MRI Scans May Help Evaluate Asperger’s Syndrome

Researchers Use Advanced MRI Scans to Analyze Brain Activity of People With Asperger’s

From the WebMD Archives

Dec. 6, 2010 (Chicago) -- Researchers are a step closer to developing new treatments that are tailored to the individual needs of people with Asperger’s syndrome and other types of autism.

The technique uses two advanced MRI scanning techniques to produce a detailed map of the brain’s wiring in six regions responsible for language, social, and emotional function.

The work is very preliminary. But the hope is that the approach will also lead to an imaging test that may help to diagnose autism, says Sophia Muller, MD, a radiologist at the University of Munich, Germany.

"The method could also potentially be used to evaluate whether drugs are working," she tells WebMD.

Symptoms of Asperger's Syndrome

Asperger's syndrome (AS) is one of two main types of autism that often goes unrecognized until late in childhood or even adulthood.

People with Asperger's syndrome often find themselves somewhat disconnected from others. Some people with Asperger's syndrome obsess over unusual things, and communication can be a great challenge. People with AS generally have difficulty interacting with others and often are awkward in social situations.

Currently, AS and other types of autism are typically diagnosed through observations, along with educational and psychological testing. There are no medications to cure Asperger's syndrome, although drugs may be used to treat specific symptoms, such as anxiety, depression, hyperactivity, and obsessive-compulsive behavior.

If the new findings hold up in larger studies, the sophisticated imaging scans can be used to pinpoint disturbed brain wiring and activity in people with Asperger's and other types of autism, thereby aiding in the diagnosis, Muller says. Drugs that target those brain regions can also be developed, she says.

The new test is not the only test in development for Asperger's syndrome or other types of autism. Blood and urine tests are also being looked at in the U.S. and abroad, along with MRI scans that may help diagnose autism.

Analyzing Results of MRI Scans

For the new study, Muller and colleagues used functional magnetic resonance imaging (functional MRI) and diffusion MRI to study six major networks in the brains of 12 people with Asperger's and 12 people with no cognitive problems.

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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."

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The increased activity in the attention network and the decreased activity in some other major brain areas may account for the fact the "people with Asperger's syndrome exhibit hyper-concentration but at the same time are easily distracted and can’t focus," he tells WebMD.

This study was presented at a medical conference. The findings should be considered preliminary as they have not yet undergone the "peer review" process, in which outside experts scrutinize the data prior to publication in a medical journal.

WebMD Health News Reviewed by Laura J. Martin, MD on December 06, 2010

Sources

SOURCES:

Radiological Society of North America, Chicago, Nov. 28-Dec.3, 2010.

Sophia Muller, MD, radiologist, University of Munich, Germany.

Robert Zimmerman, MD, professor of radiology, Weill-Cornell Medical Center, New York City.

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