Neurodegenerative and cerebrovascular diseases have been related for more than a century. Epidemiological data show that main vascular risk factors are also risk factors for Alzheimer disease. Experimental evidences demonstrate that some of those risk factors accelerate the progress of Alzheimer lesions, mainly by acting on the amyloid cascade. Recent advances in understanding the basic mechanisms of CADASIL and familial amyloid angiopathy reveal that these forms of vascular dementias are degenerative disease of brain vessels. Modern neuroimaging techniques will allow to better understand relations between symptomatic strokes, silent infarcts, leukoaraiosis, microbleeds and degenerative pathology before the stage of dementia.