de Eulate Reyes García, Goñi Irene, Galiano Alvaro, Vidorreta Marta, Recio Miriam, Riverol Mario, Zubieta José L, Fernández-Seara María A
Department of Radiology, Clínica Universidad de Navarra, Pamplona, Spain.
Department of Biomedical Engineering, TECNUN Engineering School, University of Navarra, San Sebastián, Spain.
J Alzheimers Dis. 2017;58(2):585-595. doi: 10.3233/JAD-161222.
There is increasing evidence of a vascular contribution to Alzheimer's disease (AD). In some cases, prior work suggests that chronic brain hypoperfusion could play a prime pathogenic role contributing to the accumulation of amyloid-β,while other studies favor the hypothesis that vascular dysfunction and amyloid pathology are independent, although synergistic, mechanisms contributing to cognitive impairment. Vascular dysfunction can be evaluated by assessing cerebral blood flow impairment. Phase contrast velocity mapping by MRI offers a non-invasive means of quantifying the total inflow of blood to the brain. This quantitative parameter could be a sensitive indicator of vascular disease at early stages of AD. In this work, phase contrast MRI was used to evaluate cerebral hemodynamics in patients with subjective memory complaints, amnestic mild cognitive impairment, and mild to moderate AD, and compare them with control subjects. Results showed that blood flow and velocity were decreased in the patients with cognitive dysfunction and the decrease correlated with the degree of cognitive impairment as assessed by means of neuropsychological tests. Total cerebral blood flow measurements were clearly reduced in AD patients, but more importantly appeared to be sensitive enough to distinguish between healthy subjects and those with mild cognitive impairment. A quantitative measurement of total brain blood flow could potentially predict vascular dysfunction and compromised brain perfusion in early stages of AD.
越来越多的证据表明血管因素在阿尔茨海默病（AD）中起作用。在某些情况下，先前的研究表明慢性脑灌注不足可能在β-淀粉样蛋白积累过程中起主要致病作用，而其他研究则支持血管功能障碍和淀粉样病变是独立但协同的导致认知障碍的机制这一假说。血管功能障碍可通过评估脑血流损伤来进行评估。MRI相位对比速度成像提供了一种无创量化脑总血流量的方法。这一量化参数可能是AD早期血管疾病的敏感指标。在这项研究中，利用相位对比MRI评估了有主观记忆主诉、遗忘型轻度认知障碍以及轻度至中度AD患者的脑血流动力学，并与对照受试者进行比较。结果显示，认知功能障碍患者的血流和速度降低，且这种降低与通过神经心理学测试评估的认知障碍程度相关。AD患者的脑总血流量测量值明显降低，但更重要的是，它似乎足够敏感，能够区分健康受试者和轻度认知障碍患者。脑总血流量的定量测量有可能在AD早期预测血管功能障碍和脑灌注受损情况。
