Researchers (from left) Eric Courchesne, Lisa Eyler and Karen Pierce at the UCSD Autism Center of Excellence last week. John Gastaldo / U-T
Toddler brain scans part of UCSD study
San Diego researchers who scanned the brains of sleeping toddlers have opened a window into the mystery of what goes wrong in the mind of a child with autism, an important step toward diagnosing the condition earlier and determining what treatments work best.
Scientists at the UCSD Autism Center of Excellence who performed the MRI scans as part of a three-year study had to overcome the challenge of getting their young, and often rambunctious, subjects to remain perfectly still so that clear images could be produced.
They did it by using a trick known to every parent.
Children were kept active for an entire day then ate a large meal before arriving at the La Jolla center for their scans. Most of the exhausted toddlers quickly fell into a deep sleep that lasted for the duration of the test.
While it’s not unusual to use MRI imaging to observe the brain functions of children, the practice rarely has been used on youngsters with autism because of the difficulty of having them remain motionless for extended lengths of time, said neuroscientist Eric Courchesne, director of the UCSD center.
Experts said the research marked an important milestone in the effort to decipher a debilitating condition whose cause and cure remain unknown.
“It’s a very exciting study,” said David Mandell, associate director of the Center for Autism Research at Children’s Hospital of Philadelphia.
Mandell led a panel of reviewers who selected the UCSD study to be among the papers presented at the International Meeting for Autism Research, which was recently held in Philadelphia. The local study was among four highlighted during a news conference at the gathering.
The UCSD researchers said they will submit the study to a medical journal for publication.
“It presents a new paradigm of how you can study the brain” of children with autism, Mandell said. “Since we can start them so young, we can watch those brains develop.”
About 1 in 110 children in the United States have autism spectrum disorders, a range of developmental disabilities that include autism and Asperger’s syndrome, according to a December report by the federal Centers for Disease Control and Prevention. That amount represented a significant increase over the agency’s previous estimate that 1 in 150 children had the disorders.
The UCSD study enrolled 43 children between the ages of 13 months and 4 years. They followed the children for two years, long enough to diagnose 23 with autism. The others developed normally.
Once the children were sleeping, they listened to a recording of a woman reading a bedtime story through earphones.
The researchers found abnormally low activity in the left temporal cortex of the brains of the children with autism. That area, just above the left ear, has long been suspected of playing a part in the developmental disorder because of its critical role in learning language.
Communication problems, along with lagging social skills, are among the main symptoms of autism.
“When language is first being learned, there is some reason why (youngsters with autism) can’t use the left temporal cortex,” Courchesne said.
The scans indicated that brain activity in the toddlers with autism shifted to the right temporal cortex, a region normally focused on social skills development.
The change could help explain why autism affects both the mechanics of language and social elements of communication, Courchesne said.
“Think of it as being crowded out,” he said.
More immediately, the discovery of inactivity in the left temporal cortex appears to offer the first measurable biological indicator signaling an increased risk for developing autism, said Karen Pierce, director of research at the UCSD center. Pierce collaborated on the study with Courchesne and assistant psychiatry professor Lisa Eyler.
Most children with autism aren’t diagnosed until they are 3 years or older, when communication and social difficulties become more noticeable.
“If you start treatment much earlier, then the chance of having a good outcome is greatly improved,” Pierce said.
Lena Medina, whose 3-year-old son Elan is autistic, said she knows the benefits of early intervention. Elan, who was part of the study, started receiving daily, two-hour treatment sessions in his Rancho Peñasquitos home shortly after undergoing a brain scan and being identified as having a high risk for developing autism.
Before the treatment, Elan wasn’t able to communicate verbally, Medina said.
“Now, his vocabulary is well over 100 words, and he speaks to me in full sentences,” she said. “He tells me what he wants.”
The study could lead to toddlers with more subtle symptoms, such as lacking curiosity about their surroundings or avoiding eye contact, being scanned for the left temporal cortex inactivity and placed on an autism treatment regimen at a young age.
Before that happens, other scientists must replicate the findings of the UCSD team using larger numbers of test subjects, Mandell said.
Scanning for brain abnormality also could help fine-tune treatments for autism, Courchesne said.
The UCSD study, which will continue for two more years, was funded through an $11 million grant from the National Institute of Mental Health. The money also is paying for an effort to get more than 130 pediatricians in San Diego County to screen every baby for early signs of autism at their 1-year-old checkup and to refer those with symptoms to the UCSD center for evaluation.
Among the 10,000 children evaluated through the program, 37 were diagnosed with autism and 63 showed other signs of developmental delays, Pierce said.