[Cerebrovascular aging]

Recent data suggest an increase in vascular pathology in ageing including changes in blood-brain barrier permeability and morphological changes in microvasculature. In the present study, cortical brain microvasculature was studied by immunohistochemistry using a monoclonal antibody against a vascular heparan sulfate proteoglycan. Vascular changes were consistently observed in ageing and included decrease in vascular density and presence of atrophic vessels. In Alzheimer's disease (AD), vascular changes were even more severe including presence of coiling vessels and glomerular loop formations. The laminar and regional distribution of these vascular alterations was correlated with the presence of neuropathological lesions (neurofibrillary tangles and amyloid deposits) suggesting a role of vascular changes in AD pathology. The degree of overlap between vascular and neurodegenerative disorders may be more substantial than previously thought. If vasculopathy in Alzheimer's disease is not directly involved in pathogenesis, it may act synergistically with other pathogenetic mechanisms including genetic and environmental factors. This aspect of pathology is particularly interesting in view of its accessibility to therapeutic interventions.