Regional age differences in gray matter diffusivity among healthy older adults.
Regional age differences in gray matter diffusivity among healthy older adults.
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健康老年人的灰质扩散率的区域年龄差异。
DOI：
10.1007/s11682-015-9383-7
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发表时间：
2016-03
影响因子：
3.2
通讯作者：
Paul RH
中科院分区：
文献类型：
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作者：
Salminen LE;Conturo TE;Laidlaw DH;Cabeen RP;Akbudak E;Lane EM;Heaps JM;Bolzenius JD;Baker LM;Cooley S;Scott S;Cagle LM;Phillips S;Paul RH
衰老与脑组织的微观结构变化有关，可以使用扩散张量成像（DTI）将其可视化。虽然之前的研究已经使用 DTI 确定了白质 (WM) 扩散与年龄相关的变化，但年龄对灰质 (GM) 扩散的影响仍不清楚。本研究利用平均扩散率 (MD) 的 DTI 指标来识别健康老年人 (N=60) 样本中 GM/WM 微观结构的年龄差异。第二个目的是使用神经心理状态评估可重复电池 (RBANS) 确定全脑 GM/WM MD 对整体认知功能的功能意义。参与者被分为三个年龄段（50-59 岁、60-69 岁和 70 岁以上），以检查不同十年之间 MD 和认知的差异。对额叶、颞叶、顶叶和枕叶的双侧 MD 进行了初步分析，并使用全脑 MD 的总体测量来测试与认知的关系。在老年人的颞叶和顶叶的双侧 GM 以及额叶和颞叶的右半球 WM 中观察到显着较高的 MD。 MD 的最大差异发生在 50-59 岁和 70 岁以上年龄组之间。在 60-69 岁年龄组中，较高的全脑 GM MD 与较差的 RBANS 表现相关。结果表明，衰老对健康老年人的 GM/WM 扩散具有显着且不同的影响，这可能解释了老年人在特定时间点存在一定程度的认知变异的原因。
Aging is associated with microstructural changes in brain tissue that can be visualized using diffusion tensor imaging (DTI). While previous studies have established age-related changes in white matter (WM) diffusion using DTI, the impact of age on gray matter (GM) diffusion remains unclear. The present study utilized DTI metrics of mean diffusivity (MD) to identify age differences in GM/WM micro-structure in a sample of healthy older adults (N=60). A secondary aim was to determine the functional significance of whole-brain GM/WM MD on global cognitive function using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Participants were divided into three age brackets (ages 50–59, 60–69, and 70+) to examine differences in MD and cognition by decade. MD was examined bilaterally in the frontal, temporal, parietal, and occipital lobes for the primary analyses and an aggregate measure of whole-brain MD was used to test relationships with cognition. Significantly higher MD was observed in bilateral GM of the temporal and parietal lobes, and in right hemisphere WM of the frontal and temporal lobes of older individuals. The most robust differences in MD were between the 50–59 and 70+ age groups. Higher whole-brain GM MD was associated with poorer RBANS performance in the 60–69 age group. Results suggest that aging has a significant and differential impact on GM/WM diffusion in healthy older adults, which may explain a modest degree of cognitive variability at specific time points during older adulthood.