BACKGROUND Premature birth is associated with high prevalence of neurodevelopmental impairments in surviving infants. The putative role of cerebellar and brainstem dysfunction remains poorly understood, particularly in the absence of overt structural injury. METHOD We compared in-utero versus ex-utero global, regional and local cerebellar and brainstem development in healthy fetuses (n = 38) and prematurely born infants without evidence of structural brain injury on conventional MRI studies (n = 74) that were performed at two time points: the first corresponding to the third trimester, either in utero or ex utero in the early postnatal period following preterm birth (30-40 weeks of gestation; 38 control fetuses; 52 premature infants) and the second at term equivalent age (37-46 weeks; 38 control infants; 58 premature infants). We compared 1) volumetric growth of 7 regions in the cerebellum (left and right hemispheres, left and right dentate nuclei, and the anterior, neo, and posterior vermis); 2) volumetric growth of 3 brainstem regions (midbrain, pons, and medulla); and 3) shape development in the cerebellum and brainstem using spherical harmonic description between the two groups. RESULTS Both premature and control groups showed regional cerebellar differences in growth rates, with the left and right cerebellar hemispheres showing faster growth compared to the vermis. In the brainstem, the pons grew faster than the midbrain and medulla in both prematurely born infants and controls. Using shape analyses, premature infants had smaller left and right cerebellar hemispheres but larger regional vermis and paravermis compared to in-utero control fetuses. For the brainstem, premature infants showed impaired growth of the superior surface of the midbrain, anterior surface of the pons, and inferior aspects of the medulla compared to the control fetuses. At term-equivalent age, premature infants had smaller cerebellar hemispheres bilaterally, extending to the superior aspect of the left cerebellar hemisphere, and larger anterior vermis and posteroinferior cerebellar lobes than healthy newborns. For the brainstem, large differences between premature infants and healthy newborns were found in the anterior surface of the pons. CONCLUSION This study analyzed both volumetric growth and shape development of the cerebellum and brainstem in premature infants compared to healthy fetuses using longitudinal MRI measurements. The findings in the present study suggested that preterm birth may alter global, regional and local development of the cerebellum and brainstem even in the absence of structural brain injury evident on conventional MRI.

中文翻译：

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早产儿局部小脑和脑干发育的改变

背景早产与幸存婴儿的神经发育障碍的高患病率相关。小脑和脑干功能障碍的假定作用仍然知之甚少，特别是在没有明显结构损伤的情况下。方法 我们比较了健康胎儿（n = 38）和没有结构性脑损伤证据的早产婴儿的子宫内与子宫外的整体、区域和局部小脑和脑干发育，这些婴儿在常规 MRI 研究（n = 74）中进行了两个时间点：第一个对应于孕晚期，在早产后的早期子宫内或子宫外（妊娠 30-40 周；38 个对照胎儿；52 个早产儿）和第二个在足月等效年龄（ 37-46 周；38 名对照婴儿；58 名早产儿）。我们比较了 1) 小脑 7 个区域（左右半球，左右齿状核，以及前、新、后蚓部）的体积生长；2) 3 个脑干区域（中脑、脑桥和髓质）的体积生长；3) 小脑和脑干的形状发育使用两组之间的球谐描述。结果 早产组和对照组均显示出区域性小脑的生长速度差异，与蚓部相比，左右小脑半球的生长速度更快。在脑干中，早产儿和对照组的脑桥比中脑和髓质生长得更快。使用形状分析，与宫内对照胎儿相比，早产儿的左右小脑半球较小，但局部蚓部和寄生虫较大。对于脑干，与对照胎儿相比，早产儿的中脑上表面、脑桥前表面和髓质下表面的生长受损。在足月等效年龄，与健康新生儿相比，早产儿双侧小脑半球较小，延伸至左小脑半球的上部，前蚓部和小脑后下叶较大。对于脑干，早产儿和健康新生儿的脑桥前表面存在很大差异。结论 本研究使用纵向 MRI 测量分析了与健康胎儿相比早产儿小脑和脑干的体积生长和形状发育。本研究的结果表明，早产可能会改变全球、