Clinically diagnosed Alzheimer's disease: Autopsy results in 150 cases

Abstract

One hundred fifty autopsy brains from patients with clinically diagnosed Alzheimer's disease (AD) were examined pathologically. The brains were received consecutively over a 3-year period from numerous sources as part of research program in which one brain half was frozen for biochemical studies and the other half was fixed in formalin One hundred thirty-one (87%) of the 150 cases fulfilled histological criteria for AD, with or without additional findings, such as Parkinson's disease or stroke. At least a minimal degree of amyloid angiopathy was found in every brain showing histopathological abnormalities of AD. Twenty-three (18%) of the 131 AD brains had Lewy bodies in neurons of the substantia nigra. Thirteen of the 19 non-AD cases were diagnosed as other neurodegenerative disorders. In only 2 cases was no histological correlate for the patient's dementia found. We conclude that (1) the many physicians who diagnosed these cases did so highly accurately; (2) degenerative changes in the substantia nigra were more common in patients with AD than has been reported for the general aged population; (3) amyloid angiopathy was a constant accompaniment of AD, although its severity varied widely; (4) vascular dementia was rarely clinically misdiagnosed as AD; (5) neuropathological findings were insufficient to account for the clinical syndrome of dementia in less than 2% of cases; (6) the histological criteria established by the National Institutes of Health/American Association of Retired Persons Research Workshop on the Diagnosis of Alzheimer's Disease worked well in assessing this large series.