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Vascular dementia is a general term describing problems with reasoning, planning, judgment, memory and other thought processes caused by brain damage from impaired blood flow to your brain.
You can develop vascular dementia after a stroke blocks an artery in your brain, but strokes don't always cause vascular dementia. Whether a stroke affects your thinking and reasoning depends on your stroke's severity and location. Vascular dementia can also result from other conditions that damage blood vessels and reduce circulation, depriving your brain of vital oxygen and nutrients.
Factors that increase your risk of heart disease and stroke — including diabetes, high blood pressure, high cholesterol and smoking — also raise your vascular dementia risk. Controlling these factors may help lower your chances of developing vascular dementia.
Symptoms
Vascular dementia symptoms vary, depending on the part of your brain where blood flow is impaired. Symptoms often overlap with those of other types of dementia, especially Alzheimer's disease dementia.
Vascular dementia signs and symptoms include:
- • Confusion
- • Trouble paying attention and concentrating
- • Reduced ability to organize thoughts or actions
- • Decline in ability to analyze a situation, develop an effective plan and communicate that plan to others
- • Difficulty deciding what to do next
- • Problems with memory
- • Restlessness and agitation
- • Unsteady gait
- • Sudden or frequent urge to urinate or inability to control passing urine
- • Depression or apathy
Vascular dementia symptoms may be most clear-cut when they occur suddenly following a stroke. When changes in your thinking and reasoning seem clearly linked to a stroke, this condition is sometimes called post-stroke dementia.
Sometimes a characteristic pattern of vascular dementia symptoms follows a series of strokes or ministrokes. Changes in your thought processes occur in noticeable steps downward from your previous level of function, unlike the gradual, steady decline that typically occurs in Alzheimer's disease dementia.
But vascular dementia can also develop very gradually, just like Alzheimer's disease dementia. What's more, vascular disease and Alzheimer's disease often occur together.
Studies show that many people with dementia and evidence of brain vascular disease also have Alzheimer's disease.
Causes
Vascular dementia results from conditions that damage your brain's blood vessels, reducing their ability to supply your brain with the amounts of nutrition and oxygen it needs to perform thought processes effectively.
Common conditions that may lead to vascular dementia include:
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Stroke (infarction) blocking a brain artery. Strokes that block a brain artery usually cause a range of symptoms that may include vascular dementia. But some strokes don't cause any noticeable symptoms. These silent strokes still increase dementia risk.
With both silent and apparent strokes, the risk of vascular dementia increases with the number of strokes that occur over time. One type of vascular dementia involving many strokes is called multi-infarct dementia.
- Narrowed or chronically damaged brain blood vessels. Conditions that narrow or inflict long-term damage on your brain blood vessels also can lead to vascular dementia. These conditions include the wear and tear associated with aging, high blood pressure, abnormal aging of blood vessels (atherosclerosis), diabetes, and brain hemorrhage.
Risk factors
In general, the risk factors for vascular dementia are the same as those for heart disease and stroke. Risk factors for vascular dementia include:
- Increasing age. Your risk of vascular dementia rises as you grow older. The disorder is rare before age 65, and the risk rises substantially by your 90s.
- History of heart attack, strokes or ministrokes. If you've had a heart attack, you may be at increased risk of having blood vessel problems in your brain. The brain damage that occurs with a stroke or a ministroke (transient ischemic attack) may increase your risk of developing dementia.
- Abnormal aging of blood vessels (atherosclerosis). This condition occurs when deposits of cholesterol and other substances (plaques) build up in your arteries and narrow your blood vessels. Atherosclerosis can increase your risk of vascular dementia by reducing the flow of blood that nourishes your brain.
- High cholesterol. Elevated levels of low-density lipoprotein (LDL), the "bad" cholesterol, are associated with an increased risk of vascular dementia.
- High blood pressure. When your blood pressure's too high, it puts extra stress on blood vessels everywhere in your body, including your brain. This increases the risk of vascular problems in the brain.
