Doctors study connection between children's brain size, autism

[Guest guest]

http://www.therepublic.com/view/story/MED-AUTISM_5022673/MED-AUTISM_5022673/

Doctors study connection between children's brain size, autism

By Delthia Ricks Newsday

First Posted: May 02, 2011 - 6:33 pm

Last Updated: May 02, 2011 - 6:33 pm

MELVILLE, N.Y. — Medical investigators have found that children with autism have

larger brains than children without the condition, raising questions about

differences in the neurological development of affected youngsters.

The research, which used magnetic resonance imaging and was published in the

Archives of General Psychiatry, noted the difference in brain size appears

related to increased rates of brain growth before age 2.

Although smaller studies in the past have pointed to a connection between autism

and an increase in brain size, the new research, which compares 59 children with

autism to 38 children without the condition, is the first to define the timing

of brain growth in children with autism.

Dr. Adesman, chief of developmental and behavioral pediatrics at the

Cohen Children's Medical Center of New York in New Hyde Park, said the new

finding jibes with other studies showing that some children with autism have a

somewhat larger head size. The increase in head circumference, Adesman said, has

its onset around 1 year of age.

" This new study, using sophisticated brain-imaging techniques at 2 years and

again at 4 to 5 years, confirms not only that children with autism have brain

overgrowth by the age of 2, but that this difference in size is stable, not

progressive, during a child's preschool years, " Adesman said.

To arrive at their conclusions on timing of spurts in brain growth, Dr.

Cody Hazlett and colleagues at the University of North Carolina performed

imaging studies on the two sets of children and conducted behavioral

assessments.

Two years after the first round of studies, when the children had reached 4 to 5

years old, medical investigators repeated each of the steps, again performing

MRIs and conducting behavioral assessments. On the follow-up evaluation,

however, brain scans were evaluated for the volume of the brain's gray and white

matter. Gray matter refers to the neurons — brain cells — involved in all higher

human functioning: memory, hearing, vision, emotions, speech and language. White

matter is made up of highly insulated cells and comprises the tissue through

which signals pass to reach different regions of gray matter.

Hazlett found overall enlargement of the brain in children with autism at all

ages studied.

" Although this study has no direct clinical implications, " Adesman said, " it

does encourage researchers to more closely evaluate brain development in the

months just before and after a child's first birthday, since this is when early

signs of autism often manifest initially and when changes in head size also

become evident. "

———

© 2011, Newsday.