Several anecdotal reports suggest that hyperbaric oxygen therapy, in which children are placed in a pressure chamber with above-normal levels of oxygen, can improve the behavior of children with autism, and many parents have begun subjecting their autistic children to such treatments, even though it is expensive and not covered by insurance. Physicians, moreover, do not see a biological rationale for why the therapy should work, although some suggest providing extra oxygen to the brain might be responsible for the perceived benefits.
Now Florida researchers have conducted the first controlled trial of the therapy and, although the trial was small, they also found beneficial effects.
Dr. Daniel A. Rossignol of the International Child Development Resource Center in Melbourne, Fla., and his colleagues enrolled 62 children, ages 2 to 7, at eight U.S. centers. Over the course of a month, half of the children received 40 one-hour treatments in which they were placed in a chamber containing 24% oxygen at 1.3 atmospheres pressure. The control group received 40 treatments in a room containing 21% oxygen at 1.03 atmospheres.
The team reported Saturday in the journal BMC Pediatrics that the children in the treatment group had significant improvements in overall function, language receptiveness, social interaction, eye contact and sensory awareness. The results were most pronounced in the children over the age of 5 and in those with milder cases of autism, they said.
"We're not saying it's a cure, but ... if you can improve understanding so a kid doesn't run in front of a car, or improve sleep, that would be a benefit," Rossignol told Scientific American.
Side effects included bruised eardrums and claustrophobia.
Commercial hyperbaric chambers are typically used for treating the bends, resulting from ascending from a dive too fast, and carbon monoxide poisoning. Treatments typically cost $120 to $150 per session. Some parents have bought home units to treat their children between commercial sessions, and some experts estimate that as many as 10% of autistic children in the United States are now receiving the therapy.
Because only 31 children actually received treatment during the study, it clearly needs to be replicated in larger numbers. Researchers also need to determine how long the purported benefits persist. Critics also note that Rossignal is one of the biggest promoters of hyperbaric oxygen therapy for autistic children and has staked his career on obtaining positive results. The study was funded by manufacturers of the devices, who also have a vested interest.
--Thomas. H. Maugh II