Vollmer Brigitte, Lundequist Aiko, Mårtensson Gustaf, Nagy Zoltan, Lagercrantz Hugo, Smedler Ann-Charlotte, Forssberg Hans
Neuropaediatrics, Department of Women's and Children's Health, Karolinska Institutet, Astrid Lindgren Children's Hospital, Stockholm, Sweden.
Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.
PLoS One. 2017 Jun 8;12(6):e0178893. doi: 10.1371/journal.pone.0178893. eCollection 2017.
Executive functions are frequently a weakness in children born preterm. We examined associations of executive functions and general cognitive abilities with brain structure in preterm born adolescents who were born with appropriate weight for gestational age and who have no radiological signs of preterm brain injury on neuroimaging.
The Stockholm Neonatal Project (SNP) is a longitudinal, population-based study of children born preterm (<36 weeks of gestation) with very low birth weight (<1501g) between 1988-1993. At age 18 years (mean 18 years, SD 2 weeks) 134 preterm born and 94 full term participants underwent psychological assessment (general intelligence, executive function measures). Of these, 71 preterm and 63 full term participants underwent Magnetic Resonance Imaging (MRI) at mean 15.2 years (range 12-18 years), including 3D T1-weighted images for volumetric analyses and Diffusion Tensor Imaging (DTI) for assessment of white matter microstructure. Group comparisons of regional grey and white matter volumes and fractional anisotropy (FA, as a measure of white matter microstructure) and, within each group, correlation analyses of cognitive measures with MRI metrics were carried out.
Significant differences in grey and white matter regional volumes and widespread differences in FA were seen between the two groups. No significant correlations were found between cognitive measures and brain volumes in any group after correction for multiple comparisons. However, there were significant correlations between FA in projection fibres and long association fibres, linking frontal, temporal, parietal, and occipital lobes, and measures of executive function and general cognitive abilities in the preterm born adolescents, but not in the term born adolescents.
In persons born preterm, in the absence of perinatal brain injury on visual inspection of MRI, widespread alterations in regional brain tissue volumes and microstructure are present in adolescence/young adulthood. Importantly, these alterations in WM tracts are correlated with measures of executive function and general cognitive abilities. Our findings suggest that disturbance of neural pathways, rather than changes in regional brain volumes, are involved in the impaired cognitive functions.
执行功能在早产出生的儿童中常常较为薄弱。我们研究了在出生时体重适合胎龄且神经影像学检查无早产脑损伤放射学迹象的早产青少年中，执行功能和一般认知能力与脑结构之间的关联。
斯德哥尔摩新生儿项目（SNP）是一项基于人群的纵向研究，研究对象为1988年至1993年间早产（孕周<36周）且出生体重极低（<1501克）的儿童。在18岁时（平均18岁，标准差2周），134名早产出生的参与者和94名足月出生的参与者接受了心理评估（一般智力、执行功能测量）。其中，71名早产参与者和63名足月参与者在平均15.2岁（范围12 - 18岁）时接受了磁共振成像（MRI）检查，包括用于体积分析的3D T1加权图像和用于评估白质微观结构的扩散张量成像（DTI）。对两组之间区域灰质和白质体积以及分数各向异性（FA，作为白质微观结构的一种测量指标）进行了组间比较，并在每组内进行了认知测量与MRI指标的相关性分析。
两组之间灰质和白质区域体积存在显著差异，FA也存在广泛差异。在进行多重比较校正后，任何一组中认知测量与脑体积之间均未发现显著相关性。然而，在早产青少年中，连接额叶、颞叶、顶叶和枕叶的投射纤维和长联合纤维中的FA与执行功能测量和一般认知能力之间存在显著相关性，而足月出生的青少年中则不存在这种相关性。
在早产出生的人群中，在MRI视觉检查未发现围产期脑损伤的情况下，青春期/青年期存在区域脑组织体积和微观结构的广泛改变。重要的是，这些白质束的改变与执行功能测量和一般认知能力相关。我们的研究结果表明，神经通路的紊乱而非区域脑体积的变化与认知功能受损有关。
