Hyperbaric Autism Treatment Shows Possible Promise

Researchers say hyperbaric chamber treatment merits further study.

March 12, 2009, 6:13 PM

March 13, 2009— -- To battle her son's autism, Kazuko Curtin did more than look into a treatment -- she started a clinic for it.

Twelve years ago, Curtin was told by doctors that her son had autism. In subsequent years, while attending conferences, she heard about treatment in a hyperbaric chamber, where pressure is increased in an attempt to boost the amount of oxygen in the child's brain.

Curtin bought a machine, and today a hyperbaric chamber is one of the treatments offered by the CARE Clinics in Austin, Texas, and Tampa, Fla., which she opened last year.

"Hyperbaric is very useful," said Curtin. "You never think autistic children are going to stay inside the hyperbaric for 90 minutes, because they are very restless. What's amazing -- they like it! For some reason, they are very calm inside."

Curtin is the not the first to use hyperbaric therapy, a procedure with little scientific backing for the treatment of autism. But a new, small study of 56 children treated at several small clinics may change that if the findings can be replicated.

"We wanted to do a formal study that looked to see if this was even a valid treatment," said Dr. Daniel A. Rossignol of the International Child Development Resource Center in Melbourne, Fla., and the study's lead author. "We hoped to stimulate more research."

Several experts contacted by ABC News for this story refused to speak on the record about hyperbaric therapy. And others who did speak on the record harbored some skepticism.

"I am concerned that the data don't support the authors' conclusions," said Dr. Max Wiznitzer, a pediatric neurologist at the Rainbow Babies and Children's Hospital in Cleveland.

Still, perhaps because the therapy, while still unproved as a remedy, does not appear to physically harm a child, this study may draw less controversy than many autism studies have in the past.

Rossignol and the study's other physicians offer therapy in a hyperbaric chamber in their own practices -- a potential conflict of interest that they noted in their paper. They said that this means that results will need to be replicated before the therapy can be recommended.

"Obviously, we need other people who've studied this as well," he said.

Rossignol said he was first introduced to the therapy when his wife wished to use it in an attempt to treat their own two children, who have autism.

For the study, researchers looked at 56 children ages 2 to 7 who had varying degrees of autism. Each received 40 treatments of an hour each.

Thirty of the children had the pressure in the chamber increased by 30 percent, while the 26 children in the control group had the pressure increased by 3 percent.

In the end, researchers reported that 30 percent of the children who received the treatment reported greatly increased functioning, while 8 percent in the control group did.

Despite an influx of research dollars in recent years, autism research has yet to yield either the cause of autism or a cure. And the lengthy path from finding a cause to using that information on a cure has left many parents frustrated.

That, in turn, has led to the use of a number of therapies considered risky, including chelation, the removal of heavy metals from the body.

But while its positive effects remain unclear, hyperbaric chamber therapy does not present the dangers that other therapies do.

"I think the biggest drain would be a financial drain," said Dr. Paul Offit, chief of the section on infectious disease at the Children's Hospital of Philadelphia and author of "Autism's False Prophets," a book that chronicles some of the dangerous treatments parents of autistic children have tried.

Offit noted that parents of autistic children have been known to take out second mortgages in order to buy hyperbaric chambers, so the therapy, which remains unproved, presents a risk to a family's financial health.

"One should make certain that you get it right," he said.

Dr. L. Eugene Arnold, interim director of the Nisonger Center for developmental disabilities at Ohio State University, echoed those sentiments.

He said that because of the "expense and difficulty of 40 treatments in a hyperbaric chamber [it will] require more evidence before it could be recommended as a standard treatment."

Recent news accounts have placed the cost of hyperbaric treatment at $100 to $900 per treatment at a center. Children in the recent study received 40 treatments.

While he remains skeptical, Offit said the treatment does merit further research.

"It would be of value for the study to be repeated by an academic group that doesn't have a financial desire to see it work," he said. "I think it's good, certainly, that there was an attempt to do this study in a prospective, placebo-controlled way."

Offit also said, however, that some changes would need to be made in a future study, as certain factors may have biased the results of this one. The main problem he cited was observer bias; since parents were sometimes present in the hyperbaric chamber with their children, they were likely aware of whether or not their children received increased pressure, and this may have affected their impression of their child's progress.

"I just think it was a lost opportunity," said Offit. "I don't think it really matters who funds the study. What matters is the strength of the data."

Another problem some doctors had with the study was the theory behind why, exactly, treatment in a bariatric chamber might help. Since the cause of autism remains unknown, there are doubts whether any one specific therapy could help.

Researchers speculate in the paper that the oxygen flow to the brain is reduced in autistic children, a condition known as cerebral hypoperfusion, and the hyperbaric chamber is able to reverse that.

"This is purely speculative and not really supported by the references they cite. The authors appear to be 'stretching' the contents of the references beyond the original intent," Wiznitzer said.

Offit added that he, too, is skeptical of that idea because autism has been shown to affect specific areas of the brain, but if cerebral hypoperfusion was the problem it should be affecting the entire brain rather than specific regions.

Ultimately, more study will be needed to make any recommendations on hyperbaric therapy for autism. In the meantime, any parents seeking to try it may not have to worry about its effect on their child's health but will need to worry about their finances.

"This treatment has no apparent negative effects except for the cost [of out-of-pocket payments]," said Wiznitzer. "I tell parents that use of complementary and alternative treatments can be explored as long as there is no significant risk of injury, it does not interfere with other interventions, it is affordable and it has a defined endpoint."

Offit urged parents to be cautious.

"The way we work in this country ... when a paper comes out, we tend to take it as fact," he said. "We should wait until we see if this is reproduced."

Rossignol agreed that further study is needed.

"This is not a cure for autism or anything like that," he said. "It may be an adjunct and be helpful, but it's certainly not going to cure anybody."

ABC News' Michelle Schlief contributed to this report.