Increased Gray Matter Volume and Resting-State Functional Connectivity in Somatosensory Cortex and their Relationship with Autistic Symptoms in Young Boys with Autism Spectrum Disorder.

Jia Wang,Wei Xia,Huafu Chen,Heng Chen,Qiong Wu,Lijie Wu,Kuang Fu,Xiaonan Guo,Xujun Duan,Lei Chen

doi:10.3389/fphys.2017.00588

Abstract

Autism spectrum disorder (ASD) has been widely recognized as a complex neurodevelopmental disorder. A large number of neuroimaging studies suggest abnormalities in brain structure and function of patients with ASD, but there is still no consistent conclusion. We sought to investigate both of the structural and functional brain changes in 3–7-year-old children with ASD compared with typically developing controls (TDs), and to assess whether these alterations are associated with autistic behavioral symptoms. Firstly, we applied an optimized method of voxel-based morphometry (VBM) analysis on structural magnetic resonance imaging (sMRI) data to assess the differences of gray matter volume (GMV) between 31 autistic boys aged 3–7 and 31 age- and handness-matched male TDs. Secondly, we used clusters with between-group differences as seed regions to generate intrinsic functional connectivity maps based on resting-state functional connectivity magnetic resonance imaging (rs-fcMRI) in order to evaluate the functional impairments induced by structural alterations. Brain-behavior correlations were assessed among GMV, functional connectivity and symptom severity in children with ASD. VBM analyses revealed increased GMV in left superior temporal gyrus (STG) and left postcentral gyrus (PCG) in ASD children, comparing with TDs. Using left PCG as a seed region, ASD children displayed significantly higher positive connectivity with right angular gyrus (AG) and greater negative connectivity with right superior parietal gyrus (SPG) and right superior occipital gyrus (SOG), which were associated with the severity of symptoms in social interaction, communication and self-care ability. We suggest that stronger functional connectivity between left PCG and right AG, SPG, and SOG detected in young boys with ASD may serve as important indicators of disease severity. Our study provided preliminary functional evidence that may underlie impaired higher-order multisensory integration in ASD children.

Highlights

Autism spectrum disorder (ASD) is characterized by deficits in social communication, social interaction, and restricted, repetitive patterns of behavior, interests, or activities as defined in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) (American Psychiatric Association, 2013)
Behavioral Correlations with gray matter volume (GMV) Changes To examine the relationship between brain structural alterations and core symptoms of ASD children, correlations were calculated between scores on the Autism Diagnostic Observation Schedule (ADOS), Autism Diagnostic Interview-Revised (ADI-R) and Autism Behavior Checklist (ABC) and the volumetric data of the brain regions which showed group differences
Analyses revealed that there was no significant correlation between GMV of the left superior temporal gyrus (STG) and postcentral gyrus (PCG) and any of the ADOS, ADI-R and ABC scores, including the total and subscale scores

Summary

Introduction

Autism spectrum disorder (ASD) is characterized by deficits in social communication, social interaction, and restricted, repetitive patterns of behavior, interests, or activities as defined in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) (American Psychiatric Association, 2013). The prevalence of ASD seems to be increasing with time around the world. According to the Centers for Disease Control and Prevention (CDC) report, ASD affected nearly 1 in 68 children in the United States in 2012 (CDC, 2016). This estimate is significantly higher than the estimate of 1 in 152 children in 2002 (CDC, 2007). There is no doubt that the number of ASD patients is growing rapidly, which is accompanied by a huge burden on the caregivers as well as the whole society

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