Brain Abnormalities Identified in Autistic Brains
Mon Feb 11,2002
By Merritt McKinney
NEW YORK (Reuters Health) - Scientists have discovered abnormalities in the brains of people with autism that may explain some of the symptoms of the disorder.
Compared to people without autism, people with the disorder have more "minicolumns" in the brain, according to Dr. Manuel F. Casanova of the Medical College of Georgia in Augusta. Casanova is the lead author of a study published in the February 12th issue of the journal Neurology.
In an interview with Reuters Health, Casanova compared minicolumns to computer chips that process information. Each minicolumn is a "basic unit of the brain" that takes in information, processes it and then responds, he explained. "It's almost like a mini-brain," Casanova said.
Autism, which impairs a person's ability to communicate and form
relationships with other people, usually begins within the first few years of life. Autism may also affect the ability to respond properly to sights, sounds and touch. Though some children with the disorder are mentally impaired, about one third are "high-functioning," meaning that they have a normal or near-normal IQ.
Casanova and his colleagues looked at minicolumns in the brains of 9 people with autism who died and compared them to the brains of people without autism.
Minicolumns were smaller in people with autism but there were more of them than in the brains of nonautistic people, the researchers report. “There is an abnormality in this chip of the computer in the brain," Casanova said.
Having too many minicolumns may cause people with autism to receive more signals than other people, according to the Georgia researcher. This may cause them to "be overpowered by the amount of information" coming into their brain, he said. This may explain some of the abnormal behavior that occurs in people with autism, according to Casanova. He noted that autistic people often do not look people directly in the face. It is possible, he said, that they look away to keep from being overpowered by the information they receive when they look at someone eye-to-eye.
Casanova said that the presence of many minicolumns may also explain why some people with autism have special abilities. These extra "chips" in the brain's computer "may account for some of the savant skills," he said.
According to Casanova, the research "raises many more questions than it really answers." He and his colleagues plan to continue studying minicolumns in the brains of people with autism.
Within the next year, Casanova said, they hope to begin a clinical trial of anti-convulsive medications in autistic patients. He noted that many people with autism eventually develop epilepsy. By intervening early, it may be possible to affect the course of the disorder, according to Casanova. The researchers plan to see whether the drug therapy has any effect on minicolumns in the brain.
SOURCE: Neurology 2002;58:428-432.
Reprinted with Permission
