The incidence of cerebral amyloid angiopathy in Alzheimer's disease.

The incidence and forms of cerebral amyloid angiopathy were studied in 15 cases of Alzheimer's disease using Congo red staining and polarization. Thirteen cases showed slight to severe involvement; two contained no amyloid vascular degeneration. There was a correlation between the presence of amyloid-rich plaques and cerebral amyloid angiopathy (especially the plaque-like angiopathy) but no correlation with "amyloid-poor" senile plaques or Alzheimer's neurofibrillary degeneration.