The immunohistochemical evidence of amyloid diffuse deposits as a pathological hallmark in Alzheimer's disease.

We performed an immunocytochemical study of cerebral cortex from cases of Alzheimer's disease and from aged nondemented controls, using periodic acid pretreatment and polyclonal beta-protein antibodies. In addition to senile plaques (SP) and amyloid angiopathy (AA), the beta-protein antibodies detected band-like deposits present throughout the cortical layers. Moreover, large plaque-like infiltrations with diffuse and amorphous characteristics were observed in the cortical gray and white matter, and these deposits were often associated with capillaries. Our results suggest that an abundance of these lesions, which were detected only with this immunostaining procedure in Alzheimer cortex, may be characteristic of Alzheimer's disease.