Faculty of Child and Maternal Health, School of Public Health, Sun Yat-sen University, Guangzhou, Guangdong 510080, China.
Chin Med J (Engl). 2011 May;124(9):1362-6.
Autism spectrum disorders (ASD), which include autism, asperger syndrome (AS) and pervasive developmental disorder-not otherwise specified (PDD-NOS), are devastating neurodevelopmental disorders of childhood resulting in deficits in social interaction, repetitive patterns of behaviors, and restricted interests and activities. Single photon emission computed tomography (SPECT) is a common technique used to measure regional cerebral blood flow (rCBF). Several studies have measured rCBF in children with ASD using SPECT, however, findings are discordant. In addition, the majority of subjects used in these studies were autistic. In this study, we aimed to investigate changes in rCBF in children with ASD using SPECT.
A Technetium-99m-ethyl cysteinate dimmer (⁹⁹m)Tc-ECD) brain SPECT study was performed on an ASD group consisting of 23 children (3 girls and 20 boys; mean age (7.2 ± 3.0) years) who were diagnosed according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) criteria and an age-matched control group with 8 children (1 girl and 7 boys, mean age (5.5 ± 2.4) years). Image data were evaluated with Statistical Parametric Mapping, 5th version (SPM5). A Student's t test for unpaired data was used to compare rCBF and asymmetry in the autism and corresponding control group. The covariance analysis, taking age as covariance, was performed between the ASD and control group.
There was a significant reduction in rCBF in the bilateral frontal lobe (frontal poles, arcula frontal gyrus) and the bilateral basal ganglia in the autism group, and a reduction in the bilateral frontal, temporal, parietal, legumina nucleus and cerebellum in the AS group compared to the control. In addition, asymmetry of hemispheric hypoperfusion in the ASD group was observed. Inner-group comparison analysis revealed that rCBF decreased significantly in the bilateral frontal lobe (42.7%), basal nucleus (24.9%) and temporal lobe (22.8%) in the autism group, and in the bilateral cerebellum (22.8%), basal nucleus (19.3%) and right thalamencephalon (16.6%) in the AS group (P < 0.05).
The decrease in rCBF in ASD is a global event, which involves the bilateral frontal, temporal, limbic system and basal ganglias. Asymmetry of hemispheric hypoperfusion was more obvious in the AS group than the autism group, which indicates a different neurobiological mechanism from that of autism.
自闭症谱系障碍（ASD）包括自闭症、阿斯伯格综合征（AS）和广泛性发育障碍未特定型（PDD-NOS），是一种严重的儿童神经发育障碍，导致社交互动、行为重复模式以及兴趣和活动受限。单光子发射计算机断层扫描（SPECT）是一种常用的测量局部脑血流（rCBF）的技术。几项研究使用 SPECT 测量了 ASD 儿童的 rCBF，但结果不一致。此外，这些研究中的大多数受试者都是自闭症患者。在这项研究中，我们旨在使用 SPECT 研究 ASD 儿童的 rCBF 变化。
对 23 名儿童（3 名女孩和 20 名男孩；平均年龄（7.2 ± 3.0）岁）进行了锝-99m-乙基半胱氨酸二聚体（⁹⁹mTc-ECD）脑 SPECT 研究，这些儿童根据精神障碍诊断与统计手册，第 4 版（DSM-IV）标准诊断为 ASD，同时还有 8 名年龄匹配的对照组儿童（1 名女孩和 7 名男孩，平均年龄（5.5 ± 2.4）岁）。使用统计参数映射，第 5 版（SPM5）对图像数据进行评估。使用未配对数据的学生 t 检验比较自闭症组和相应对照组的 rCBF 和不对称性。对 ASD 组和对照组进行协方差分析，以年龄为协变量。
自闭症组双侧额叶（额极、额回）和双侧基底节区 rCBF 明显降低，AS 组双侧额叶、颞叶、顶叶、丘脑核和小脑 rCBF 降低。此外，在 ASD 组观察到半球低灌注的不对称性。组内比较分析显示，自闭症组双侧额叶（42.7%）、基底核（24.9%）和颞叶（22.8%）rCBF 显著降低，AS 组双侧小脑（22.8%）、基底核（19.3%）和右侧丘脑（16.6%）rCBF 降低（P < 0.05）。
ASD 中 rCBF 的降低是一个全局事件，涉及双侧额叶、颞叶、边缘系统和基底节。与自闭症组相比，AS 组半球低灌注的不对称性更为明显，表明其神经生物学机制与自闭症不同。
