Study Of Emotional Facial Processing Related Brain Structural Network In2-to3-Year-Old Children With Autism Spectrum Disorder

[Objective]To evaluate brain regions associated with emotional facial processing in2-to3-year old children with autism spectrum disorder (ASD) in comparison with developmental delay (DD), and to investigate the correlation between the abnormal change of these brain regions and socio-emotional function impairment.[Methods]Magnetic resonance imaging (MRI) scans were acquired in29ASD children and27age, sex and development quotient (DQ) matched DD. Amygdala was manually traced, while fusiform gyrus, superior temporal sulcus, superior temporal gyrus, inferior occipital gyrus, orbital frontal cortex, anterior cingulated cortex, pars opercularis of inferior frontal gyrus and intracranial volumn (ICV) were measured using FreeSurfer Software for the comparison of cortical thickness and volume. Correlation between abnormal change of related brain regions and socio-emotional function, assessed by Communication and Symbolic Behavior Scales Developmental Profile (CSBS-DP) Infant-Toddler Checklist and Autism Diagnostic Interview-Revised (ADI-R), were examined.[Results](1) Compared with DD, the volume of bilateral amygdala, bilateral fusiform gyrus, bilateral superior temporal gyrus, bilateral anterior cingulated cortex and left pars opercularis of inferior frontal gyrus was significantly lager in ASD with covarying for age, sex and ICV (p<0.05), particularly in the left amygdala, right superior temporal gyrus and left anterior cingulated cortex (p<0.01).(2) Cortical thickness of fusiform gyrus, superior temporal sulcus, superior temporal gyrus, inferior occipital gyrus, orbital frontal cortex, anterior cingulated cortex and pars opercularis of inferior frontal gyrus did not differ between groups (p>0.05).(3) After age, sex and DQ were controlled, left amygdala size in children with DD had a trend negatively correlating with "emotion and eye gaze" area in CSBS-DP Infant-Toddler Checklist (r=-0.40, p=0.087), while right amygdala size was significantly associated with social (r=-0.48, p=0.040) and communication (r=-0.58, p=0.009) performance measured by ADI-R in DD group, but not in ASD group. In ASD group, the volume of right fusiform gyrus was associated with symbolic composite (r=-0.48, p=0.023), the volume of right superior temporal gyrus had a trend negatively correlated with "emotion and eye gaze" area (r=-0.38, p=0.077), and the volume of right anterior cingulated cortex negatively correlated with "emotion and eye gaze" area (r=-0.51, p=0.016), but such correlation did not show up in DD group.[Conclusion]Our findings reveal that the abnormal pattern of emotional facial processing related brain structural network is present before3years of age in children with ASD, particularly in left amygdala, right superior temporal gyrus and left anterior cingulated cortex. The abnormal enlargement of related brain regions may be associated with socio-emotional function impairment in ASD.