Biomarkers of cerebrovascular disease in dementia.

There is increasing recognition that cerebrovascular disease contributes significantly to the development and progression of patients with dementia. The concepts of pure vascular and pure degenerative dementia have been replaced with a recognition that, in many patients, there is a spectrum of neurodegenerative and vascular processes. This is supported by preliminary studies showing response to vascular therapeutics and ventriculo-peritoneal shunting in patients with Alzheimer's disease. This article examines the imaging biomarkers that are available for the characterization of microvascular abnormality in the ageing brain, with particular reference to microvascular angiopathy, cerebral embolic disease, orthostatic hypotension and abnormalities of Monro-Kellie homeostasis.