Advanced MRI Techniques Could Diagnose Aspergers Syndrome
Currently, Asperger’s Syndrome and other forms of autism are primarily diagnosed through observation and psychological testing. But researchers are now getting closer to developing techniques, such as advanced MRI scanning, that could produce a detailed map of certain regions of the brain that may help lead to an imaging test to diagnose a wide range of autism spectrum disorders.
Functional MRI and Diffusion MRI Map Brain Activity
Sophia Muller MD, a radiologist at the University of Munich Germany, used functional magnetic resonance imaging (functional MRI or fMRI) and diffusion MRI (also known as diffuse tensor imaging or DTI) to study six major networks in the brains of 12 people with Asperger’s syndrome and 12 cognitively normal subjects. The average age of the patients was 33 to 36. The six regions are responsible for language, social and emotional function.
A functional MRI looks at how blood flow increases in response to brain activity. Diffusion MRI looks at the connections between brain cells.
Dr. Muller reports that people with Asperger’s have increased activation in the brain network that governs attention, possibly explaining why patients have hyperarousal and obsession tendencies. The patients also have decreased activity and fewer fibers connecting cells in the area of the brain that governs the resting state. This network is also used to explore the intentions of others, a function strongly impaired in autism.
Asperger’s patients are also known to be clumsy and socially awkward. Muller says there is also decreased activity in motor areas of the brain, explaining the clumsiness. There is also decreased activity in a portion of the brain correlated with apathy and social interaction.
Dr. Muller says that the 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.” The hope is not only to use the imaging tests for earlier diagnosis, but also to help discover treatments that target these areas of the brain and to monitor their effectiveness once prescribed.
The results of the preliminary study were presented at the annual meeting of the Radiological Society of North America.