Vascular dementia is loss of mental function due to destruction of brain tissue because its blood supply is reduced or blocked. The cause is usually strokes, either a few large ones or many small ones.
Disorders that damage blood vessels to the brain, usually strokes, can cause dementia.
Symptoms may occur in steps, not gradually.
Dementia in people who have risk factors or symptoms of a stroke is often vascular dementia.
Eliminating the risk factors for strokes may help delay or prevent further damage.
Vascular dementia is the second most common cause of dementia among older people.
Dementia is a slow, progressive decline in mental function including memory, thinking, judgment, and the ability to learn. Dementia differs from delirium, which is characterized by an inability to pay attention, disorientation, an inability to think clearly, and fluctuations in the level of alertness.
A series of strokes may result in vascular dementia. These strokes are more common among men and usually begin after age 70.
Risk factors for vascular dementia include the following:
High blood pressure, diabetes, and atherosclerosis damage blood vessels in the brain. Atrial fibrillation increases the risk of strokes due to blood clots from the heart. Disorders that cause excessive clotting also increase the risk of strokes. Unlike other types of dementia, vascular dementia can sometimes be prevented by correcting or eliminating the risk factors for strokes.
Clots and Clogs: Causes of Ischemic Stroke
Strokes can destroy brain tissue by blocking the blood supply to parts of the brain. An area of brain tissue that is destroyed is called an infarct.
Dementia may result from a few large strokes or, more commonly, many small ones. Some of these strokes seem minor or may not even be noticed. They cause little or no muscle weakness and no paralysis. However, people may continue to have small strokes, and after enough brain tissue is destroyed, dementia can develop. Thus, vascular dementia may develop before strokes cause severe symptoms or sometimes even any noticeable symptoms.
Vascular dementia includes the following, which may overlap somewhat:
Multi-infarct dementia: Dementia is caused by several strokes, usually involving medium-sized blood vessels.
Lacunar disease: Sometimes this term is used to describe multi-infarct dementia caused by many lacunar infarcts, which are strokes caused by blockages in small blood vessels.
Binswanger dementia: Several small blood vessels are blocked (causing lacunar infarcts) in people who have severe, poorly controlled high blood pressure and a blood vessel (vascular) disorder that affects blood vessels throughout the body.
Strategic single-infarct dementia: A single area of brain tissue in a crucial area is destroyed.
Vascular dementia often occurs with Alzheimer disease (as mixed dementia).
Unlike dementia caused by Alzheimer disease, vascular dementia may progress in steps. Symptoms may worsen suddenly, then plateau or lessen somewhat. They then become worse months or years later when another stroke occurs. Dementia that results from many small strokes usually progresses more gradually than that due to a few large strokes. The small strokes may be so subtle that dementia may seem to develop gradually and continuously instead of in steps.
Symptoms of vascular dementia (memory loss, difficulty planning and initiating actions or tasks, slowed thinking, and a tendency to wander) are similar to those of other dementias. However, compared with Alzheimer disease, vascular dementia tends to cause memory loss later and to affect judgment and personality less. People with vascular dementia may have particular difficulty planning and initiating actions, and their thinking may be noticeably slow.
Symptoms can vary depending on what part of the brain is destroyed. Usually, some aspects of mental function are not impaired because the strokes destroy tissue in only part of the brain. Thus, people may be more aware of their losses and more prone to depression than people with other types of dementia.
As more strokes occur and dementia progresses, people may have other symptoms due to the strokes. An arm or a leg may become weak or paralyzed. People may have difficulty speaking. For example, they may slur their speech. Vision may be blurred or partly or completely lost. Coordination may be lost, making walking unsteady. People may laugh or cry inappropriately. People may have difficulty controlling bladder function, resulting in urinary incontinence.
About 6 in 10 people die within 5 years after symptoms begin. It is often due to a stroke or heart attack.
The diagnosis of vascular dementia is similar to that of other dementias.
Doctors must determine whether a person has dementia and, if so, whether the dementia is vascular dementia.
A diagnosis of dementia is based on the following:
Mental status testing, consisting of simple questions and tasks, helps doctors determine whether people have dementia.
Sometimes more detailed testing (called neuropsychologic testing) is needed. This testing covers all the main areas of mental function, including mood, and usually takes 1 to 3 hours. This testing helps doctors distinguish dementia from other conditions that can cause similar symptoms, such as age-associated memory impairment, mild cognitive impairment, and depression.
Information from the above sources helps doctors usually rule out delirium as the cause of symptoms (see Table: Comparing Delirium and Dementia). Doing so is essential because delirium, unlike dementia, can often be reversed if promptly treated.
Once dementia is diagnosed, doctors suspect vascular dementia in people who have risk factors for or symptoms of a stroke. Then doctors do a thorough evaluation to check for stroke. CT or MRI is done too check for evidence of a stroke. Results of these tests can support the diagnosis but are not definitive.
Treatment of vascular dementia involves general measures to provide safety and support, as for all dementias.
Creating a safe and supportive environment can be very helpful (see Creating a Beneficial Environment for People With Dementia).
Generally, the environment should be bright, cheerful, safe, stable, and designed to help with orientation. Some stimulation, such as a radio or television, is helpful, but excessive stimulation should be avoided.
Structure and routine help people with vascular dementia stay oriented and give them a sense of security and stability. Any change in surroundings, routines, or caregivers should be explained to people clearly and simply.
Following a daily routine for tasks such as bathing, eating, and sleeping helps people with vascular dementia remember. Following a regular routine at bedtime may help them sleep better.
Activities scheduled on a regular basis can help people feel independent and needed by focusing their attention on pleasurable or useful tasks. Such activities should include physical and mental activities. Activities should be broken down in small parts or simplified as the dementia worsens.
Treating disorders that increase the risk of vascular dementia—diabetes, high blood pressure, and high cholesterol levels—can help prevent and slow or stop the progression of vascular dementia. Stopping smoking is also recommended.
To help prevent a future stroke, doctors recommend measures to manage risk factors for stroke (high blood pressure, diabetes, smoking, high cholesterol levels, obesity, and inactivity). Doctors may prescribe a drug that makes clots less likely to form, such as aspirin, or, if people have atrial fibrillation or a disorder that causes excessive clotting,warfarin (an anticoagulant). These drugs help reduce the risk of another stroke.
There is no specific treatment for vascular dementia. Sometimes cholinesterase inhibitors (such as rivastigmine) and memantine—the drugs used for Alzheimer disease—are given because some people with vascular dementia also have Alzheimer disease.
Caring for people with dementia is stressful and demanding, and caregivers may become depressed and exhausted, often neglecting their own mental and physical health. The following measures can help caregivers (See table: Caring for Caregivers):
Learning about how to effectively meet the needs of people with dementia and what to expect from them: Caregivers can get this information from nurses, social workers, organizations, and published and online materials.
Seeking help when it is needed:Caregivers can talk to social workers (including those in the local community hospital) about appropriate sources of help, such as day-care programs, visits by home nurses, part-time or full-time housekeeping assistance, and live-in assistance. Counseling and support groups can also help.
Caring for self: Caregivers need to remember to take care of themselves. They should not given up their friends, hobbies, and activities.
Before people with vascular dementia become too incapacitated, decisions should be made about medical care, and financial and legal arrangements should be made. These arrangements are called advance directives. People should appoint a person who is legally authorized to make treatment decisions on their behalf (a health care proxy). They should discuss their health care wishes with this person and their doctor. Such issues are best discussed with all concerned long before decisions are necessary.
As vascular dementia worsens, treatment tends to be directed at maintaining the person’s comfort rather than at attempting to prolong life.