Abstract:
Autism is a neurodevelopmental disorder characterized by impairments in reciprocal social interaction, deficits in verbal and nonverbal communication, and a restricted repertoire of activities or interests. We performed a magnetic resonance imaging study to better define the neuropathology of autistic spectrum disorders. Here we report findings on the amygdala and the hippocampal formation. Borders of the amygdala, hippocampus, and cerebrum were defined, and their volumes were measured in male children (7.5-18.5 years of age) in four diagnostic groups: autism with mental retardation, autism without mental retardation, Asperger syndrome, and age-matched typically developing controls. Although there were no differences between groups in terms of total cerebral volume, children with autism (7.5-12.5 years of age) had larger right and left amygdala volumes than control children. There were no differences in amygdala volume between the adolescent groups (12.75-18.5 years of age). Interestingly, the amygdala in typically developing children increases substantially in volume from 7.5 to 18.5 years of age. Thus, the amygdala in children with autism is initially larger, but does not undergo the age-related increase observed in typically developing children. Children with autism, with and without mental retardation, also had a larger right hippocampal volume than typically developing controls, even after controlling for total cerebral volume. Children with autism but without mental retardation also had a larger left hippocampal volume relative to controls. These cross-sectional findings indicate an abnormal program of early amygdala development in autism and an abnormal pattern of hippocampal development that persists through adolescence. The cause of amygdala and hippocampal abnormalities in autism is currently unknown.
摘要:
自闭症是一种神经发育障碍,其特征是相互的社交互动受损,语言和非语言交流的缺陷,以及有限的活动或兴趣。我们进行了磁共振成像研究,以更好地定义自闭症谱系障碍的神经病理学。在这里,我们报告了杏仁核和海马结构的发现。杏仁核的边界,海马体,和大脑被定义,在四个诊断组中测量了男性儿童(7.5-18.5岁)的体积:自闭症伴智力低下,没有智力障碍的自闭症,阿斯伯格综合症,和年龄匹配的典型发展控制。尽管两组之间在总脑容量方面没有差异,自闭症儿童(7.5~12.5岁)的左右杏仁核体积大于对照儿童.青少年组(12.75-18.5岁)之间的杏仁核体积没有差异。有趣的是,从7.5岁到18.5岁,通常发育中的儿童的杏仁核体积大大增加。因此,自闭症儿童的杏仁核最初较大,但没有经历典型发育儿童中观察到的与年龄相关的增加。自闭症儿童,有和没有智力障碍,右海马体积也比通常发育中的对照组大,即使在控制了大脑总容量之后.自闭症但没有智力障碍的儿童相对于对照组也有更大的左海马体积。这些横断面发现表明自闭症中杏仁核早期发育的异常程序和持续到青春期的海马发育异常模式。自闭症中杏仁核和海马异常的原因目前尚不清楚。