Johns Hopkins professor Lawrence Appel, M.D. discusses vascular dementia, which often occurs after stroke.
Since Ronald Reagan announced to the world in 1994 that he had Alzheimer’s disease, Alzheimer’s disease has been in the consciousness of many Americans. Alzheimer’s disease is the most common form of dementia, causing problems with thinking, memory, and speaking, but it’s not the only kind of dementia. In fact, if you’ve had a stroke, a common consequence can be the development of a neurological disorder called vascular dementia.
Studies have shown that three months after a stroke, about 30% of people show signs of dementia, including impairments in their learning, attention, and ability to remember. Vascular dementia results from the interruption of blood flow that occurs during a stroke and injures the brain.
Symptoms of vascular dementia vary from person to person, but the most common ones are:
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poor concentration
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problems with language
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memory problems
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difficulty following instructions
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confusion
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poor judgment and problem-solving
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depression
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wandering and becoming lost in surroundings that were once familiar.
These symptoms are not unique to vascular dementia, and can occur in other forms of dementia, including Alzheimer’s disease. However, the symptoms of vascular dementia usually develop abruptly and worsen in a stepwise manner (that is, the symptoms stabilize for a period of time, abruptly worsen, and then stabilize again). One exception to this is when a series of small strokes occur that reduce blood flow to the brain; these can have a cumulative effect, destroying brain tissue a little at a time and producing symptoms that gradually surface. Vascular dementia also is sometimes characterized by hallucinations, restlessness, and loss of bladder control.
Are you at risk for vascular dementia?
If you have any of the risk factors for a stroke, you have an increased likelihood of developing vascular dementia after a stroke. Even so, dementia doesn’t affect all stroke patients, and researchers have been able to identify the risk factors that help predict who is most susceptible for vascular dementia.
Age is a strong predictor of post stroke dementia. In one study, stroke patients age 80 and older had a 13-fold increased chance of dementia, compared to those age 60–69.
Your mental abilities before a stroke may be a more important factor than age. People who score poorly on cognitive tests prior to a stroke are more likely to experience mental impairment after a stroke.
Limited education has been associated with a higher incidence of vascular dementia. In one report, people with eight or fewer years of education had four times the risk of having post stroke dementia than people with 13 or more years of education. The authors of this study hypothesized that individuals with more education may have greater “cognitive reserve,” enabling them to do better on cognitive tests despite their impairment.
Blacks and Hispanics are more likely to develop post-stroke dementia than whites. This racial difference may be related to access to quality healthcare and to educational opportunities. The location of the brain injury caused by a stroke can influence vulnerability to dementia. Strokes that affect the left side of the brain have a greater risk of dementia than those affecting the right side. (The left hemisphere of the brain may be more responsible for general cognitive function than the right hemisphere). Also, when a stroke produces aphasia (loss of language ability), it is more likely to lead to dementia.
Other risk factors for vascular dementia include having high blood pressure or diabetes, engaging in too little physical activity, and being a smoker.
What you and your doctor can do
If you’ve had a stroke, you should see your doctor on a regular basis to monitor your recovery. If vascular dementia is diagnosed, the bad news is that it is not curable. However, researchers are studying ways to slow the progression of vascular dementia. One promising treatment are the drugs used to slow memory loss in Alzheimer’s patients. Although not FDA-approved for vascular dementia, researchers at the University of Toronto presented a study at the World Stroke Congress in 2004 that examined data from more than 1,200 patients with vascular dementia, who were treated with the Alzheimer’s drug Aricept (donepezil) or a placebo. In one of their analyses, Aricept was associated with modest but significant improvements in the ability to perform day-to-day tasks. At this point, however, Alzheimer’s drugs are not widely prescribed for vascular dementia patients outside of clinical trials.
Taking a daily aspirin tablet, controlling high blood pressure, and lowering cholesterol levels also show promise in slowing memory loss. Until research confirms the value of these treatments, doctors recommend that you adopt as healthy a lifestyle as possible -- exercise regularly, eat balanced meals, and stop smoking. If you have high blood pressure, diabetes, or other chronic diseases, make sure they’re being properly managed with medications or lifestyle changes. By doing this, you may be able to reduce your chances of having a stroke and developing dementia afterward. When it comes to a stroke and its consequences (such as dementia), preventing a stroke in the first place is your best option.
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