Background: The determinants of the progressive decrement of cognition in normal aging are still a matter of debate. Alzheimer disease (AD)-signature markers and vascular lesions, but also psychological variables such as personality factors, are thought to have an impact on the longitudinal trajectories of neuropsychological performances in healthy elderly individuals.

Objective: The current research aimed to identify the main determinants associated with cognitive trajectories in normal aging.

Methods: We performed a 4.5-year longitudinal study in 90 older community-dwellers coupling two neuropsychological assessments, medial temporal atrophy (MTA), number of cerebral microbleeds (CMB), and white matter hyperintensities (WMH) at inclusion, visual rating of amyloid and FDG PET at follow-up, and APOE genotyping. Personality factors were assessed at baseline using the NEO-PIR. Univariate and backward stepwise regression models were built to explore the association between the continuous cognitive score (CCS) and both imaging and personality variables.

Results: The number of strictly lobar CMB at baseline (4 or more) was related to a significant increase in the risk of cognitive decrement. In multivariable models, amyloid positivity was associated with a 1.73 unit decrease of the CCS at follow-up. MTA, WMH and abnormal FDG PET were not related to the cognitive outcome. Among personality factors, only higher agreeableness was related to better preservation of neuropsychological performances.

Conclusion: CMB and amyloid positivity are the only imaging determinants of cognitive trajectories in this highly selected series of healthy controls. Among personality factors, higher agreeableness confers a modest but significant protection against the decline of cognitive performances.

背景：正常衰老过程中认知逐渐下降的决定因素仍然存在争议。阿尔茨海默病 (AD) 特征标志物和血管病变，以及诸如人格因素等心理变量，被认为对健康老年人的神经心理表现的纵向轨迹有影响。

目的：目前的研究旨在确定与正常衰老过程中认知轨迹相关的主要决定因素。

方法：我们对 90 名老年社区居民进行了一项为期 4.5 年的纵向研究，结合两项神经心理学评估、内侧颞叶萎缩 (MTA)、脑微出血 (CMB) 数量和纳入时的白质高信号 (WMH)、淀粉样蛋白的视觉评级FDG PET 和 APOE 基因分型。人格因素在基线时使用 NEO-PIR 进行评估。建立单变量和向后逐步回归模型来探索连续认知评分 (CCS) 与成像和人格变量之间的关联。

结果：基线时严格的脑叶 CMB 数量（4 个或更多）与认知减退风险的显着增加有关。在多变量模型中，淀粉样蛋白阳性与随访时 CCS 降低 1.73 个单位相关。MTA、WMH和FDG PET异常与认知结果无关。在人格因素中，只有更高的宜人性与更好地保存神经心理表现有关。

结论：CMB 和淀粉样蛋白阳性是这一系列高度选择的健康对照中认知轨迹的唯一成像决定因素。在人格因素中，较高的宜人性可以提供适度但重要的保护，防止认知能力下降。