Laboratory of Neuro Imaging at USC Stevens Neuroimaging and Informatics Institute, Keck School of Medicine of USC, University of Southern California, 2025 Zonal Ave, Los Angeles, CA 90033, USA.
Center for the Developing Brain, Child Mind Institute, New York, NY 10022, USA.
Cereb Cortex. 2020 Nov 3;30(12):6238-6253. doi: 10.1093/cercor/bhaa181.
Perinatal brain injuries in preterm neonates are associated with alterations in structural neurodevelopment, leading to impaired cognition, motor coordination, and behavior. However, it remains unknown how such injuries affect postnatal cortical folding and structural covariance networks, which indicate functional parcellation and reciprocal brain connectivity. Studying 229 magnetic resonance scans from 158 preterm neonates (n = 158, mean age = 28.2), we found that severe injuries including intraventricular hemorrhage, periventricular leukomalacia, and ventriculomegaly lead to significantly reduced cortical folding and increased covariance (hyper-covariance) in only the early (<31 weeks) but not middle (31-35 weeks) or late stage (>35 weeks) of the third trimester. The aberrant hyper-covariance may drive acceleration of cortical folding as a compensatory mechanism to "catch-up" with normal development. By 40 weeks, preterm neonates with/without severe brain injuries exhibited no difference in cortical folding and covariance compared with healthy term neonates. However, graph theory-based analysis showed that even after recovery, severely injured brains exhibit a more segregated, less integrated, and overall inefficient network system with reduced integration strength in the dorsal attention, frontoparietal, limbic, and visual network systems. Ultimately, severe perinatal injuries cause network-level deviations that persist until the late stage of the third trimester and may contribute to neurofunctional impairment.
早产儿围产期脑损伤与结构神经发育改变有关，导致认知、运动协调和行为受损。然而，目前尚不清楚这些损伤如何影响产后皮质折叠和结构协变网络，而这些网络则表明功能分区和大脑的相互连通性。本研究对 158 名早产儿的 229 次磁共振扫描（n=158，平均年龄=28.2）进行了研究，我们发现严重的损伤，包括脑室周围出血、脑室周围白质软化和脑室扩大，仅在第三孕期的早期（<31 周）而不是中期（31-35 周）或晚期（>35 周）导致皮质折叠减少和协变（超协变）增加。异常的超协变可能是一种代偿机制，以“追赶”正常发育，从而加速皮质折叠。到 40 周时，有/无严重脑损伤的早产儿与健康足月产儿相比，皮质折叠和协变没有差异。然而，基于图论的分析表明，即使在恢复后，严重受损的大脑仍然表现出更离散、更不集成、整体效率更低的网络系统，其背侧注意、额顶叶、边缘和视觉网络系统的整合强度降低。最终，严重的围产期损伤导致网络层面的偏差，这种偏差一直持续到第三孕期的晚期，可能导致神经功能障碍。
