ARI Publication 40 – 2013 Version

Hyperbaric Oxygen Therapy (HBOT)

Rationale: There is substantial evidence of decreased blood flow in brains of most children with
autism, suggesting a need for more oxygen. HBOT is an effective method to temporarily increase
oxygen levels throughout the body. It is effective for improving general wound healing, and might
help with gut inflammation, brain inflammation, and similar problems that are common in children
with autism.

Treatment: Typically 40 1-hour sessions, 1-2x/day, in a chamber with 30% increased air pressure
(1.3 atm), which temporarily increases level of oxygen in the body. A face mask with pure oxygen
is sometimes used as well (regular air is only 22% oxygen). Higher pressures of 1.5-2 atm are
sometimes used, but there is concern regarding excessive oxidative stress at higher partial
pressures. Additional treatment hours are sometimes considered if the initial therapy is beneficial.

Testing: Currently it is unclear what tests may indicate who is the best candidate for HBOT.
One small study of 18 children with autism found that HBOT therapy was able to substantially
reduce levels of C-Reactive Protein (CRP, a marker of inflammation), primarily in the 3 children with
elevated levels. So, this might be a useful biomarker, but more research is needed.

Rossignol DA, et al., The effects ofhyperbaric oxygen therapy on oxidative stress, inflammation, and
symptoms in children with autism: an open-labelpilot study. BMC Pediatr 2007, 7:36.

Safety Concerns:

1) Glutathione: One small study found that HBOT therapy decreased levels of plasma glutathione,
which are already low in children with autism, so it is recommended to first normalize glutathione
prior to starting HBOT. This is consistent with the notion that HBOT can increase reactive oxygen
species, especially at higher partial pressure.

Rossignol DA, et al., The effects ofhyperbaric oxygen therapy on oxidative stress, inflammation, and
symptoms in children with autism: an open-labelpilot study. BMC Pediatr 2007, 7:36.

2) Primary Mitochondrial Disease: A small percent of children with autism also have primary
mitochondrial disease. According to an expert on mitochondrial disease, Robert Naviaux, MD, PhD:
“Hyperbaric oxygen therapy is contraindicated in children with primary mitochondrial disease and
has led to serious injury and death in some patients. Primary mitochondrial disease is characterized
by gene defects that make cells unable to use oxygen to produce energy. Forced exposure to high
levels of oxygen under these circumstances, when the cells cannot use oxygen, can result in large
increases in oxygen free radical production, tissue oxidative damage, and no neurologic or
metabolic benefit… The Scientific Advisory Board of the United Mitochondrial Disease Foundation
(UMDF) addressed this issue in 2007, and this expert opinion was published in Mitochondrial News
12: 1 and 20, 2007.”

3) Seizures: There have been some anecdotal reports of seizure onset following HBOT, but this
has not been confirmed in a published study. A published parent survey of the effect of different
treatments on individuals with autism and seizures included a small sample of 36 people who had
tried HBOT. The survey found that HBOT possibly had a small beneficial effect on reducing
seizures, a very low rate of adverse effects, and possible improvements in several areas, primarily
communication.

Frye RE, et al., Traditional and non-traditional treatments for autism spectrum disorder with seizures:
an on-line survey, BMC Pediatrics 2011, 11:37.

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