Cerebral Cortex Advance Access published online on October 9, 2009
Cerebral Cortex, doi:10.1093/cercor/bhp198
Cortical Anatomy in Autism Spectrum Disorder: An In Vivo MRI Study on the Effect of Age
Paus2,51 Department of Child and Adolescent Psychiatry, Institute of Psychiatry, King's College London, SE5 8AF, UK, 2 Brain and Body Center, University of Nottingham, NG7 2RD, UK, 3 Department of Psychological Medicine, Section of Brain Maturation, Institute of Psychiatry, King's College London, SE5 8AF, UK, 4 MRC Center for Social Genetic and Developmental Psychiatry, Institute of Psychiatry, King's College London, SE5 8AF, UK, 5 Montreal Neurological Institute, McGill University, H3A 2B4, Canada
Address correspondence to Dr Armin Raznahan. Email: armin.raznahan{at}iop.kcl.ac.uk.
There is increasing evidence that children with autism spectrum disorder (ASD) have age-related differences from controls in cortical volume (CV). It is less clear, however, if these persist in adulthood and whether these reflect alterations in cortical thickness (CT) or cortical surface area (SA). Hence, we used magnetic resonance imaging to investigate the relationship between age and CV, CT, and SA in 127 males aged 10 through 60 years (76 with ASD and 51 healthy controls). "Regional" analyses (using cortical parcellation) identified significant age-by-group interactions in both CV and CT (but not SA) in the temporal lobes and within these the fusiform and middle temporal gyri. Spatially nonbiased "vertex-based" analysis replicated these results and identified additional "age-by-group" interactions for CT within superior temporal, inferior and medial frontal, and inferior parietal cortices. Here, CV and CT were 1) significantly negatively correlated with age in controls, but not in ASD, and 2) smaller in ASD than controls in childhood but vice versa in adulthood. Our findings suggest that CV dysmaturation in ASD extends beyond childhood, affects brain regions crucial to social cognition and language, and is driven by CT dysmaturation. This may reflect primary abnormalities in cortical plasticity and/or be secondary to disturbed interactions between individuals with ASD and their environment.
Key Words: age autism brain cortical thickness MRI
Received for publication February 4, 2009. Revision received August 14, 2009. Accepted for publication August 20, 2009.