1VA San Diego Healthcare System,San Diego,California.
J Int Neuropsychol Soc. 2018 Mar;24(3):213-223. doi: 10.1017/S135561771700087X. Epub 2017 Oct 4.
Subjective cognitive decline (SCD), or self-reported cognitive decline despite normal neuropsychological test performance, is a risk factor for objective cognitive decline and Alzheimer's disease (AD). While brain mechanisms contributing to SCD are not well defined, studies show associations with vascular risk factors and altered cerebral blood flow (CBF), raising the hypothesis that those with SCD might be experiencing vascular dysregulation, or a disruption in the normal relationship between CBF and cognition. We examined whether the association between CBF and verbal memory performance differs between those with SCD (SCD+) and those without SCD (SCD-).
Linear mixed-effects models were used to investigate whether the voxel-wise relationship between arterial spin labeling (ASL) MRI-measured CBF and verbal memory performance was modified by SCD among a group of 70 cognitively normal older adults (35 SCD+, 35 SCD-; mean age=72) matched on age, gender, and symptoms of depression.
Results indicated that the SCD- group exhibited positive associations between verbal memory and CBF within the posterior cingulate cortex, middle temporal gyrus, and inferior frontal gyrus, whereas the SCD+ group displayed negative associations between verbal memory and CBF within the posterior cingulate cortex, middle temporal gyrus, hippocampus, fusiform gyrus, and inferior frontal gyrus.
Findings suggest that, while higher CBF is supportive of memory function in those without SCD, higher CBF may no longer support memory function in those presenting with SCD, perhaps reflecting neurovascular dysregulation. (JINS, 2018, 24, 213-223).
主观认知下降（SCD），即尽管神经心理学测试表现正常，但自我报告认知下降，是客观认知下降和阿尔茨海默病（AD）的一个风险因素。虽然导致 SCD 的大脑机制尚未明确，但研究表明其与血管危险因素和脑血流（CBF）改变有关，这提出了这样一种假设，即那些有 SCD 的人可能经历血管调节异常，或 CBF 与认知之间的正常关系中断。我们研究了 SCD（SCD+）和无 SCD（SCD-）个体之间，CBF 与言语记忆表现之间的关联是否存在差异。
线性混合效应模型用于研究在一组 70 名认知正常的老年人（35 名 SCD+，35 名 SCD-；平均年龄=72 岁）中，动脉自旋标记（ASL）MRI 测量的 CBF 与言语记忆表现之间的体素相关性是否因 SCD 而改变，这些老年人在年龄、性别和抑郁症状方面相匹配。
结果表明，SCD-组在后扣带回皮质、颞中回和额下回内，言语记忆与 CBF 之间呈正相关，而 SCD+组在后扣带回皮质、颞中回、海马体、梭状回和额下回内，言语记忆与 CBF 之间呈负相关。
研究结果表明，在无 SCD 的个体中，较高的 CBF 对记忆功能有支持作用，而在出现 SCD 的个体中，较高的 CBF 可能不再支持记忆功能，这可能反映了神经血管调节异常。（JINS，2018，24，213-223）。
