Department of Psychology, Yale University, New Haven, Connecticut.
Child Study Center, Yale University School of Medicine, New Haven, Connecticut.
Biol Psychiatry Cogn Neurosci Neuroimaging. 2020 May;5(5):490-498. doi: 10.1016/j.bpsc.2019.12.018. Epub 2020 Jan 13.
Childhood aggression has been linked to white matter abnormalities, but research has been inconsistent with regard to both regions of alterations and directionality of the associations. We examined white matter microstructure correlates of aggression using a novel diffusion imaging analysis technique, fixel-based analysis, which leverages connectivity and crossing-fiber information to assess fiber bundle density.
The sample included 70 children with aggressive behavior and 25 healthy control children without aggressive behavior. Aggression was measured by the parent-rated Aggressive Behavior scale of the Child Behavior Checklist. Fixel-based analysis was conducted at the whole-brain and region-of-interest levels, including the uncinate fasciculus, inferior longitudinal fasciculus, fornix, cingulum bundle, and genu, body, isthmus, and splenium of the corpus callosum.
Whole-brain analysis of covariance revealed that children with aggressive behavior, relative to control children, had lower fiber density in a cluster of limbic and cortical pathways, including the inferior fronto-occipital fasciculus, fornix, middle cerebellar peduncle, and superior thalamic radiations (familywise error-corrected p < .01), and had higher fiber density in the corpus callosum (body and splenium) (familywise error-corrected p < .05). Region-of-interest analyses showed decreased fiber density in cingulum bundles associated with aggression. These effects were independent of age, sex, IQ, symptoms of attention-deficit/hyperactivity disorder, medications, and head motion. In children with aggressive behavior, co-occurring callous-unemotional traits and anxiety did not moderate the association between aggression and white matter density.
Diminished white matter density in pathways connecting limbic and cortical regions is associated with childhood aggression. Abnormal interhemispheric connectivity via corpus callosum may also reflect a potential neural mechanism involved in aggression.
儿童时期的攻击行为与白质异常有关，但关于改变的区域和关联的方向性，研究结果并不一致。我们使用一种新的弥散成像分析技术——纤维束分析，检查了与攻击行为相关的白质微观结构。纤维束分析利用连接和穿越纤维信息来评估纤维束密度。
该样本包括 70 名具有攻击性行为的儿童和 25 名无攻击性行为的健康对照儿童。攻击性通过父母评定的《儿童行为检查表》中的攻击性行为量表进行测量。在全脑和感兴趣区域水平上进行纤维束分析，包括钩束、下纵束、穹窿、扣带束和胼胝体膝部、体部、干部、峡部和压部。
协方差全脑分析显示，与对照组儿童相比，具有攻击性行为的儿童在包括下额枕束、穹窿、小脑中脑脚、丘脑上辐射在内的边缘和皮质通路簇中纤维密度较低（校正后的家族性错误率 p < 0.01），胼胝体（体部和压部）纤维密度较高（校正后的家族性错误率 p < 0.05）。感兴趣区域分析显示，扣带束与攻击行为相关的纤维密度降低。这些影响独立于年龄、性别、智商、注意缺陷多动障碍症状、药物和头部运动。在具有攻击性行为的儿童中，冷酷无情特质和焦虑共病并不调节攻击行为与白质密度之间的关系。
连接边缘和皮质区域的通路中的白质密度降低与儿童期攻击行为有关。通过胼胝体的异常半球间连接也可能反映出与攻击行为有关的潜在神经机制。
