A cerebrovascular disease is a vascular disease of the cerebral circulation. Arteries supplying oxygen to the brain are affected resulting in one of a number of cerebrovascular diseases. Most commonly this is a stroke or mini-stroke and sometimes can be a hemorrhagic stroke. Any of these can result in vascular dementia. Hypertension (high blood pressure) is the most important contributing cause because it damages the blood vessel lining exposing collagen where platelets aggregate to initiate a repair. If maintained hypertension can change the structure of blood vessels (narrow, deformed).