What is Multi-Infarct Dementia?
Multi-infarct dementia is the second most common cause of dementia in older people. Sometimes it is difficult to distinguish from Alzheimer’s disease, which is the most common cause of dementia in older persons. It is possible for a person to have both multi-infarct dementia and Alzheimer’s disease, making it hard for the doctor to diagnose either.
Causes Of Multi-Infarct Dementia
Multi-infarct dementia is caused by a series of strokes that damage or destroy brain tissue. A stroke occurs when blood cannot get to the brain. A blood clot or fatty deposits (called plaques) can block the vessels that supply blood to the brain, causing a stroke.
Who is Affected?
Multi-infarct dementia usually affects people between the ages of 60 and 75. Men are slightly more likely than women to have this disease. the most important risk factor for multi-infarct dementia is high blood pressure. It is rare for a person without high blood pressure to develop multi-infarct dementia.
Symptoms that begin suddenly may be a sign of multi-infarct dementia. In addition to confusion and problems with recent memory, symptoms of multi-infarct dementia may include:
- wandering or getting lost in familiar surroundings.
- moving with rapid, shuffling steps.
- loss of bladder or bowel control.
- laughing or crying inappropriately.
- difficulty following instructions.
- problems handling money.
Multi-infarct dementia is often a result of a series of small strokes, called ministrokes or TIAs (transient ischmic attacks). The symptoms of a TIA often are very slight. They may include:
- mild weakness in an arm or a leg.
- slurred speech.
The symptoms generally do not last for more than a few days. Several TIAs may occur before the person notices any symptoms of multi-infarct dementia. People with muti-infarct dementia may improve for short periods, then decline upon having further strokes.
People who show signs of dementia or who have a history of strokes should have a complete physical exam. The doctor will ask the patient and the family about:
- the patient’s diet
- sleep patterns
- personal habits
- past strokes
- other medical problems
- recent illnesses
- stressful events
To look for signs of stroke, the doctor will check for weakness or numbness in the arms or legs, difficulty with speech, or dizziness. To check for other health problems that could cause symptoms of dementia, the doctor may order office or laboratory tests. Tests may include:
- blood pressure reading.
- an electroencephalogram (EEG).
- a test of thyroid function.
- blood tests.
- computerized tomography (CT) scan.
- magnetic resonance imaging (MRI).
Both CT scans and MRI tests take pictures of sections of the brain. The pictures are then displayed on a computer screen to allow the doctor to see inside the brain. (CT scans and MRI tests are painless and do not require surgery.) In addition, the doctor may send the patient to a psychologist or psychiatrist to test reasoning, learning ability, memory, and attention span.
While no treatment can reverse damage that has already been done, treatment to prevent additional strokes is very important. High blood pressure, the primary risk factor for mutli-infarct dementia, can be treated successfully. Diabetes also is a treatable risk for stroke. To prevent additional strokes, doctors may prescribe medicines to control high blood pressure, high cholesterol, heart disease, and diabetes. They will counsel patients about good health habits such as exercising, avoiding smoking and drinking alcohol. The patient may require a special diet.
Doctors sometimes prescribe aspirin or other drugs to prevent clots from forming in the small blood vessels. Drugs also can be prescribed to relieve restlessness or depression or to help the patient sleep better. Sometimes doctors recommend a surgery known as carotid endartectomy. This surgery is done to remove blockage in the carotid artery, the main blood vessel to the brain. Studies are under way to see how well this surgery works in treating patients with mult-infarct dementia. Some scientists are also studying drugs that increase the flow of blood to the brain.
Helping Someone with Multi-Infarct Dementia
Family members and friends can help the patient cope with mental and physical problems. They can encourage daily routines and regular social and physical activities. By talking about events and daily activities they can help reinforce mental abilities. Lists, alarm clocks, and calendars may help to remind the patient of important times and events.