The role of cerebrovascular disease when there is concomitant Alzheimer disease.

Cerebrovascular Pathologies (CVP) are the most common co-existent pathologies observed in conjunction with Alzheimer disease. CVP rarely exists in isolation in later life, and CVP most likely plays a supporting role, rather than a sole leading role, in the pathogenesis of dementia. Our goal is to illustrate CVP's role using neuroimaging biomarkers. First, we discuss the frequency of CVP and present data from population-based Mayo Clinic Study of Aging. Here, we used a novel metric for identifying individuals with cerebrovascular imaging abnormalities (that we designate as "V+") and present the frequency of V-/V+ in the context of absence and presence of β-amyloid elevation (designated A-/A+). Next, we discuss the contribution of CVP to neurodegeneration and use hippocampal volume loss over time in a subset of participants categorized as A-V-, A-V+, A+V-, A+V+. Lastly, we discuss the contribution of CVP to cognitive impairment and conclude with the considerations for design of future studies. This article is part of a Special Issue entitled: Vascular Contributions to Cognitive Impairment and Dementia edited by M. Paul Murphy, Roderick A. Corriveau and Donna M. Wilcock.