Vascular Dementia

In vascular dementia (multi-infarct dementia), the ability to remember, think, understand, communicate, and control behavior declines because of brain damage due to strokes.

Abilities often decline in steps (after each stroke), but they can decline more gradually. Unlike other types of dementia, vascular dementia can sometimes be prevented by correcting or eliminating the risk factors for strokes.

Vascular dementia often occurs with Alzheimer's disease (as mixed dementia). The strokes that cause vascular dementia are more common among men and usually begin after age 70. Risk factors for vascular dementia include high blood pressure, abnormal heart rhythms, diabetes, and atherosclerosis. These disorders damage blood vessels in or leading to the brain. People who smoke or have smoked are also at increased risk.

In a stroke, the blood supply to an area of the brain is blocked, causing brain tissue in that area to die. The dead tissue is called an infarct. Dementia may result from a few large strokes or from many small strokes (a disorder called Binswanger's disease).

Symptoms

Unlike Alzheimer's disease, vascular dementia may progress in steps. Symptoms may worsen suddenly, then remain the same (plateau). Months or years later when another stroke occurs, symptoms worsen again. Dementia that results from many small strokes progresses more gradually than that due to a few large strokes.

Symptoms are similar to those of other dementias. They include memory loss, difficulty doing usual daily activities, and a tendency to wander. Vascular dementia may affect judgment and personality less than Alzheimer's disease does. Also, symptoms can vary depending on what area of the brain is affected. Usually, some aspects of mental function are not affected, because the strokes destroy tissue in only part of the brain. People with vascular dementia are thought to be more aware of their losses and more prone to depression than people with Alzheimer's disease. Death usually occurs about 5 years after symptoms begin. Death is often due to a stroke or heart attack.

Diagnosis and Treatment

Once dementia is diagnosed, doctors suspect vascular dementia if a person has risk factors for a stroke or symptoms of a stroke. These symptoms include partial loss of sight, slow and slurred speech, weakness or paralysis of one leg, and difficulty walking. Computed tomography (CT) or magnetic resonance imaging (MRI) may be done. Results of these tests can support the diagnosis but are not definitive.

Generally, treatment of vascular dementia is the same as that of all dementias. Treatment also includes measures to prevent more strokes. For example, treating disorders that increase the risk of a stroke, such as atherosclerosis, coronary artery disease, high blood pressure, diabetes, and abnormal heart rhythms, may help prevent vascular dementia or slow or stop its progression. Modifying other risk factors for stroke is also recommended. For example, people who smoke should stop.

Many strokes are caused by blood clots. Therefore, anticoagulants, which make blood less likely to clot, are given to some people who are at risk of developing clots. Taking aspirin can also help prevent blood clots. Warfarin, a strong anticoagulant, is given to some people who have an abnormal heart rhythm (particularly atrial fibrillation), which can lead to stroke.