Alzheimer病引起的很多神经炎斑块。刚果红染色显示淀粉样核心。一些外周脑动脉也可能受累及。还可能出现与β淀粉样蛋白相关的问题,但具体的发病机制不是很清楚。有趣的是，淀粉样蛋白遗传密码位于21号染色体上，并且活到40岁的21三体症患者出现Alzheimer病不尽相同。
A number of neuritic plaques with Alzheimer's disease are seen here. They have an amyloid core as seen here with Congo red stain. Small peripheral cerebral arteries may also be involved. There appears to be a problem with beta amyloid precursor protein, but the exact pathogenesis is unknown. It is interesting that the gene coding for cerebral amyloid is on chromosome 21--and persons with trisomy 21 living to age 40 invariably develop Alzheimer's disease.