MRI Scans May Help Evaluate Asperger’s Syndrome
Researchers Use Advanced MRI Scans to Analyze Brain Activity of People With Asperger’s
Analyzing Results of MRI Scans continued...
Functional MRI allows doctors to look at how blood flow increases in response to brain activity. Diffusion MRI, also known as diffuse tensor imaging (DTI), is used to look at connections between brain cells, thereby providing a road map of the brain.
The average age of the people with AS was 36 and the average age of the cognitively healthy people was 33. All underwent the imaging scans while they were resting, with their eyes closed.
Results of the scanning tests "provide the first links of disturbed functional connectivity patterns that are reasonably associated to the core behavioral problems of patients with Asperger’s syndrome," Muller says.
She presented the study here today at the annual meeting of the Radiological Society of North America.
Tracking Brain Activity in Asperger’s Patients
Results of the functional and diffusion MRI scans showed that compared with people with no cognitive problems, people with Asperger's syndrome:
- Have increased activation in the brain network that governs attention. "This might explain hyper-arousal and [obsessing] that are typical in Asperger’s syndrome," Muller says.
- Have detected decreased activity and fewer fibers connecting cells in the brain area that governs the resting state of the brain. This network "is used to explore the intentions of other people, a function that is strongly impaired in autism," she says.
- Have decreased activity in motor areas of the brain. "This may account for the known clumsiness in Asperger's patients," Muller says.
- Have decreased activity in the brain network that is active when you’re thinking about yourself, other people and the relation between the two, she says. "This might correlate to the increase in apathy and the decrease in social interaction exhibited by people with Asperger's syndrome," she says.
There was no difference in activity in the visual and auditory brain regions between the two groups. "This suggests that symptoms are not caused by altered perception of visual and auditory stimuli but by aberrant processing of sensory information," Muller says.
Robert Zimmerman, MD, professor of radiology at Weill-Cornell Medical Center in New York City, says that while the study is small, "it is starting to give us a better understanding of the brain, how it works differently in Asperger's and in [cognitively] normal people."