Cortical Anatomy in Autism Spectrum Disorder: An In Vivo MRI Study on the Effect of Age

Abstract

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.

Effects of age and symptomatology on cortical thickness in autism spectrum disorders

“…To date, few studies have investigated age-related changes in cortical thickness in individuals with ASD and collectively they suggest a complex pattern of cortical thickness maturation in this group. In agreement with the current findings, studies that included participants across a wide age range (Raznahan et al, 2010;Scheel et al, 2011) found more regions with little to no change in cortical thickness in individuals with ASD. In comparison, studies with narrower age ranges report that the cortex thins with age in individuals with ASD.…”

“…To our knowledge, no longitudinal studies in individuals with ASD have examined cortical thickness development across a wide age-range. Cross-sectional studies in ASD suggest atypical cortical thickness changes between childhood and adulthood in individuals with ASD (Mak-Fan, Taylor, Roberts, & Raznahan et al, 2010;Scheel et al, 2011;Wallace, Dankner, Kenworthy, Giedd, & Martin, 2010). In children with ASD aged 6-15 years, Mak-Fan et al (2011) reported decreased cortical thickness with age across the entire brain, as well as in the frontal and parietal lobes; however group differences were not found.…”

“…In older samples, studies have observed thinner cortices with increasing age in participants with ASD relative to typically developing controls in the left posterior part of the superior temporal sulcus (Scheel et al, 2011;Wallace et al, 2010), left cuneus (Scheel et al, 2011) and right paracentral lobule (PCL) (Scheel et al, 2011). In contrast, brain regions such as the left supramarginal gyrus (Scheel et al, 2011), left inferior parietal lobule (Scheel et al, 2011), left middle temporal gyrus (Raznahan et al, 2010), right postcentral gyrus (Scheel et al, 2011) and right fusiform (Raznahan et al, 2010), show decreased cortical thickness across age in typically developing individuals, but little to no change in individuals with ASD. These findings suggest a maturational process that is both atypical and complex in ASD.…”

Can Magnetic Resonance Imaging Aid Diagnosis of the Autism Spectrum?: Table 1.

“…Given that imaging findings in autism often are not robust because of the inherent heterogeneity of the autism spectrum and small sample sizes, this study's multiparameter classifier should demonstrate high levels of sensitivity with additional samples of autistic participants that vary in age and autistic characteristics. In many of the frontal, temporal, and parietal regions identified by the Ecker et al (2010b) classifier, Raznahan et al (2010) found that younger autistic participants tend to have lower cortical thickness and older autistic participants tend to have greater cortical thickness compared with nonautistic participants. The role of age in autistic and non-autistic differences in cortical thickness complicates the replicability of the Ecker et al (2010b) classifier with younger samples.…”

Fast and robust hybrid framework for infant brain classification from structural MRI : a case study for early diagnosis of autism.

“…The extraction of appropriate features for brain classification is an essential, yet challenging research area. Recent neuropathological studies show an increasing evidence that children diagnosed with autism spectrum disorder have anatomical differences from controls in cortical volume (CV) [59]. Another study [60] observed differences between the autism and control subjects in total gray matter volumes over time with significantly greater decreases in the autism group compared with control subjects, in addition to the differences in cortical thickness (CT) over time with decreases in the autism group compared with control subjects in several brain regions including the frontal lobe.…”