阿尔茨海默病（Alzheimer′s Disease, AD）与脑淀粉样血管病（Cerebral Amyloid Angiopathy,CAA）在临床及病理上存在诸多关联。本文报道了1例AD合并CAA的男性（54岁）病例,采用A/T/N框架从生物标志物层面进行AD诊断,并根据波士顿诊断标准2.0进行CAA的临床诊断,国内至今还少见报道。同时,该病例经脑脊液检测及神经分子影像证实存在β-淀粉样蛋白（Aβ）异常改变。笔者复习相关文献后综合分析,提示Aβ沉积是导致CAA和AD的共同致病途径。CAA主要病因为血管Aβ沉积,AD主要病因为神经炎性斑Aβ沉积,二者的病理改变均由Aβ清除障碍所驱动,2种疾病的病理学机制相互影响,共同导致认知功能障碍和神经功能障碍,但二者导致脑损伤的具体机制存在差异。AD相关脑损伤的机制主要与Aβ沉积引起的突触和神经元丢失有关,而CAA相关脑损伤更倾向于血管功能障碍、血管完整性破坏和出血或者脑低灌注所致。AD存在明显临床表现异质性,故对于临床上诊断为AD但未发生过脑出血的患者,也需要常规行脑MRI磁敏感加权成像扫描,以排除患者同时合并CAA的可能。

Alzheimer′s disease (AD) and cerebral amyloid angiopathy (CAA) have close clinical and pathological relationships. In this paper, a 54-year male patients with AD and CAA is reported. AD is diagnosed according to A/T/N biomarker framework, and the clinical diagnosis of CAA is based on Boston Diagnostic criteria 2.0. So far, it has not been reported in China. At the same time, the abnormal changes of β-amyloid protein (Aβ) in this case were confirmed by cerebrospinal fluid detection and neuromolecular imaging. Finally, through the review of the literature, it is expounded that the deposition of Aβ is the common pathology of CAA and AD, leading to cognitive dysfunction and neurological dysfunction. For CAA, the major event in the pathogenesis is vascular Aβ deposition, while for AD is inflammatory plaque Aβ deposition in the brain. The pathological changes of both are driven by Aβ clearance disorders. However, mechanisms of brain injury between them were different. The mechanism of AD-related brain injury is mainly related to synaptic and neuron loss caused by Aβ deposition, while CAA-related brain injury is more likely to be caused by vascular dysfunction, vascular integrity damage, hemorrhage or cerebral hypoperfusion. Since obvious clinical heterogeneity in AD, for patients with AD and without intracerebral hemorrhage, routine screening magnetic sensitivity weighted imaging scanning is needed to exclude CAA.