MEGALENCEPHALY IN AUTISM

我们实验室和其他实验室的结果都表明，巨头症 在患有特发性自闭症的儿童和成人中存在14-26%。MRL 对大脑重量的研究和尸检表明 自闭症的巨头畸形是由于巨脑畸形增大所致。 大脑的一部分。我们实验室的结果表明，在自闭症患者中 没有选择头部大小的个人，大脑大小会因为 增加顶骨、颞骨和枕骨的体积(即， 后)叶。相对于总的脑体积，语体的大小 骨痂不成比例地减少。更多数据表明， 皮质增大以右侧为主。MR研究来自 其他中心支持这些发现的有效性。 神经心理学和神经生物学证据现在表明，自闭症 是一种复杂分布式神经网络的紊乱，导致 异常的大脑组织和连接。发现了…… 自闭症中的巨脑提示细胞的异常 细胞增殖或程序性细胞死亡也参与其中。整体而言 这个应用程序的目标是在我们以前在Structure中所做的工作的基础上 通过探索大脑大小和形状的异常来进行成像和遗传学 在患有巨脑的自闭症患者中，通过检查 这些异常在本病发病机制中的意义 无序。我们建议：1)检查异常增长模式和 患有巨脑症的自闭症患者的组织结构 由于(A)前后部关系的异常 皮质脑体积，(B)皮质和胼胝体大小，(C)灰色 和白质体积，以及，(D)右侧和左侧皮质叶 2)探索可能构成大脑基础的发育机制 自闭症患者头部变化轨迹的研究 周长超时；3)检查各证候的异质性 探索大脑大小和形状之间的关系的自闭症 自闭症相关临床特征的MRI异常 包括行为和神经心理特征。

Results from both our laboratory and others indicate that macrocephaly is present in 14-26% of children and adults with idiopathic autism. MRl studies and post mortem studies of brain weight suggest that macrocephaly in autism is due to megalencephaly, abnormal enlargement of the brain. Results from our laboratory indicate that in autistic individuals unselected for head size, brain size is increased due to increased volume of the parietal, temporal and occipital (i.e., posterior) lobes. Relative to total brain volume the size of the corpus callosum is disproportionately decreased. Additional data suggest that cortical enlargement is predominantly right-sided. MR studies from other centers support the validity of these findings.- Neuropsychological and neurobiological evidence now suggest that autism is a disorder of a complex distributed neural network resulting in anomalous brain organization and connectivity. The finding of megalencephaly in autism suggests that abnormalities of cellular proliferation or programmed cell death are also involved. The overall goal of this application is to build on our previous work in structural imaging and genetics by exploring abnormalities in brain size and shape in autistic individuals with megalencephaly and by examining the significance of these abnormalities for the pathogenesis of this disorder. We propose to: 1) examine anomalous patterns of growth and organization in autistic individuals with megalencephaly as evidenced by abnormalities in the relationship between (a) anterior and posterior cortical brain volume, (b) cortical and corpus callosum size, (c) gray and white matter volume, and, (d) right- and left-sided cortical lobe volumes; 2) explore developmental mechanisms that may underlie brain enlargement in autism by examining the trajectory of changes in head circumference overtime; 3) examine heterogeneity in the syndrome of autism by exploring the relationship between brain size and shape abnormalities on MRI to clinical features associated with autism including behavioral and neuropsychological characteristics.