On the possible relationship of cortical microvascular pathology to blood brain barrier changes in Alzheimer's disease.

A group of alterations in the structure of cortical microvessels is described in the brain tissue of neuropathologically confirmed patients with Alzheimer's disease. These changes include irregular thickening of the vessel walls, infiltration with amyloid and the serum P component of amyloid, loss of the perivascular neural plexus and the frequent occurrence of pits and lacunae in vessel walls. The possibility that these alterations may be related to blood brain barrier defects is suggested.