Vanderbilt Memory and Alzheimer's Center, Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN, USA; Department of Neurology, Vanderbilt Genetics Institute, Vanderbilt University School of Medicine, Nashville, TN, USA.
Vanderbilt Memory and Alzheimer's Center, Department of Neurology, Vanderbilt University School of Medicine, Nashville, TN, USA.
Neurobiol Aging. 2020 Oct;94:15-23. doi: 10.1016/j.neurobiolaging.2020.05.001. Epub 2020 May 12.
Although hippocampal volume has served as a long-standing predictor of cognitive decline, diffusion magnetic resonance imaging studies of white matter have shown similar relationships. Still, it remains unclear if gray matter and white matter interact to predict cognitive impairment and longitudinal decline. Here, we investigate whether free-water (FW) and FW-corrected fractional anisotropy (FA) within medial temporal lobe white matter tracts provides meaningful contribution to cognition and cognitive decline beyond hippocampal volume. Using data from the Vanderbilt Memory & Aging Project (n = 319), we found that FW was associated with baseline memory and executive function beyond that of hippocampal volume and other comorbidities. Longitudinal analyses demonstrated significant interactions of hippocampal volume and inferior longitudinal fasciculus (p = 0.043) and cingulum bundle (p = 0.025) FA on memory decline and with fornix FA (p = 0.025) on decline in executive function. Results suggest that FW metrics of white matter have a unique role in cognitive decline and should be included in theoretical models of aging, cerebrovascular disease, and Alzheimer's disease.
虽然海马体体积一直是认知能力下降的长期预测指标，但磁共振弥散成像研究显示白质也存在类似的关系。然而，目前尚不清楚灰质和白质是否相互作用以预测认知障碍和纵向下降。在这里，我们研究了内侧颞叶白质束内的自由水 (FW) 和 FW 校正的各向异性分数 (FA) 是否除了海马体体积和其他合并症之外，对认知和认知下降有意义的贡献。我们使用范德比尔特记忆与衰老项目的数据（n=319）发现，FW 与基线记忆和执行功能有关，而不仅仅是海马体体积和其他合并症。纵向分析表明，海马体体积和下纵束（p=0.043）和扣带束（p=0.025）FA 对记忆下降存在显著的相互作用，而穹窿束 FA 与执行功能下降存在显著的相互作用（p=0.025）。结果表明，FW 白质指标在认知下降中具有独特的作用，应该被纳入衰老、血管性疾病和阿尔茨海默病的理论模型中。
