HONOLULU -- Kalma Wong has tried almost everything for her two autistic children: special diets, intense behavioral therapies, flying in experts from the U.S. mainland at exorbitant costs.
Some efforts have yielded modest success. Others have done next to nothing.
But like other parents of the more than 1.5 million autistic children in the U.S., Wong has vowed to keep trying until she pinpoints the treatment that most helps her kids.
Her latest attempt is one of the most long-shot therapies yet, a protocol some doctors praise but that others call a waste of time that gives desperate parents false hope and exploits them financially.
It is called hyperbaric oxygen therapy, a treatment in which pure oxygen is delivered to patients confined to pressurized chambers for an hour a day for several weeks.
The theory is that extreme doses of oxygen under pressure - used for decades to cure divers with decompression illness - will spur dormant or damaged neurons in the brain to become reinvigorated or even transformed.
In the case of children with autism, considered the fastest-growing developmental disability in the U.S. today, advocates claim some stunning results: transforming nonverbal children into fluent speakers; helping children hypersensitive to outside stimuli become calm enough to attend public schools; changing kids once adverse to any personal interaction or touching into affectionate toddlers.
"I don't know what to expect from this," Wong said, "but the minute I heard about the upcoming trial, I called and got my kids on the list. I feel like it's worth a shot."
Her reaction is just what some autism experts fear.
"I understand that what all parents want is to be able to look back and say they did everything they possibly could to help their child," said Dr. Tina Iyama, professor of pediatrics at the University of Wisconsin-Madison and an expert on autism. "That's why they are trying all these experimental new treatments. But ... there is absolutely no reason to think that improving oxygen levels in a child with autism will be helpful."
The debate over hyperbaric oxygen therapy, or HBOT, well illustrates the fault lines over autism, a disorder that affects up to 1 out 150 children, according to the Centers for Disease Control and Prevention. Because there is no medical consensus on what causes autism, there also is little agreement on how best to treat it.
Some doctors believe that the components of childhood vaccines, such as mercury-based preservatives, are responsible for many cases of autism. They advocate detoxification programs in which children take chemicals that bind with metals in the body and force them out through urine.
Others promote gluten-free diets under the theory that autistic children have high levels of a certain type of yeast in their digestive tracts.
And then there are the proponents of HBOT, which has gained a following among parents who claim it has helped children with neurological problems, including cerebral palsy, traumatic brain injury, encephalitis and, most recently, autism.
Inside an office in an industrial section of Honolulu is the Hyperbaric Medicine Center. The first stop on the tour by Dr. Maryellen Markley, the facility's patient care coordinator, is in front of two color brain scans that she said show the profound results of HBOT.
The first scan, she says, reveals that the autistic child scanned had decreased blood flow and profound neuroinflamation before the oxygen therapy.
"Look at how much has changed in the second scan," Markley said, pointing. "Better blood flow, less inflammation, more connections between the two sides of the brain. This child, a 6-year-old, was completely nonverbal since the age of 1 1/2 , and after 66 hours of hyperbaric oxygen therapy was talking again."
Markley said she has treated more than 30 autistic children with HBOT and "every single child of those 33 had consistent quality-of-life improvements." The improvements, she said, were more pronounced in kids most afflicted by the characteristics of autism: the repetitive behaviors and the impairments in sensory perception, social interaction and communication.
Critics argue that there have been no studies of HBOT and autism that use rigorous scientific models such as double-blind testing. The only evidence involves a handful of autistic youngsters, not nearly enough to draw statistical conclusions.
"There is no evidence in any brain problem that a hyperbaric chamber helps," said Dr. Gary W. Goldstein, president and CEO of the Kennedy Krieger Institute in Baltimore, which specializes in children's developmental problems.
"Here there is no scientific rationale, and there's actually a school of thought developing that ... breathing in too much oxygen can actually damage brain tissue."
Evidence is exactly what supporters of HBOT are hoping to get in the coming months. Beginning in May, the Honolulu clinic joins 20 other hyperbaric oxygen centers across the U.S. in a formal study of 400 children to determine how they respond to the therapy.
Among other relevant HBOT studies now under way is one involving children with cerebral palsy at Wright-Patterson Air Force Base in Dayton, Ohio.
Among the skeptics is the Undersea and Hyperbaric Medicine Society, a nonprofit group of doctors that investigates scientific claims linked to HBOT. Thus far the group has been wary of using HBOT to treat neurological conditions such as autism or cerebral palsy.
"If we just had the evidence, we'd be happy to support it. But it just isn't there," Dr. Donald Chandler, director of the UHMS, has said in statements regarding the therapy.
In many other medical situations, HBOT is widely accepted. It is a well-documented treatment for slow-healing wounds, bad burns, carbon monoxide poisoning, intracranial abscesses, gangrene and the stubborn sores associated with diabetes. Many insurance companies include HBOT in their list of reimbursable medical expenses for these conditions.
Supporters of HBOT treatments for neurological conditions cite one case in Georgia where a state judge ordered the local Medicaid program to pay for HBOT treatments that greatly improved the condition of a child with cerebral palsy.
The treatment is far from cheap - from $180 to $800 per hour.
Even its critics don't generally argue that the therapy is dangerous. Although they cite a remote risk of seizures, most say HBOT is simply a waste of time and money.
"My fear is that we're going to waste tax dollars and good time and money chasing quirky ideas," said Iyama, who heads an autism clinic in Madison, Wis. "The only effective treatment for autism is educational and behavioral treatment. The rest is just wishful thinking."
Major medical groups share this sentiment. The American Academy of Pediatrics issued a statement several years ago dismissing most alternative-medicine treatments for autism.
Iyama worries that parents frustrated by their children's condition will make bad decisions about experimental therapies. She stressed that the most accepted treatment for autism is intensive behavior therapy and warned that some parents are drawn to treatments that promise faster results.
Wong, whose two children will begin HBOT in May, is not putting her hopes on any one thing. She continues to immerse her children in behavioral therapies, to work with national autism educational experts and adhere to a rigorous gluten-free diet.
"The bottom line," Wong said, "is that when you are the parent of an autistic child, you learn to appreciate the treatments that yield even subtle changes."
Kirsten Scharnberg writes for the Chicago Tribune. Sun reporter Chris Emery contributed to this article.