RT Journal Article
SR Electronic
T1 Longitudinal Magnetic Resonance Imaging Study of Cortical Development through Early Childhood in Autism
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 4419
OP 4427
DO 10.1523/JNEUROSCI.5714-09.2010
VO 30
IS 12
A1 Cynthia M. Schumann
A1 Cinnamon S. Bloss
A1 Cynthia Carter Barnes
A1 Graham M. Wideman
A1 Ruth A. Carper
A1 Natacha Akshoomoff
A1 Karen Pierce
A1 Donald Hagler
A1 Nicholas Schork
A1 Catherine Lord
A1 Eric Courchesne
YR 2010
UL http://www.jneurosci.org/content/30/12/4419.abstract
AB Cross-sectional magnetic resonance imaging (MRI) studies have long hypothesized that the brain in children with autism undergoes an abnormal growth trajectory that includes a period of early overgrowth; however, this has never been confirmed by a longitudinal study. We performed the first longitudinal study of brain growth in toddlers at the time symptoms of autism are becoming clinically apparent using structural MRI scans at multiple time points beginning at 1.5 years up to 5 years of age. We collected 193 scans on 41 toddlers who received a confirmed diagnosis of autistic disorder at ∼48 months of age and 44 typically developing controls. By 2.5 years of age, both cerebral gray and white matter were significantly enlarged in toddlers with autistic disorder, with the most severe enlargement occurring in frontal, temporal, and cingulate cortices. In the longitudinal analyses, which we accounted for age and gender effect, we found that all regions (cerebral gray, cerebral white, frontal gray, temporal gray, cingulate gray, and parietal gray) except occipital gray developed at an abnormal growth rate in toddlers with autistic disorder that was mainly characterized by a quadratic age effect. Females with autistic disorder displayed a more pronounced abnormal growth profile in more brain regions than males with the disorder. Given that overgrowth clearly begins before 2 years of age, future longitudinal studies would benefit from inclusion of even younger populations as well as further characterization of genetic and other biomarkers to determine the underlying neuropathological processes causing the onset of autistic symptoms.