December 7, 2010

First Biological Test To Detect Autism

(Ivanhoe Newswire) -- Everyday scientists are taking steps towards discovering cures for diseases, vaccines for infections, and tests to detect illnesses.  But every so often, a giant leap is made in the development of medical treatments.  Well, this is one of those cases.  Researchers at Harvard-affiliated McLean Hospital and the University of Utah have developed the utmost biologically based test for autism to date.  In fact, the test was able to detect the disorder in individuals with high-functioning autism with 94 percent accuracy.

The test uses MRI to measure deviations in brain circuitry, and could someday replace the subjective test currently implemented to identify autism.  Furthermore, it may lead to a superior understanding of the disorder, offering better management and treatment protocol for affected individuals.

"This is not yet ready for prime time use in the clinic yet, but the findings are the most promising thus far," which Nicholas Lange, ScD, Associate Professor of Psychiatry at Harvard Medical School, director of the Neurostatistics Laboratory at McLean and lead author of the study, was quoted as saying.

"Indeed, we have new ways to discover more about the biological basis of autism and how to improve the lives of individuals with the disorder," which Janet Lainhart, MD, senior author and Principal Investigator of the research at the University of Utah, was quoted as saying.

The collaborative research group used the test on two separate groups.  The first consisted of individuals who had formerly been diagnosed with high-functioning autism by means of the standard scoring system.  That system in due course is based on evaluating patients and questioning their parents regarding their functionality in myriad areas including language, social functioning, and behavior.  The subsequent group under study was a control group consisting of normally developing individuals.

Both groups were put in an MRI scanner that was programmed to be unreservedly responsive to water diffusion along the axons of the brain in an effort to measure microscopic features of the brain's intricate circuitry. 

The test, which employs Diffusion Tensor Imaging, "provides pictures and measurements of the microscopic fiber structures of the brain that enable language, social and emotional functioning, which can reveal deviations that are not found in those without autism," according to Lange.

By meticulously measuring six distinctive aspects of the brain's circuitry, the test was able to accurately differentiate those who had previously been diagnosed with autism with 94 percent accuracy.

A repeat study implementing two unrelated sets of subjects illustrated the same elevated level of performance.

"The differences picked up on the study correlate with clinical symptoms that are part of the features of autism," Lainhart said.  "There is less directional flow to and from brain regions where there should be more information exchange."

Researchers will continue to study and develop the test, with further findings due out in a year or two.  Potential studies will examine patients with high-severity autism, younger children, in addition to patients with such conditions as developmental language disorders, attention deficit hyperactive disorder and obsessive-compulsive disorder, who ultimately do not have autism.

If the test demonstrates further success, it could possibly change the existing system of diagnosing autism, which is not biologically based.

What's more, it could someday lead to pinpointing how autism develops.  "We can gain a better understanding of how this disorder arises and changes over the lifetime of an individual, and derive more effective treatments," concluded Lainhart.

SOURCE: Autism Research, 29 November 2010