Vascular disorder in Alzheimer’s disease: role in pathogenesis of dementia and therapeutic targets

It is not clear whether Alzheimer’s Disease (AD) is primarily a neurodegenerative disorder or not. A body of evidence suggests that vascular disorder in brains of individuals with AD contributes to the extremes of this disease. This raises a question whether Alzheimer’s dementia is secondary to vascular dysfunction in the central nervous system (CNS) and, therefore, the neurodegeneration that follows is a consequence of inadequate cerebral blood flow, altered brain metabolism and failure in physiological functions of brain endothelium which represents a site at the blood–brain barrier (BBB). In this paper the evidence for a primary role of the CNS vascular system in pathogenesis of Alzheimer’s dementia is reviewed to show how alterations in transport across the BBB contribute to development of cerebral β-amyloidosis in AD. In addition, vascularly-based therapeutic strategies to limit the development of β-amyloidosis and to remove amyloid and plaques from the CNS of AD individuals are discussed.