MID affects both sexes but affects men more often than women. The disorder usually affects older people, over 55 years, with the onset averaging around age 65. The disorder is associated with atherosclerosis, a condition where fatty deposits occur in the inner lining of the arteries.
Atherosclerotic plaque damages the lining of an artery.
Cholesterol and other fats also collect at this site, forming a mass within the lining of the artery. This occurs when atherosclerotic plaques cause multiple, scattered blood clots that block off the small blood vessels and prevent localized areas of the brain from receiving blood flow and oxygen. The consequences vary depending on the location and severity of the infarctions. Memory impairment is often an early symptom of the disorder, followed by judgment impairment. Personality and mood changes accompany the deteriorating mental condition.