Ass. La Nostra Famiglia, Pasian di Prato, Udine, Italy.
Brain Res Bull. 2011 Feb 1;84(2):189-95. doi: 10.1016/j.brainresbull.2010.12.002. Epub 2010 Dec 10.
A combined protocol of voxel-based morphometry (VBM) and diffusion-weighted imaging (DWI) was applied to investigate the neurodevelopment of gray and white matter in autism.
Twenty children with autism (mean age= 7 ± 2.75 years old; age range: 4-14; 2 girls) and 22 matched normally developing children (mean age = 7.68 ± 2.03 years old; age range: 4-11; 2 girls) underwent magnetic resonance imaging (MRI). VBM was employed by applying the Template-o-Matic toolbox (TOM), a new approach which constructs the age-matched customized template for tissue segmentation. Also, the apparent diffusion coefficients (ADC) of water molecules were obtained from the analysis of DWI. Regions of interests (ROIs), standardized at 5 pixels, were placed in cortical lobes and corpus callosum on the non-diffusion weighted echo-planar images (b = 0) and were then automatically transferred to the corresponding maps to obtain the ADC values.
Compared to normal children, individuals with autism had significantly: (1) increased white matter volumes in the right inferior frontal gyrus, the right fusiform gyrus, the left precentral and supplementary motor area and the left hippocampus, (2) increased gray matter volumes in the inferior temporal gyri bilaterally, the right inferior parietal cortex, the right superior occipital lobe and the left superior parietal lobule, and (3) decreased gray matter volumes in the right inferior frontal gyrus and the left supplementary motor area. Abnormally increased ADC values in the bilateral frontal cortex and in the left side of the genu of the corpus callosum were also reported in autism. Finally, age correlated negatively with lobar and callosal ADC measurements in individuals with autism, but not in children with normal development.
These findings suggest cerebral dysconnectivity in the early phases of autism coupled with an altered white matter maturation trajectory during childhood potentially taking place in the frontal and parietal lobes, which may represent a neurodevelopmental marker of the disorder, possibly accounting for the cognitive and social deficits.
本研究采用基于体素的形态学（VBM）和弥散加权成像（DWI）相结合的方法，探讨孤独症患者脑灰白质的神经发育情况。
20 名孤独症儿童（平均年龄=7±2.75 岁；年龄范围：4-14 岁；2 名女孩）和 22 名正常发育儿童（平均年龄=7.68±2.03 岁；年龄范围：4-11 岁；2 名女孩）接受了磁共振成像（MRI）检查。VBM 通过使用模板自动构建组织分割的年龄匹配自定义模板的新方法（Template-o-Matic toolbox，TOM）进行分析。此外，还从弥散加权成像（DWI）分析中获得水分子的表观扩散系数（ADC）。在无弥散加权回波平面图像（b=0）上，将标准化为 5 个像素的感兴趣区域（ROIs）置于皮质叶和胼胝体上，然后自动将其转移到相应的图谱中以获得 ADC 值。
与正常儿童相比，孤独症患者的右侧额下回、右侧梭状回、左侧中央前回和辅助运动区以及左侧海马的白质体积显著增加；双侧颞下回、右侧顶下小叶、右侧顶叶上叶和左侧顶叶上小叶的灰质体积增加；右侧额下回和左侧辅助运动区的灰质体积减少。孤独症患者双侧额叶和胼胝体膝部也存在 ADC 值异常增高。此外，孤独症患者的脑区 ADC 值与年龄呈负相关，但正常发育儿童的脑区 ADC 值与年龄无相关性。
这些发现表明孤独症患者存在脑连接中断，并且在儿童期白质成熟轨迹发生改变，这可能发生在额叶和顶叶，这可能是该疾病的神经发育标志物，可能导致认知和社会缺陷。
