fMRI sheds light on diagnosis and management of autism

Functional MRI can identify brain activity patterns unique to people with autism spectrum disorders, according to a study published in February. Findings suggest that fMRI-based measurements could improve the diagnosis and treatment of these conditions.

Public and scientific interest in autism spectrum disorders (ASD) has been growing steadily in recent years. The increased attention among researchers on autism, Asperger syndrome, and pervasive developmental disorders not otherwise specified (PDD-NOS) - the three main forms of ASD - may have also led to an increased number of misdiagnosed cases.

Using fMRI, researchers in Texas and Alabama devised a technique for an objective, quantitative assessment of brain activity in people with ASD. Principal investigator Pearl H. Chiu, Ph.D., an assistant professor of neuroscience at Baylor College of Medicine in Houston, and colleagues asked high-functioning people with ASD and normal subjects to play an interpersonal game that involved social trust as they underwent fMR scans.

People with ASD played the game the same as the normal controls. The investigators found that the pattern of activity in the cingulate cortex of people with ASD, however, indicated a diminished perception of themselves in a social interaction. This activity pattern resembled one seen in normal people when they play against a computer. Researchers published findings in the Feb. 7 issue of Neuron.

The ability to quantify brain activity in people with ASD may serve as a diagnostic tool, identify subtypes of autism, or be used to seek covariates in genetic databases, the researchers said. Study findings suggest that a quantitative analysis of neural responses on such simple tasks as watching videos may be of diagnostic and therapeutic utility.

Study findings may also imply that some mechanisms of social interaction are intact in some ASD patients, since the distinction between "self" and "other" involves higher-order mentalizing, according to Chris and Uta Frith from the Institute of Cognitive Neuroscience at University College London in the U.K.

"You care what another person thinks of you, and even further, you care that the other person trusts you. You would not do this when playing against a computer. In autism, there is no difference," the Friths said in a preview published in the same publication.

For more information from the Diagnostic Imaging archives:

Brain imaging focuses on connectivity and activation

Autistic children face fMRI's gaze

Functional MRI reveals clues to social behavior

fMRI links autism with white matter anomaly