Advances in Brain & Child Development (ABCD) Research Laboratory, Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
Department of Neurology & Neurosurgery, Faculty of Medicine & Health Sciences, McGill University, Montreal, Quebec, Canada.
Brain Behav. 2023 Dec;13(12):e3308. doi: 10.1002/brb3.3308. Epub 2023 Nov 23.
Executive function deficits and adverse psychological outcomes are common in youth with congenital heart disease (CHD) or born preterm. Association white matter bundles play a critical role in higher order cognitive and emotional functions and alterations to their microstructural organization may result in adverse neuropsychological functioning. This study aimed to examine the relationship of myelination and axon density and orientation alterations within association bundles with executive functioning, psychosocial well-being, and resilience in youth with CHD or born preterm.
Youth aged 16 to 26 years born with complex CHD or preterm at ≤33 weeks of gestational age and healthy controls completed a brain MRI and self-report assessments of executive functioning, psychosocial well-being, and resilience. Multicomponent driven equilibrium single-pulse observation of T and T and neurite orientation dispersion and density imaging were used to calculate average myelin water fraction (MWF), neurite density index (NDI), and orientation dispersion index values for eight bilateral association bundles. The relationships of bundle-average metrics with neuropsychological outcomes were explored with linear regression and mediation analyses.
In the CHD group, lower MWF in several bundles was associated with poorer working memory and behavioral self-monitoring and mediated self-monitoring deficits relative to controls. In the preterm group, lower NDI in several bundles was associated with poorer emotional control and lower MWF in the left superior longitudinal fasciculus III mediated planning/organizing deficits relative to controls. No significant relationships were observed for psychosocial well-being or resilience.
The findings of this study suggest that microstructural alterations to association bundles, including lower myelination and axon density, have different relationships with executive functioning in youth with CHD and youth born preterm. Future studies should aim to characterize other neurobiological, social, and environmental influences that may interact with white matter microstructure and neuropsychological functioning in these at-risk individuals.
执行功能缺陷和不良心理结果在患有先天性心脏病 (CHD) 或早产儿的年轻人中很常见。联合白质束在高级认知和情感功能中起着至关重要的作用，其微观结构组织的改变可能导致不良的神经心理功能。本研究旨在探讨联合束内髓鞘形成和轴突密度和方向改变与执行功能、心理社会健康和弹性的关系，以患有 CHD 或早产儿的年轻人为研究对象。
年龄在 16 至 26 岁之间的青少年，患有复杂的 CHD 或在妊娠 33 周前出生的早产儿，以及健康对照组，完成了脑 MRI 和执行功能、心理社会健康和弹性的自我报告评估。多组分驱动平衡单脉冲观察 T1 和 T2 以及神经丝取向弥散和密度成像，用于计算 8 对双侧联合束的平均髓鞘水分数 (MWF)、神经丝密度指数 (NDI) 和取向弥散指数值。采用线性回归和中介分析探讨束平均指标与神经心理学结果的关系。
在 CHD 组中，几个束中的 MWF 较低与工作记忆和行为自我监测较差有关，与对照组相比，自我监测缺陷存在中介作用。在早产儿组中，几个束中的 NDI 较低与情绪控制较差以及左优势纵向束 III 的 MWF 较低有关，与对照组相比，计划/组织缺陷存在中介作用。未观察到心理社会健康或弹性的显著关系。
本研究的结果表明，联合束的微观结构改变，包括髓鞘形成和轴突密度降低，与 CHD 青少年和早产儿青少年的执行功能有不同的关系。未来的研究应旨在描述其他神经生物学、社会和环境因素，这些因素可能与这些高危人群的白质微观结构和神经心理功能相互作用。
