Tuesday, May 27, 2008

UW researchers seek better clues to autism

When her toddler son seemed not to notice a door slamming nearby during his checkup, Jo James thought nothing of it. Her husband, a Microsoft manager, also has an uncanny ability to block out his surroundings.

A check of Ben's hearing after a nurse's prompt found nothing amiss. It wasn't until two years and one perceptive Montessori teacher later that his parents finally learned the cause of Ben's obliviousness: autism.

"He didn't mix terribly well socially," Jo James, of Sammamish, recalled ruefully. "But then, what 2- 1/2-year-old boy does?"

Autism typically isn't diagnosed until after age 2. Yet it may be detectable even in infancy before a baby is old enough to display telltale traits such as social ineptitude and compulsive preoccupations. Pioneering research at the University of Washington during the 1990s, for example, found that trained observers can spot, with remarkable accuracy, kids who were later diagnosed with autism by viewing videos of their first birthdays.

Now UW researchers are aiming to decipher those early clues in hopes of short-circuiting autism before it becomes full-blown.

In January, they began a $11.3 million trial to identify latent signs of autism in infants for intensive behavioral therapy. It is the nation's first attempt to test a hypothesis that early intervention may actually prevent autism in high-risk infants by rewiring their brains.

"We know the brain has a lot of potential to respond" to the right stimulation, said Sara Webb, a research assistant professor of psychiatry and behavioral sciences and the principal investigator for the study at UW Autism Center.

The goal is "to teach parents to give the child that missing piece that he's not getting on his own."

The study's very premise that autism may need not be destiny has stirred unease and skepticism among some parents. They also fret that it may rekindle the discredited notion that autism is triggered by detached and unloving mothers.

"I object to the message that if parents don't rush out like headless chickens before the child is X age, they've lost them," said Lisa Rudy, a mother and autism advocate from Falmouth, Mass.

The implication is that "if only the mother spent more time bonding with the infant, that child will never develop autism," Rudy added.

But UW researchers say they're not laying any blame on parenting. The goal is akin to averting diabetes through vigilance in a person with a family history of the disease, said Annette Estes, associate director of the Autism Center and a study investigator.

"If you are at risk for diabetes, you look for signs," Estes said. With autism, the genetic "risk factors are present at birth. What we are doing is heightening the parents' awareness."

Though some parents report concerns early on, tiny babies by definition don't have autism. That's because they can't manifest such diagnostic symptoms as language deficits and repetitive rituals.

Yet researchers suspect that babies exhibit subtle clues that precede overt symptoms. For instance, healthy babies react visibly to changes in a person's expression, such as switching from cooing to a sad face. A baby who doesn't seem to register the change may warrant watching, Estes said.

"At 6 months, a baby has a limited repertoire of signs" of autism, she said. "The question is 'What are the real early signs?'"

To answer that, UW researchers will track 200 infant siblings, 6 months or younger, of kids with autism. The disorder's strong hereditary nature means that 10 or more of those babies will develop autism themselves. The odds for a typical American child are a little greater than 1 in 200.

The infants in the study will be randomly separated into two groups. Mothers in one group will be coached on engaging with their babies. Later, the children will receive up to 25 hours a week of a type of developmental intervention called the Denver Model that uses play to teach appropriate behaviors.

The other group will be monitored but not given treatment. All children will undergo regular brain imaging to measure brain activity during tasks.

In the UW researchers' view, autism is both congenital and perhaps avoidable.

Genetics is the main cause of autism, yet there are cases where one identical twin has it and the other does not. That leaves room for possible environmental causes, but none has yet been definitively isolated.

At the same time, researchers are learning that the brain is a dynamic organ, capable of forging new neural networks well beyond the womb. Just as playing the piano might form particular synaptic connections, Webb said, environmental manipulation could help calm a brain that is threatening to go haywire.

"The unknown is the family environment," Webb said. "We do not know if the amount or the quality of stimulation is the culprit."

That some families with autism reacted warily to the UW's study does not surprise Laura Schreibman, an autism investigator at the University of California, San Diego. Since it was first described in 1943, autism has largely remained a baffling challenge for parents and researchers alike.

In her book, "The Science and Fiction of Autism" (Harvard University Press, 2005), Schreibman debunks popular speculation about origins of and treatments for autism. They include the link to the measles/mumps/rubella vaccine (rejected by scientific consensus), chelation therapy, which is ridding the body of mercury and other metals (ineffective and potentially toxic) and the myth of the frigid "refrigerator" mother.

No cure has been found for autism. And only one type of therapy, behavioral intervention, has shown measurable, albeit mostly anecdotal, success in curbing outward signs of the disorder, Schreibman said.

"I feel so much for these poor parents," she said.

James, the Sammamish mother, wonders how she could have missed it.

As a first-time parent, she didn't know that healthy babies instinctively look up to share a laugh. She didn't notice that Ben never uttered the toddler's universal refrain: "Why?"

Ben, now 4 1/2, began behavioral therapy shortly after his diagnosis. He made quick strides. He has become more engaging and inquisitive, and sometimes even offers hugs.

Ben's brother, 15-month-old Hugh, is enrolled in the UW study to track whether he might share his sibling's affliction. That seems unlikely. Hugh loves to lock gazes with visitors, and expectantly crawls toward any interest that beckons.

Still, James said of her younger son, "You always have it in the back of your mind, 'Could it happen to him, too?'"

James is reassured that although Ben still has autism, his condition has become much less obvious. She doesn't know whether researchers can find a way to cure autism instead of merely masking it. But the distinction may not matter.

No comments: