The physiological mechanisms of age-related cognitive decline remain unclear, in no small part due to the lack of longitudinal studies. Extant longitudinal studies focused on gross neuroanatomy and diffusion properties of the brain. We present herein a longitudinal analysis of changes in arterial pulsatility – a proxy for arterial stiffness – in two major cerebral arteries, middle cerebral and vertebral. We found that pulsatility increased in some participants over a relatively short period and these increases were associated with hippocampal shrinkage. Higher baseline pulsatility was associated with lower scores on a test of fluid intelligence at follow-up. This is the first longitudinal evidence of an association between increase in cerebral arterial stiffness over time and regional shrinkage.

与年龄相关的认知能力下降的生理机制仍不清楚，这在很大程度上是由于缺乏纵向研究。现有的纵向研究主要集中在大脑的总体神经解剖学和扩散特性。我们在此对大脑中动脉和椎动脉这两条主要大脑动脉的动脉搏动（动脉僵硬度的代表）变化进行纵向分析。我们发现一些参与者的搏动在相对较短的时间内增加，并且这些增加与海马体收缩有关。较高的基线搏动与随访时流体智力测试的较低分数相关。这是脑动脉僵硬度随时间增加与区域收缩之间存在关联的第一个纵向证据。