy, aquatic therapy, and other specialized approaches have been studied specifically in CP populations.

Botulinum toxin injections reduce spasticity in specific muscle groups. Selective dorsal rhizotomy (SDR) can reduce spasticity more broadly for carefully selected children. Intrathecal baclofen pumps address severe spasticity.

HBOT doesn’t replace any of these. Your child’s care team — which ideally includes a developmental pediatrician, pediatric neurologist, and therapists — can evaluate whether adding HBOT makes sense alongside standard care, not instead of it.

FAQ

Is HBOT FDA-approved for cerebral palsy? No. It’s investigational. Insurance won’t cover it.

What did the Collet 2001 study find? Both the HBOT group and the sham group improved. The difference wasn’t statistically significant. PMID: 11305401.

Why did the sham group also improve? Unclear. Possibly a mild effect from slightly pressurized air, or the clinic environment itself drove improvements.

How much does it cost? $10,000-27,000 out of pocket for a 40-60 session protocol. Insurance won’t cover it.

Should HBOT replace standard CP therapies? No. PT, OT, and speech therapy are the established treatments. Ask your care team about HBOT as a possible addition, not a replacement.

References

Collet et al. (2001). Hyperbaric oxygen for children with cerebral palsy: a randomised multicentre trial. Developmental Medicine and Child Neurology. PMID: 11305401
Marois et al. (2006). Hyperbaric oxygen therapy and cerebral palsy. PMID: 16420028

Medical Disclaimer: This page is for informational purposes only. It does not constitute medical advice. Hyperbaric oxygen therapy for cerebral palsy is investigational and not FDA-approved. Consult your child’s care team before making any treatment decisions. Individual outcomes vary. This site does not establish a doctor-patient relationship.