What Facts Should I Know about Stroke-Related Dementia?

What is the medical definition of a stroke?

Stroke (“brain attack”) is a disease of the blood vessels in and around the brain. It occurs when part of the brain does not receive enough blood to function normally and the cells die (infarction), or when a blood vessel ruptures (hemorrhagic stroke). Infarction is more common than hemorrhage and has a number of causes; for example, a vessel (artery) supplying blood to the brain can become blocked by a fatty deposit (plaque), which can form clots and send pieces into vessels further in the brain, or these arteries become thickened or hardened, narrowing the space where the blood flows (atherosclerosis). In addition, clots can arise in the heart and travel to the brain. Permanent damage to brain cells can result.

Does a stroke lead to dementia?

The symptoms of stroke vary, depending on which part of the brain is affected.

Common symptoms of stroke are sudden paralysis or loss of sensation in part of the body (especially on one side), partial loss of vision or double vision, or loss of balance. Loss of bladder and bowel control can also occur.

Other symptoms include decline in “cognitive” mental functions such as memory, speech and language, thinking, organization, reasoning, or judgment.

Changes in behavior and personality may occur.

If these symptoms are severe enough to interfere with everyday activities, they are called dementia.

Cognitive decline related to stroke is usually called vascular dementia or vascular cognitive impairment to distinguish it from other types of dementia. In the United States, it is the second most common form of dementia after Alzheimer's Disease. Vascular dementia is preventable, but only if the underlying vascular disease is recognized and treated early.

People who have had a stroke have a greater risk of dementia than people who have not had a stroke. About 1 in 10 people who have a stroke develop signs of dementia within 1 year.

Vascular dementia is most common in older people, who are more likely than younger people to have vascular diseases. It is more common in men than in women.