Multi-infarct dementia is a form of dementia caused by large numbers of small blood clots (emboli) in the brain that starve the brain cells of oxygen.

This disease mainly affects elderly people with arteriosclerosis (hardening of the arteries). Risk factors for arteriosclerosis include high blood pressure, raised cholesterol and smoking. An irregular heart beat (atrial fibrillation) can give rise to tiny blood clots, which can lodge in the brain and cause strokes too.

When the disease is diagnosed, nothing can be done about the damage that has occurred. But there are possibilities of preventing further brain damage. The cause of this disease is in principle identical to that of a stroke caused by a large blood clot. But in a person with multi-infarct dementia, the clots occur only in the small diameter blood vessels.