DeRamus Thomas P, Kana Rajesh K
Department of Psychology, University of Alabama, Birmingham, USA.
Neuroimage Clin. 2014 Nov 18;7:525-36. doi: 10.1016/j.nicl.2014.11.004. eCollection 2015.
Autism spectrum disorders (ASD) are characterized by impairments in social communication and restrictive, repetitive behaviors. While behavioral symptoms are well-documented, investigations into the neurobiological underpinnings of ASD have not resulted in firm biomarkers. Variability in findings across structural neuroimaging studies has contributed to difficulty in reliably characterizing the brain morphology of individuals with ASD. These inconsistencies may also arise from the heterogeneity of ASD, and wider age-range of participants included in MRI studies and in previous meta-analyses. To address this, the current study used coordinate-based anatomical likelihood estimation (ALE) analysis of 21 voxel-based morphometry (VBM) studies examining high-functioning individuals with ASD, resulting in a meta-analysis of 1055 participants (506 ASD, and 549 typically developing individuals). Results consisted of grey, white, and global differences in cortical matter between the groups. Modeled anatomical maps consisting of concentration, thickness, and volume metrics of grey and white matter revealed clusters suggesting age-related decreases in grey and white matter in parietal and inferior temporal regions of the brain in ASD, and age-related increases in grey matter in frontal and anterior-temporal regions. White matter alterations included fiber tracts thought to play key roles in information processing and sensory integration. Many current theories of pathobiology ASD suggest that the brains of individuals with ASD may have less-functional long-range (anterior-to-posterior) connections. Our findings of decreased cortical matter in parietal-temporal and occipital regions, and thickening in frontal cortices in older adults with ASD may entail altered cortical anatomy, and neurodevelopmental adaptations.
自闭症谱系障碍（ASD）的特征是社交沟通障碍以及局限、重复的行为。虽然行为症状有充分记录，但对ASD神经生物学基础的研究尚未得出确切的生物标志物。结构神经影像学研究结果的变异性导致难以可靠地描述ASD个体的脑形态。这些不一致也可能源于ASD的异质性，以及MRI研究和以往荟萃分析中纳入的参与者年龄范围更广。为了解决这个问题，本研究对21项基于体素的形态计量学（VBM）研究进行了基于坐标的解剖似然估计（ALE）分析，这些研究考察了高功能ASD个体，从而对1055名参与者（506名ASD患者和549名正常发育个体）进行了荟萃分析。结果包括两组之间灰质、白质和全脑皮质物质的差异。由灰质和白质的浓度、厚度和体积指标组成的模拟解剖图谱显示，聚类表明ASD患者大脑顶叶和颞下区域的灰质和白质与年龄相关的减少，以及额叶和颞前区域的灰质与年龄相关的增加。白质改变包括被认为在信息处理和感觉整合中起关键作用的纤维束。目前许多关于ASD病理生物学的理论认为，ASD个体的大脑可能具有功能较弱的长程（从前到后）连接。我们发现ASD老年患者顶颞和枕叶区域的皮质物质减少，额叶皮质增厚，这可能意味着皮质解剖结构改变和神经发育适应。
