1. Understanding Stroke Slideshow Pictures
2. Take the Stroke Quiz
3. Slideshow: Atrial Fibrillation Causes, Tests, and Treatment

Vascular dementia is not a single disease but a group of conditions relating to different vascular problems. What all the conditions have in common is that a critical part of the brain does not receive enough oxygen. The vascular damage underlying stroke-related dementia occurs in several different patterns.

• Multi-infarct dementia - Occurs after a series of strokes in different parts of the brain
  
  
• Single-infarct dementia - Occurs when one large vascular lesion causes a severe infarction, or there is a single infarction in a strategic area of the brain
  
  
• Dementia due to lacunar lesions - Occurs when only the smaller arteries are affected, causing multiple small infarctions
  
  
• Binswanger disease - Also a disease of small arteries, but the damage primarily occurs in the white matter area of the brain
  
  
• Dementia due to hemorrhagic (bleeding) stroke - Occurs when a blood vessel bursts causing bleeding in the brain

The major cause of the vascular lesions underlying stroke-related dementia is untreated high blood pressure (hypertension). Diabetes, atherosclerosis (“hardening of the arteries”), heart disease, high cholesterol, peripheral vascular disease, and smoking are other risk factors. Other causes include uncommon vascular diseases.

Vascular dementia may occur with Alzheimer's Disease. ApoE4 is a protein whose main role is to help transport cholesterol in the blood. A high level of this protein in the blood poses a significant risk factor for Alzheimer dementia and has been linked to vascular dementia.