Parents everywhere know the perils of “the terrible twos,” but when toddlers’ natural misbehaviours are accompanied by developmental setbacks, they could point to something more serious. Much research is being done about regressive autistic spectrum disorder (RASD), a form of autism in which children slowly lose much of their developing language and social skills. Gerry A. Stefanatos, an associate professor in the Department of Communication Sciences and Disorders in Temple University’s College of Health Professions, estimates that about 25 to 30% of children eventually diagnosed with autism have the disorder.
Children with RASD seem to develop normally until 18 to 24 months. At that point, they have acquired a small vocabulary and social behaviours, but over the course of weeks or months lose their speech and no longer use words they had learned previously. They have problems comprehending and lose the ability to follow commands.
“One of the more obvious cues for parents is if the child no longer responds to his or her own name,” said Stefanatos. “Oftentimes this is accompanied by deterioration in behaviour. The child can become irritable, prone to tantrums.”
Among the many potential causes of regression, Stefanatos said healthcare providers or autism specialists who suspect RASD should look for evidence of an electroencephalographic (EEG) abnormality, which might suggest an epileptic or seizure disorder. An EEG measures electrical activity produced by the brain and is recorded from electrodes placed on the scalp. Seizure-related brain activity can act like “electrical noise” and interfere with the function of areas of the brain responsible for different areas of development. This noise can potentially be disruptive to the wiring of connections between brain cells developing at that stage. In these cases, medications may reduce disruptive electrical discharges so they do not have a negative influence on neurological development.
“When it’s treated, either behaviourally or medically, there can be a significant improvement in behaviour and development,” said Stefanatos. “This is one reason why it’s important to identify RASD as early as possible.”
More research is required to explore the similarities and differences between RASD and ASD.
Image: Gerry A. Stefanatos, D.Phil. (Photo by Joseph V. Labolito/Temple University)
Stefanatos, G.A.(2008, December). Regression in autistic spectrum disorders. Neuropsychology Review, 18(4). 305–319. Retrieved February 5, 2009, from SpringerLink at http://www.springerlink.com/content/85g15p377-4785p61/. The full article can be accessed online for $34.
Temple University (2008, December 17). When it’s more than the “terrible twos”. Retrieved February 5, 2009, from http://www.temple.edu/newsroom/2008_2009/12/stories/rasd.htm