Enlargement of Cerebral Matter in Children with Autism
Gray and white matter volumes enlarged in young children with autism; cerebellar volumes unaffected
TUESDAY, Dec. 6 (HealthDay News) -- There is a generalized enlargement of gray and white matter cerebral volumes in young children with autism, although cerebellar volume remains normal, according to a study in the December issue of Archives of General Psychiatry.
Heather Cody Hazlett, Ph.D., of the University of North Carolina in Chapel Hill, and colleagues conducted magnetic resonance imaging of the brains of 51 children with autism and 25 healthy controls between the ages of 18 and 35 months. Controls consisted of normally developing children and those showing developmental delays. The researchers also retrospectively reviewed records of head circumference in 113 children with autism and 189 local controls from birth to age 3 years.
By age 2, there was significant enlargement in the cerebral cortex volumes of the autistic children, but not in the cerebellar volume. Their head circumference was normal at birth, but showed accelerated growth beginning at approximately 12 months of age.
"The data we present on the possible timing of brain enlargement in autism raise the possibility that the onset of autistic symptoms may be associated with postnatal changes in brain volume, and that there may exist a presymptomatic period in autism in which intervention may have more potent effects," the authors write.