Cerebral lobes in autism: Early hyperplasia and abnormal age effects
Cerebral lobes in autism: Early hyperplasia and abnormal age effects
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DOI：
10.1006/nimg.2002.1099
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发表时间：
2002-08-01
期刊：
影响因子：
5.7
通讯作者：
Courchesne, E
中科院分区：
文献类型：
--
作者：
Carper, RA;Moses, P;Courchesne, E
代谢、功能、行为和组织学研究表明，自闭症患者的大脑结构可能异常。在先前的一项横断面研究中，我们发现2岁和3岁的自闭症儿童大脑皮层和脑白质体积异常增大，且在随后的年龄段中体积变化速度异常缓慢。在本研究中，我们评估了这些体积异常是局限于特定的大脑区域，还是普遍存在于整个大脑。我们使用磁共振成像（MRI）来量化大脑叶（额叶、颞叶、顶叶和枕叶区域）的体积，利用经典的脑沟边界来界定区域。我们对38名2至11岁的自闭症男孩和39名正常对照男孩进行了检查。几个区域在2岁和3岁的患者中显示出灰质和白质增生的迹象（增大多达20%），但增生程度似乎存在从前到后的梯度。额叶增大最明显，而枕叶与正常无显著差异。在年龄较大的儿童中未发现灰质和白质的差异。通过检查区域体积与受试者年龄之间的关系，我们发现，在2至11岁的年龄范围内，自闭症患者的额叶、颞叶和顶叶白质体积以及额叶和颞叶灰质体积的变化速度明显比对照组慢。例如，从2 - 4岁到9 - 11.5岁，额叶白质体积增加了约45%，但在自闭症患者中仅增加了13%。我们讨论了可能导致早期增生的机制，因为它们可能与异常程度的区域差异有关。例如，考虑了神经营养因子的可能影响，或来自其他受影响脑区的异常传入活动的影响。（C）2002爱思唯尔科学（美国）
Metabolic, functional, behavioral, and histologic studies suggest that the structure of the cerebrum may be abnormal in autism. In a previous cross-sectional study we found abnormal enlargement of cerebral cortex and cerebral white matter volumes in autistic 2 and 3 year olds and abnormally slow rates of volume change across later ages. In the present study, we assessed whether these volume abnormalities are limited to particular cerebral regions or are pervasive throughout the: cerebrum. We used magnetic resonance imaging (MRI) to quantify volumes of cerebral lobes (frontal, temporal, parietal, and occipital regions), using Classic sulcal boundaries to define regions. We examined 38 boys with autism and 39 normal control boys between the ages of 2 and 11 years. Several regions, showed signs of gray matter and white matter hyperplasia in 2- and 3-year-old patients (as much as 20% enlargement), but there appeared to be an anterior to posterior gradient in the degree of hyperplasia. The frontal lobe showed the greatest enlargement while the occipital lobe was not significantly different from normal. Gray and white matter differences were not found in the older children. By examining the relationships between regional volumes and subject age, we found that frontal, temporal, and parietal white matter volumes, as well as frontal and temporal gray matter volumes, changed at significantly slower rates in autism patients than in controls across the 2- to 11-year-age range. For example, frontal lobe white matter volume increased by about 45% from 2-4 years of age to 9-11.5 years, but by only 13% in autistic patients. Mechanisms that might account for early hyperplasia are discussed as they might relate to the regional differences in degree of abnormality. For instance, possible influences of neurotrophic factors, or of abnormal afferent activity from other affected brain regions are considered. (C) 2002 Elsevier Science (USA).