Autistic toddlers’ brain research may help early diagnosis: Study

By Dr. Ananya Mandal, MDJun 23 2011

Researchers have noted that the brain activities of toddlers with autism appears to be out of sync at a very early stage -- a finding that sheds light on the biology of the condition and might help in earlier diagnosis. The study was published in the journal Neuron.

Autism is a complex brain disorder usually diagnosed in early childhood. It is characterized by difficulties in social interaction, communication, and understanding other people's emotions and behaviour. Autism disorders are diagnosed in up to one in 100 children in the United States and Europe and affect four times as many boys as girls, but the condition is very often misdiagnosed and doctors are keen to find biological measures to help pinpoint diagnosis and make it more accurate.

The team from Israel used functional magnetic resonance imaging (fMRI) to look at the brains of sleeping toddlers and found that certain types of neural activity are disrupted in autistic children, but not in typical children or in others with delayed language development.

Ilan Dinstein of Weizmann Institute of Science in Israel, who led the study, said, “What we looked at is how the activity is synchronized…And we found that the synchronization was different -- specifically in toddlers with autism and across the hemispheres (of the brain) in areas related to language and communication.”

Dinstein said, “There's a tremendous amount of misdiagnosis in many different forms…A child that might seem autistic at one and a half years old may turn out at three years old to have language delay or some other developmental disorder. So one of the reasons to look for a biological measure is to clarify the issue of diagnosis very early on.” Dinstein explained neural activity continues even during sleep and in a typical brain, normally correlates to certain patterns. Scientists believe the strength of synchronization between functionally related areas in the right and left hemispheres may be a measure of how well the brain is working.

The study results showed a specific abnormality in synchronization between two brain areas commonly associated with language and communication in 70 percent of toddlers with autism, but only in a handful of the typically developing toddlers or those with language delay.

Dinstein said that as a potential diagnostic tool, this biological measure was “a first step.” He said another useful aspect of this measure was its ability to be taken during natural sleep, bypassing potential problems of getting a very young child to cooperate with a test.

This study is part of a bigger research initiative carried out by scientists from the Autism Center of Excellence at the University of California, San Diego, headed by Professor Eric Courchesne, and was completed in collaboration with scientists at the Weizmann Institute and Carnegie Mellon University.