Neuroanatomical Diversity of Corpus Callosum and Brain Volume in Autism: Meta-analysis, Analysis of the Autism Brain Imaging Data Exchange Project, and Simulation
Neuroanatomical Diversity of Corpus Callosum and Brain Volume in Autism: Meta-analysis, Analysis of the Autism Brain Imaging Data Exchange Project, and Simulation
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DOI：
10.1016/j.biopsych.2015.02.010
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发表时间：
2015-07-15
影响因子：
10.6
通讯作者：
Toro, Roberto
中科院分区：
文献类型：
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作者：
Lefebvre, Aline;Beggiato, Anita;Toro, Roberto
背景：据报道，自闭症患者的胼胝体 (CC) 比对照组小。方法：我们对文献进行了荟萃分析，分析了自闭症脑成像数据交换项目的 694 名受试者的 CC，并进行计算机模拟以研究不同分析策略的效果。结果：我们的荟萃分析表明 CC 大小存在组间差异；然而，这些研究的功效严重不足（检测科恩 d = 0.3 的功效为 20%）。相比之下，尽管自闭症脑成像数据交换组的功效达到了 99%，但我们并没有观察到显着差异。然而，我们观察到 CC 与大脑体积 (BV) 呈非线性关系：大脑越大，CC 的比例就越小。我们的模拟表明，由于这种非线性，CC 归一化无法控制最终的 BV 差异，但使用 BV 作为线性模型中的协变量可以。我们还观察到，与对照组相比，病例中 IQ 和 BV 的相关性较弱。我们的模拟表明，通过智商匹配人群可能会导致人为的 BV 差异。结论：之前文献中缺乏统计能力，使我们无法确定自闭症中较小 CC 的说法的真实性，而我们自己的分析也没有发现任何差异。然而，CC 和 BV 之间的非线性关系以及病例和对照受试者中 BV 和 IQ 之间的不同相关性可能会引起人为差异。总的来说，我们的结果强调了开放数据共享的必要性，以便为在广泛的人类神经解剖多样性的背景下发现神经影像生物标志物提供更坚实的基础。
BACKGROUND: Patients with autism have been often reported to have a smaller corpus callosum (CC) than control subjects.METHODS: We conducted a meta-analysis of the literature, analyzed the CC in 694 subjects of the Autism Brain Imaging Data Exchange project, and performed computer simulations to study the effect of different analysis strategies.RESULTS: Our meta-analysis suggested a group difference in CC size; however, the studies were heavily underpowered (20% power to detect Cohen's d = .3). In contrast, we did not observe significant differences in the Autism Brain Imaging Data Exchange cohort, despite having achieved 99% power. However, we observed that CC scaled nonlinearly with brain volume (BV): large brains had a proportionally smaller CC. Our simulations showed that because of this nonlinearity, CC normalization could not control for eventual BV differences, but using BV as a covariate in a linear model would. We also observed a weaker correlation of IQ and BV in cases compared with control subjects. Our simulations showed that matching populations by IQ could then induce artifactual BV differences.CONCLUSIONS: The lack of statistical power in the previous literature prevents us from establishing the reality of the claims of a smaller CC in autism, and our own analyses did not find any. However, the nonlinear relationship between CC and BV and the different correlation between BV and IQ in cases and control subjects may induce artifactual differences. Overall, our results highlight the necessity for open data sharing to provide a more solid ground for the discovery of neuroimaging biomarkers within the context of the wide human neuroanatomical diversity.