Autism is a neurodevelopmental disorder that is characterized by impaired communication, dysfunctional social interaction, and repetitive behavior. Autism spectrum disorder is a group of two other clinical entities that share common features with autism. The two other disorders are Asperger syndrome and pervasive developmental disorder, not otherwise specified. In order for the diagnosis of autism to be made, the symptoms and characteristic features need to be present before the age of three. There is a strong genetic and environmental influence in the development of autism. Typically, the disorder is diagnosed on the basis of clinical characteristic and features.
Physicians and neuro-developmental scientists have tried to identify a simple and easy test or diagnostic procedure to aide in the identification of children who are at increased risk for developing the disorder. Finding such a test has been very elusive and difficult due to the fact that this brain disorder manifests as complex behavioral characteristics. The prevalence of autism spectrum disorder is estimated to occur in one of every one hundred children. As a result, the identification of an accurate and clinically available diagnostic test would be greatly beneficial to a large number of children and their families.
Researchers from Harvard Medical School have discovered that children who are autistic have brain wave patterns that can be identified on electroencephalography (EEG). Dr. Frank Duffy and Dr. Heidelise Als, working at the Boston Children’s Hospital, reported their results in the journal BMC Medicine. The investigators studied 463 children with a diagnosis of autism spectrum disorder and 571 children that were neuro-typical controls. After analyzing their data, the researchers were able to identify 33 EEG patterns that were specific for children with the diagnosis of autism. Using the brain wave pattern that was identified, the researchers were able to correctly identify autistic children in 90% of cases.
The authors of the study speculate that their finding of a specific EEG pattern that is characteristic for autism may aide in the early diagnosis of autism. It would be helpful to have early diagnostic tests so that behavioral interventions can be implemented sooner, which may have a positive influence on the long term outcome of the disorder. Future study should focus on whether this procedure can be used outside the research setting, and thus be able to be more widely available.
Frank H Duffy and Heidelise Als “A stable pattern of EEG spectral coherence distinguishes children with autism from neuro-typical controls – a large case control study” published online June 26, 2012 BMC Medicine 2012, 10:64 doi:10.1186/1741-7015-10-64