Center for Interdisciplinary Brain Sciences Research, Department of Psychiatry and Behavioral Sciences, Stanford, United States.
Prog Neuropsychopharmacol Biol Psychiatry. 2014 Jan 3;48:124-8. doi: 10.1016/j.pnpbp.2013.09.010. Epub 2013 Sep 25.
Previous studies suggest that amygdala volume, when compared with healthy controls, is increased in young children with autism, is unchanged in cohorts of older youth, and is smaller in adults. Hippocampal volume, however, does not appear to have age-related changes, and it is unclear whether individuals with autism have volumetric differences in this structure. The goal of this pilot investigation is to characterize the developmental trajectories of the amygdala and hippocampus in children with autism between the ages of 8 and 14years and to examine clinical correlates of volume change.
Twenty-three children with autism and 23 controls between the ages of 8 and 12 underwent a magnetic resonance imaging procedure of the brain (T1-weighted) at two time points. Nine children with autism and 14 controls had good quality scans from both time points; however, all usable scans from all subjects (15 children with autism and 22 controls) were included in a mixed effect analysis. Regression models were used to estimate group differences in amygdala and hippocampal volumes. Changes in amygdala and hippocampal volumes (Time 2-Time 1) were correlated with clinical severity measures.
Amygdala volume changes with time were similar between the two groups. Within the autism group, right amygdala volume change was correlated with the ability to establish appropriate eye contact. Right hippocampal volume was significantly increased in the autism group when compared with controls. Differences in right hippocampal volume change with time between the two groups approached significance.
This study provides preliminary evidence of normalization of amygdala volumes in late childhood and adolescence. It also suggests that hippocampal volumetric differences may exist in autism in late childhood and adolescence.
先前的研究表明，与健康对照组相比，自闭症儿童的杏仁核体积在幼儿时期增加，在年龄较大的青少年时期不变，而在成年期则较小。然而，海马体体积似乎没有与年龄相关的变化，目前尚不清楚自闭症患者在该结构中是否存在体积差异。本研究旨在描述 8 至 14 岁自闭症儿童的杏仁核和海马体的发育轨迹，并研究体积变化的临床相关性。
23 名自闭症儿童和 23 名年龄在 8 至 12 岁之间的对照组接受了两次脑磁共振成像（T1 加权）。9 名自闭症儿童和 14 名对照组有两次时间点的高质量扫描；然而，所有可用的扫描（15 名自闭症儿童和 22 名对照组）都被纳入混合效应分析。回归模型用于估计杏仁核和海马体体积的组间差异。杏仁核和海马体体积（时间 2-时间 1）的变化与临床严重程度测量相关。
两组之间杏仁核体积随时间的变化相似。在自闭症组中，右侧杏仁核体积的变化与建立适当眼神接触的能力相关。与对照组相比，自闭症组的右侧海马体体积明显增加。两组之间右侧海马体体积随时间的变化差异接近显著。
本研究提供了初步证据表明杏仁核体积在儿童晚期和青春期趋于正常。它还表明，在儿童晚期和青春期，自闭症患者可能存在海马体体积差异。
