Vascular dementia is caused by decreased blood supply to the brain. This most often is caused by blockage or narrowing of arteries. One of the main ways that arteries become blocked or narrowed is by the same disease processes that cause heart disease. Therefore, the factors associated with heart disease are also associated with vascular dementia. Risk factors include:
Strokes (infarcts) and ministrokes: Many people develop vascular dementia after suffering a stroke (infarct) or a ministroke. This common type of vascular dementia is sometimes called multi-infarct dementia. The stroke causes parts of the brain to die, which is what leads to dementia. Strokes often cause physical symptoms, depending upon what part of the brain is affected, but ministrokes may happen without obvious external symptoms. Vascular dementia most commonly develops when the stroke occurs on the left side of the brain or when it involves the memory center of the brain, the hippocampus. A doctor may recommend scans of the brain — computerized tomography (CT) or magnetic resonance imaging (MRI) — for diagnostic purposes if a stroke is suspected. About one-third of people who had no dementia symptoms before the stroke will develop vascular dementia afterwards, usually within a year.
High blood pressure (hypertension): High blood pressure is a leading cause of vascular dementia, accounting for approximately half of the cases. High blood pressure may cause the form of vascular dementia known as subcortical vascular dementia (Binswanger disease), which affects the white matter of the brain.
Other causes: Vascular dementia can also be caused by other conditions that reduce blood flow to the brain, including certain autoimmune diseases (e.g., lupus eythematosus, temporal arteritis), certain inherited (genetic) diseases, infections of the heart (endocarditis), brain hemorrhage, profoundly low blood pressure.
Dorsey, J, White, M, et al. HelpGuide.org. Vascular Dementia: Signs, Symptoms, Prognosis and Support. Available at: http://www.helpguide.org/elder/vascular_dementia.htm. Retrieved March 30, 2009.