[Update on vascular dementias].

The concept of vascular dementia greatly evolved since Hachinski's description of multi-infarct dementia. Vascular dementias are reviewed with emphasis on current diagnostic criteria, elusive natural history, neuroradiological aspects, difficult epidemiological features and intriguing links with Alzheimer's disease. The recent proposed shift from vascular dementias to a broader definition of "vascular cognitive disorders", including non demented subjects with "vascular cognitive impairment", is described, followed by a brief review of current treatments.