BRAIN DEVELPMENT IN AUTISM

我们实验室以前的工作表明，与年龄匹配的发育迟缓（DD）和典型发育（ID）儿童相比，患有自闭症谱系障碍（ASD）的3-4岁儿童具有大脑扩大，以及皮层下区域（小脑，小脑和杏仁核）的比例扩大。患有严格定义的自闭症（AD）的儿童表现出杏仁核的扩大，超过了整个大脑的扩大。从同一组儿童，质子回波平面光谱成像（PEPSI）显示广泛的区域减少，脑神经化学物质的浓度和异常代谢物松弛的ASD儿童相对于对照组，表明异常的细胞组成。这些发现表明，自闭症患者在3-4岁时大脑发育过程异常。 在拟议的STAART中心研究中，我们的目标是通过在目前有可能诊断这种疾病的最早年龄对AD儿童进行脑成像研究，来增加我们对早期大脑发育异常的理解。我们建议对48名18-24个月大的AD儿童和25名DD和TD儿童进行脑结构和基于组织的神经化学表征。在AD组中，我们将在18-24个月时进行的大脑结构和化学研究结果与在18-24个月时以及随后在4岁时进行的神经认知和症状测量相关联。 此外，基于从出生到18-24个月回顾性获得的头围的重复测量，以及从18-24个月到4岁的前瞻性测量，将检查自闭症患者头部生长的早期发育过程。

Previous work in our laboratory demonstrated that 3-4 year-old children with autism spectrum disorder (ASD) have cerebral enlargement, as well as proportional enlargement of subcortical regions (cerebellum, hippocampi and amygdalae), compared to age-matched children with developmental delay (DD) and typical development (ID). Children with strictly defined autistic disorder (AD) showed enlargement of the amygdalae, in excess of overall cerebral enlargement. From the same groups of children, proton echoplanar spectroscopic imaging (PEPSI) revealed widespread regional decreases in brain neurochemical concentrations and abnormal metabolite relaxation in the ASD children relative to controls, indicative of abnormal celluiar composition. These findings demonstrate abnormal brain developmental processes in autism by 3-4 years of age. In the proposed STAART Center research, we aim to increase our understanding of abnormalities in early brain development by conducting brain imaging research with children with AD at the earliest age it is currently possible to diagnose this disorder. We propose to characterize brain structure and tissue-based neurochemistry in forty-eight 18-24 month-old children with AD and matched comparison groups of 25 children with DD and TD. In the AD group, we will relate brain structural and chemical findings taken at 18-24 months to neurocognitive and symptom measures taken at 18-24 months and later at 4 years of age. Furthermore, based on repeated measures of head circumference obtained retrospectively from birth to 18-24 months, and prospectively from 18-24 month to 4 years, the early developmental course of head growth in autism will be examined.