Seeking autism's "signature"

Unique brain-wave patterns, spotted for the first time in autistic children, may help explain why they have so much trouble communicating.

Using an imaging helmet, researchers discovered what they believe are "signatures of autism" that show a delay in processing individual sounds.

That delay is only a fraction of a second, but when it's for every sound, the lag time can cascade into a major obstacle in speaking and understanding people, the researchers said.

Imagine if it took a tiny bit longer than normal to understand each syllable. By the end of a sentence, you'd be pretty confused.

The study authors believe that's what happens with autistic children, based on the brain-wave patterns detected in school-age children in their study.

The preliminary results need to be confirmed in younger children, but the researchers hope this technique could be used to help diagnose autism in children as young as age 1. That's at least a year earlier than usual, and it could mean behavior treatment much sooner.

Andrew Papanicolaou, director of the clinical neurosciences center at University of Texas' Houston campus, said the study makes a major contribution to autism research.

"It gives us a window through which we get a picture of some of the neurological conditions responsible for the peculiar behaviors in autism," said Papanicolaou, who was not involved in the research.

Study results were prepared for release today at the Radiological Society of North America meeting in Chicago.

The brain-wave study used noninvasive technology called magnetoencephalography, which measures magnetic fields generated in the brain.

Researchers at Children's Hospital of Philadelphia had 64 autistic children ages 6 to 15 listen through headphones to a series of rapid beeps while under the helmetlike device, which recorded the brain's response. Those brain waves were compared with responses in nonautistic children.

In autistic children, response to each sound was delayed by one-fiftieth of a second.

"We tend to speak at four syllables per second," said Timothy Roberts, the study's lead author and the hospital's vice chairman of research. If an autistic brain "is slow in processing a change in a syllable ... it could easily get to the point of being overloaded."

Experts say one in 150 U.S. children has autism, a disorder involving poor verbal communication, repetitive behaviors such as head-banging, and avoidance of physical or eye contact.

Among those in the study was Parker Leiby, a 9-year-old Mount Laurel, N.J., boy with mild autism and speech difficulties. He said he felt like an astronaut wearing that big helmet and called the whole experience "cool." Parker was diagnosed at age 2. Since then, he has had extensive treatment, including speech therapy. He's in a regular third-grade class, loves cross-country running and hopes to become an engineer.

Before the study last year, "we didn't have an answer" about his language difficulties, said Parker's mother, Kim. "It helped shed a lot of light."