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.
(See also Overview of Delirium and Dementia and Dementia.)
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.
Dementia affects mainly memory, and delirium affects mainly attention.
Dementia typically begins gradually and has no definite beginning point. Delirium begins suddenly and often has a definite beginning point.
Types of vascular dementia
There are four major types of vascular dementias:
Subcortical ischemic vascular cognitive impairment and dementia: Dementia results from tissue damage in the area of the brain under the cortex (the convoluted outer surface of the cerebrum, which is the largest part of the brain). Usually, smaller blood vessels are involved
Multi-infarct dementia: Dementia is caused by several strokes and usually involves medium-sized blood vessels.
Poststroke dementia: Cognitive decline begins immediately after or within 6 months after a stroke.
Mixed dementia: Vascular dementia occurs with another dementia, often Alzheimer disease or dementia with Lewy bodies.
Subcortical ischemic vascular cognitive impairment and dementia has several subtypes:
Multiple lacunar infarction: Blockages occur in several small blood vessels located deep within the brain.
Binswanger dementia: There are widespread blockages of small blood vessels in white matter, located in the deeper tissues of the brain. Typically, Binswanger dementia occurs in people who have severe, poorly controlled high blood pressure and a disorder that affects blood vessels throughout the body.
Other types of vascular dementias are less common. They include
Strategic single-infarct dementia: A single area of brain tissue in a crucial area is destroyed.
Cerebral amyloid angiopathy (CAA): This type causes a slow decline in mental function and episodes of difficulty seeing and speaking, weakness and numbness on one side of the body. Bleeding may occur in the brain. If it does, symptoms occur suddenly. CAA is caused by accumulation of beta-amyloid (an abnormal protein) in blood vessels in brain, Most people with Alzheimer disease have CAA, but it also occurs in the brains of many healthy older people.
Hereditary vascular dementias: These disorders affect small blood vessels. They are caused by mutations in certain genes. Two relatively common types are cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL).
Causes of Vascular Dementia
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:
Having high blood pressure
Having diabetes
Having atherosclerosis
Having atrial fibrillation, a type of irregular heart rhythm
Having high levels of fats (lipids), including cholesterol
Smoking (currently or in the past)
Having had a stroke
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.
Clogs and Clots: Causes of Ischemic Stroke
When an artery that carries blood to the brain becomes clogged or blocked, an ischemic stroke can occur. Arteries may be blocked by fatty deposits (atheromas, or plaques) due to atherosclerosis. Arteries in the neck, particularly the internal carotid arteries, are a common site for atheromas. Arteries may also be blocked by a blood clot (thrombus). Blood clots may form on an atheroma in an artery. Clots may also form in the heart of people with a heart disorder. Part of a clot may break off and travel through the bloodstream (becoming an embolus). It may then block an artery that supplies blood to the brain, such as one of the cerebral arteries. |
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. 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 other severe symptoms or sometimes even any noticeable symptoms.
Symptoms of Vascular Dementia
Unlike other dementias (which tend to progress continuously), 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 personality less. Vascular dementia tends to cause difficulty with the following earlier than Alzheimer disease.
Planning, solving problems, handling complex tasks, and using good judgment (called executive function)
Initiating actions
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.
Hereditary vascular dementias also impair mental function. CADASIL can cause migraine headaches and/or strokes. CARASIL can cause hair loss and degeneration of the bones in the spine (vertebrae) and the disks between them (spondylosis).
About 6 in 10 people die within 5 years after symptoms begin. It is often due to a stroke or heart attack.
Diagnosis of Vascular Dementia
A doctor's evaluation for dementia
Computed tomography or magnetic resonance imaging
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.
Diagnosis of dementia
A diagnosis of dementia is based on the following:
Symptoms, which are identified by asking the person and family members or other caregivers questions
Results of a physical examination
Results of mental status testing
Results of additional tests, such as computed tomography (CT) or magnetic resonance imaging (MRI)
Mental status testing, consisting of simple questions and tasks, helps doctors determine whether people have dementia.
Neuropsychologic testing, which is more detailed, is sometimes 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.
Diagnosis of vascular dementia
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 to check for evidence of a stroke.
Laboratory tests are done to check for diabetes, high lipid levels, and other disorders that increase the risk of stroke and disorders that affect blood vessels and blood flow (vascular disorders). Results of these tests can support the diagnosis of vascular dementia but are not definitive.
Genetic tests using a sample of blood may be done to check for hereditary vascular dementias. However, sometimes a skin biopsy can be done instead to confirm the diagnosis of some of these dementias (such as CADASIL).
Treatment of Vascular Dementia
Safety and supportive measures
Management of conditions that increase risk
Treatment of vascular dementia involves general measures to provide safety and support as mental function decreases, as for all dementias.
Safety and supportive measures
Creating a safe and supportive environment can be very helpful.
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.
Management of conditions that increase risk
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.
To help prevent a future stroke, doctors recommend measures to manage risk factors for stroke (such as better control of high blood pressure, diabetes, high cholesterol levels), to stop smoking, to lose weight if overweight, and to increase physical activity.
Medications
There is no specific treatment for vascular dementia. Sometimes cholinesterase inhibitors
If people have disorders that increase the risk of stroke and vascular disorders (such as diabetes and high lipid levels), medications to treat these conditions are given as needed.
Depression, if present, is treated with antidepressants.
Care for caregivers
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.
End-of-life issues
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.
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
Dementia.org: Information about the causes, symptoms, and treatments of vascular dementia.
Health Direct: Dementia Video Series: General information about dementia, recommendations about the warning signs of dementia, treatment and research, and caring for a person with dementia. Also provides links to articles on similar topics.
National Institute of Neurological Disorders and Stroke's Dementia Information Page: Information about treatments and prognosis for people with dementia and links to clinical trials.
