Dementia is a decline in a person's mental capacities and intellectual abilities that is great enough to affect the person's normal daily functioning. Vascular dementia is dementia that is caused by disease of the blood vessels of the brain (cerebrovascular disease).
Vascular dementia is caused by cerebrovascular disease that occurs almost entirely in the elderly. People with vascular dementia generally experience a decline in thought processes (cognitive function) that follows specific steps. This decline is often punctuated by small strokes—ruptures of tiny blood vessels in the brain. People experiencing vascular dementia often have problems with memory, abstract thinking, object identification or recognition, speech creation, speech comprehension, and motor activities.
Causes and symptoms
The signs of dementia often begin with impaired memory function. Sometimes a person has difficulty learning new things or remembering new events, and sometimes the person has difficulty recalling events or things that he or she used to know. Other signs of dementia include impairment in other areas of thought processing. Sometimes a person with vascular dementia may have difficulty producing coherent speech, or may have other language impairments, such as problems understanding spoken or written language. The signs of vascular dementia are similar to those of Alzheimer's disease (AD).
Difficulty with motor activities is a problem for some people with vascular dementia. Things that require hand-eye coordination, such as tying shoes or undoing buttons, are examples of motor activities that may be impaired. People with vascular dementia may also have difficulty recognizing familiar objects, or may be unable to name them. Problems organizing things, putting events in sequence, or problems performing other types of abstract thinking may be present.
Some people with vascular dementia exhibit neurological signs that indicate the presence of cerebrovascular disease. They may have weakness of the arms or legs, abnormal reflexes, or abnormalities in the way they walk. Some people also exhibit behavioral disturbances related to the dementia. A person can be violent or aggressive towards others—often his or her caretaker. The person may act impulsively and irritably, and sometimes scream.
Vascular dementia is thought to be caused by small strokes that interfere with blood flow to the brain. Usually, vascular dementia is caused by many small strokes over time, rather than one large stroke . Sometimes this is referred to as multi-infarct dementia (MID). If the vascular dementia is caused by one large stroke, or develops in less than three months, then it is called "acute onset vascular dementia." Acute onset vascular dementia is rare.
In most countries, vascular dementia is a much less common form of dementia than AD. This is true in North America and Europe, but is not so in Japan, where it is more common than AD. Overall, vascular dementia is the second most common form of dementia, after AD. About 10–20% of patients who experience dementia have the vascular form of the disorder. The difference in prevalence in different countries may result from different lifestyle factors rooted in the culture.
Vascular dementia is more common in men than in women, which may be because men are more likely than women to suffer from strokes. Vascular dementia becomes increasingly prevalent as people grow older. The number of people affected by vascular dementia rises dramatically during and after the sixth decade. Vascular dementia usually occurs at a younger age than AD.
The first step in the diagnosis of vascular dementia is to verify that dementia is present. The DSM indicates that impairments to memory must be present for a diagnosis of vascular dementia. Memory problems can include difficulties in learning and retaining new information, problems remembering past events, or things that were learned before dementia took root.
In addition to memory impairment, the DSM also specifies that one or more other impairments must be present. These impairments can include language problems that encompass not being able to form speech and/or not being able to understand language, either spoken or written. The patient may have problems performing activities that require hand-eye coordination such as tying shoes, even though motor function is normal. Another possible impairment is a problem recognizing or identifying objects, although the person is able to use his or her sense organs fully. Also, problems doing tasks such as organizing things, planning events, putting things into sequence, or problems thinking abstractly may exist.
If the patient has memory problems and one or more other impairments, For a diagnosis of vascular dementia to be made, these impairments must cause problems for the patient's functioning in important parts of his or her daily life. Also, the patient must be significantly less able to function than during a previous time. In addition, the problems cannot occur during the course of an event that is categorized as a delirium . There must be evidence that the problem is a result of cerebrovascular disease.
If the dementia occurs without any other significant signs or symptoms, then it is classified as uncomplicated. There are three other possible classifications as given by the DSM . These are based on the predominant feature of the dementia. They are: vascular dementia with delirium, vascular dementia with delusions , and vascular dementia with depressed mood. If there are significant behavioral disturbances occurring as a result of the dementia, then that is specified.
Vascular dementia and AD are similar in many ways, and can be confused. The most significant difference between the two is that vascular dementia can be diagnosed using physiological evidence of cerebrovascular disease. Also, AD generally occurs first as a slow loss of memory function, and then as a gradual decline into eventual dementia. Vascular dementia, however, generally occurs suddenly. The patient often declines in a stepwise fashion, with each step occurring after a stroke.
The treatments for vascular dementia focus on attempts to slow or halt the progression of the disorder and alleviate some of the symptoms. The disorder cannot be cured or reversed. The most common way to treat vascular dementia is to try to prevent further strokes. Treatments include diet and drug treatment for hypertension (high blood pressure), aspirin therapy, smoking cessation, avoidance of heavy alcohol use, and stress reduction. Some drugs that are used to treat mild AD are being studied for their effectiveness in treating vascular dementia.
Vascular dementia is a disorder that cannot be reversed. The progression of the disorder can, however, be slowed. Using drugs, along with lifestyle changes to prevent more strokes from occurring, can be effective at slowing the progression of vascular dementia.
Vascular dementia is generally associated with a series of strokes causing increasing mental impairment. Measures generally recommended by physicians may prevent strokes and may be effective in helping to prevent vascular dementia. These measures include such things as quitting smoking, decreasing cholesterol levels, treating hypertension by reducing sodium (salt) intake, decreasing alcohol consumption, quitting smoking, and other lifestyle changes. One study illustrated that consuming a small amount of red wine regularly reduces the risk of all forms of dementia.
See also Alzheimer's disease
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National Institute on Aging. Building 31, Room 5C27 31 Center Drive, MSC 2292 Bethesda, MD 20892. Telephone: (301) 496-1752. Web site: <www.nia.nih.gov> .
Tish Davidson, A.M.