Progress in the diagnosis and treatment of autism spectrum disorders is being made on a number of fronts, including genetics, neurobiology, clinical features, the need for early identification and early intervention, and educational and behavioral approaches.
Explore this issue:December 2008
Features of the Autism Spectrum
Neurobiology researchers have determined that as many of 30% of electroencephalograms of children with autism spectrum disorders have abnormalities, and that seizures occur with increased frequency, according to Leslie Rubin, MD, President and Founder of the Institute for the Study of Disadvantage and Disability, a Visiting Scholar in the Department of Pediatrics at Morehouse University School of Medicine in Atlanta, and Director of the Autism Program at Children’s Healthcare of Atlanta’s Hughes Spalding Children’s Hospital. Research has found neuropathology in the amygdala, hippocampus, septum, mammilary bodies, and the cerebellum-mainly in the limbic system, which has to do with contact with the outside world, he said. Also, children with autism tend to have a larger head circumference, which is not necessarily present at birth, but which appears to manifest in the first couple of years of life, he added.
Genetic studies show a 75% increased risk of a sibling having an autism spectrum disorder if another child had the condition. There is a 10% to 40% increased risk of an autism spectrum disorder if there are other siblings with related disorders in the family. In studies of twins, there is a 75% to 90% concordance in monozygotic twins but only a 5% to 10% concordance in same-sex dizygotic twins.
Dr. Rubin said that in treating children on the autism spectrum, clinicians must realize they are basically in the dark in trying to evaluate the child’s intelligence levels. We do not know how clever the children are if they cannot speak to us, he said. You should not assume that if they cannot speak, they cannot do intelligent things or cannot take information in. Although intellectual abilities may vary, we have to assume that the children are intellectually capable even if they cannot demonstrate this, and we have to do everything we can as soon as we can to make sure each child reaches his or her optimal developmental function.
-Leslie Rubin, MD
Another cardinal feature of autism spectrum disorders is limited social interaction. The children tend to be by themselves and play by themselves. If there are other children around, they often drift to the periphery of the group. They also tend to have limited eye contact. It’s not that they have no eye contact with others, he said, it is that the eye contact does not have the same qualitative interactive engagement that one usually expects. Often, they are anxious about meeting new people and encountering new situations, and are reluctant to relate on terms other than their own, but you can encourage them be engaged with others.