β-Amyloid Plaques and Dementia: An Immunohistochemical Study

Senile plaques (SPs) and NFTs were immunohistochemically studied in the temporal lobe of 246 autopsy brains from non-demented and demented old people, using antibodies to synthetic polypeptide (1–24) of β-protein of cerebrovascular amyloid and to human tau protein. Dementia was present in 64% of 28 cases with many NFTs, while it was present only 33% of 43 cases in which there were many SPs but a few NFTs. The rate of prevalence of β-immunoreactive SPs increased with age in both demented and non-demented subjects. It was not significantly different between non-demented group (40% of 161 cases), and senile (47% of 19 cases) or vascular (30% of 27 cases) dementia groups. These findings suggest that β-immunoreactive SPs may be related to aging but may not be closely linked to dementia.