Definition of Multi-infarct dementia:

Multi-infarct dementia (MID) is a form of vascular dementia -- damage in mental function caused by strokes.

Causes, incidence, and risk factors:

Multi-infarct dementia (MID) is the most common form of vascular dementia, and the second most common cause of dementia (after Alzheimer's disease) in people over age 65.

An estimated 10 - 20% of all dementias are caused by strokes. MID affects men more often than women. The disorder usually affects people between ages 55 and 75.

"Multi-infarct" means that many areas in the brain have been injured due to a lack of blood.

Risk factors for MID include a history of:

• Hardening of the arteries (atherosclerosis)
• High blood pressure (hypertension)
• Smoking
• Stroke

Some research suggests that MID may cause Alzheimer's disease or make it get worse faster. MID may be misdiagnosed as Alzheimer's, or may be found along with Alzheimer's.