Preterm birth poses a risk for neurocognitive and behavioral development. Preterm children, who have not been diagnosed with neurological or cognitive deficits, enter normal schools and are expected to succeed as their term-born peers. Here we tested the hypotheses that despite an uneventful development after preterm birth, these children might exhibit subtle abnormalities in brain function and white-matter microstructure at school-age. We recruited 7.5-year-old children born extremely prematurely (<28 weeks' gestation), and age- and gender-matched term-born controls (≥37 weeks' gestation). We applied fMRI during working-memory (WM) tasks, and investigated white-matter microstructure with diffusion tensor imaging. Compared with controls, preterm-born children performed WM tasks less accurately, had reduced activation in several right prefrontal areas, and weaker deactivation of right temporal lobe areas. The weaker prefrontal activation correlated with poorer WM performance. Preterm-born children had higher fractional anisotropy (FA) and lower diffusivity than controls in several white-matter areas, and in the posterior cerebellum, the higher FA associated with poorer visuospatial test scores. In controls, higher FA and lower diffusivity correlated with faster WM performance. Together these findings demonstrate weaker WM-related brain activations and altered white matter microstructure in children born extremely preterm, who had normal global cognitive ability.

中文翻译：

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学龄前极早产儿与工作记忆有关的大脑反应和白质微观结构发生改变。

早产会造成神经认知和行为发展的风险。尚未被诊断出神经或认知功能缺陷的早产儿进入正规学校就读，有望像他们的足月同龄人一样成功。在这里，我们检验了以下假设：尽管早产后发育平稳，但这些孩子在学龄期可能会表现出脑功能和白质微观结构的细微异常。我们招募了7.5岁的极早出生的孩子（小于28周的妊娠），以及年龄和性别匹配的足月对照（≥37周的妊娠）。我们在工作记忆（WM）任务中应用了功能磁共振成像，并通过扩散张量成像研究了白质微观结构。与对照组相比，早产儿执行WM任务的准确性较差，已降低了几个右前额叶区域的激活，并减弱了右颞叶区域的激活。较弱的前额叶激活与较差的WM性能相关。早产儿在几个白质区域的分数各向异性（FA）较高，扩散率较低，在小脑后部，较高的FA与较差的视觉空间测试分数相关。在对照中，较高的FA和较低的扩散率与更快的WM性能相关。这些发现共同表明，具有正常的全球认知能力的极早出生的儿童，与WM相关的脑部激活较弱，白质微观结构改变。早产儿在几个白质区域的分数各向异性（FA）较高，扩散率较低，在小脑后部，较高的FA与较差的视觉空间测试分数相关。在对照中，较高的FA和较低的扩散率与更快的WM性能相关。这些发现共同表明，具有正常的全球认知能力的极早出生的儿童，与WM相关的大脑激活较弱，白质微观结构改变。早产儿在几个白质区域的分数各向异性（FA）较高，扩散率较低，在小脑后部，较高的FA与较差的视觉空间测试分数相关。在对照中，较高的FA和较低的扩散率与更快的WM性能相关。这些发现共同表明，具有正常的全球认知能力的极早出生的儿童，与WM相关的大脑激活较弱，白质微观结构改变。