The research found that amyloid-beta – the substance that clumps together and forms amyloid plaques – becomes depleted in the cerebrospinal fluid around the brain as long as 25 years before the onset of dementia. Fifteen years prior to onset, a positron emission tomography (PET) scan showed amyloid-beta being deposited in plaques in the brain itself.
研究发现，乙型淀粉样蛋白（amyloid-beta，这种物质会结团形成淀粉样斑块）会在痴呆症状出现前25年就消失于大脑周边的脑脊液中。痴呆症状出现前十五年，正电子发射成像术（PET）扫描显示乙型淀粉样蛋白正在大脑本身的斑块中堆积。弗莱明汉姆和国王岛研究表明，痴呆症状出现前十年，详细短期记忆测试会有不正常表现。