Neuropathology and general autopsy findings in nondemented aged subjects

Abstract

A retrospective study of the essential general pathology and neuropathological features in 100 nondemented individuals aged 65 years or older (mean 81.23 ± 5.47 y) was performed using semiquantitative methods. 91% of the patients had a history of hypertension, 31% malignancies, 24% COPD, 18% myocardial infarction, and 4% stroke. Major causes of death were cardiovascular decompensation, pneumonia, acute myocardial infarction, and malignancies. General autopsy revealed severe systemic and coronary atherosclerosis in 86 and 90%, respectively, renal angioangiolosclerosis in 82%, acute or recurrent myocardial infarction in 65%, and other diseases. Neuropathology showed average brain weight of 1,163 ± 113 g, mild to moderate brain atrophy, absent to mild atherosclerosis of large cerebral arteries in 46%, mild, moderate and severe one in 31, 17, and 6%, respectively. There were considerable discrepancies in the severity between generalized/ aortic and intracranial atherosclerosis, only less than one-third being comparable. Negative Khachaturian criteria and CERAD Stage 0 were observed in 83 and 86%, respectively, only 13% with CERAD Stage A, and 1% Stage B. Braak neuritic stages ranged from 0 to II (53%), II - III (29%) to III - IV (18%), none scoring Grade V or VI. The average Braak score was 2.3 ± 0.8. Vascular pathologies were common; CAA was absent in 61%, mild or moderate in 36% and severe in 3%. Mild to severe lacunar state in basal ganglia and/or white matter was seen in 73%, hippocampal sclerosis in 3 cases, while only 9% were free of cerebrovascular lesions. Lewy bodies were observed in 5 brains involving substantia nigra (n = 3), cerebral cortex (n = 1) and medulla oblongata (n = 1), 1 case representing incidental Lewy body disease. τ pathology in brainstem was observed in 60 cases (60%). Mixed cerebral pathologies (cerebrovascular lesions and moderate neuritic Braak stages) were observed in 6 cases (mean age 89.6 y). The importance of mixed pathologies in nondemented elderly, being less frequent than in other studies, remains to be elucidated.