- Diabetes. High glucose levels damage blood vessels throughout your body. Damage in brain blood vessels can increase your risk of stroke and vascular dementia.
- Smoking. Smoking directly damages your blood vessels, increasing your risk of atherosclerosis and other circulatory diseases, including vascular dementia.
- Obesity. Being overweight is a well-known risk factor for vascular diseases in general, and therefore, presumably increases your risk of vascular dementia.
- Atrial fibrillation. In this abnormal heart rhythm, the upper chambers of your heart begin to beat rapidly and irregularly, out of coordination with your heart's lower chambers. Atrial fibrillation increases your risk of stroke because it causes blood clots to form in the heart that can break off and go to the brain blood vessels.
Prevention
The health of your brain's blood vessels is closely linked to your overall heart health. Taking these steps to keep your heart healthy may also help reduce your risk of vascular dementia:
- Maintain a healthy blood pressure. Keeping your blood pressure in the normal range may help prevent both vascular dementia and Alzheimer's disease.
- Prevent or control diabetes. Avoiding the onset of type 2 diabetes, with diet and exercise, is another possible way to decrease your risk of dementia. If you already have diabetes, controlling your glucose levels may help protect your brain blood vessels from damage.
- Quit smoking. Smoking tobacco damages blood vessels everywhere in your body.
- Get physical exercise. Regular physical activity should be a key part of everyone's wellness plan. In addition to all of its other benefits, exercise may help you avoid vascular dementia.
- Keep your cholesterol in check. A healthy, low-fat diet and cholesterol-lowering medications if you need them may reduce your risk of strokes and heart attacks that could lead to vascular dementia, probably by reducing the amount of plaque deposits building up inside your brain's arteries.
Diagnosis
Doctors can nearly always determine that you have dementia, but there's no specific test that confirms you have vascular dementia. Your doctor will make a judgment about whether vascular dementia is the most likely cause of your symptoms based on the information you provide, your medical history for stroke or disorders of the heart and blood vessels, and results of tests that may help clarify your diagnosis.
Lab tests
If your medical record doesn't include recent values for key indicators of the health of your heart and blood vessels, your doctor will test your:
- • Blood pressure
- • Cholesterol
- • Blood sugar
He or she may also order tests to rule out other potential causes of memory loss and confusion, such as:
- • Thyroid disorders
- • Vitamin deficiencies
Neurological exam
Your doctor is likely to check your overall neurological health by testing your:
- • Reflexes
- • Muscle tone and strength, and how strength on one side of your body compares with the other side
- • Ability to get up from a chair and walk across the room
- • Sense of touch and sight
- • Coordination
- • Balance
Brain imaging
Images of your brain can pinpoint visible abnormalities caused by strokes, blood vessel diseases, tumors or trauma that may cause changes in thinking and reasoning. A brain-imaging study can help your doctor zero in on more likely causes for your symptoms and rule out other causes.
Brain-imaging procedures your doctor may recommend to help diagnose vascular dementia include:
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Computerized tomography (CT) scan. For a CT scan, you'll lie on a narrow table that slides into a small chamber. X-rays pass through your body from various angles, and a computer uses this information to create detailed cross-sectional images (slices) of your brain.
A CT scan can provide information about your brain's structure; tell whether any regions show shrinkage; and detect evidence of strokes, ministrokes (transient ischemic attacks), blood vessel changes or tumors. Sometimes you'll receive an intravenous (IV) injection of a contrast agent that will help highlight certain brain tissues.
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Magnetic resonance imaging (MRI). An MRI uses radio waves and a strong magnetic field to produce detailed images of your brain. You lie on a narrow table that slides into a tube-shaped MRI machine, which makes loud banging noises while it produces images.
MRIs are painless, but some people feel claustrophobic inside the machine and are disturbed by the noise. MRIs are generally the preferred imaging test because MRI can provide even more detail than CT scans about strokes, ministrokes and blood vessel abnormalities.
Carotid ultrasound
This procedure uses high-frequency sound waves to determine whether your carotid arteries — which run up through either side of your neck to supply blood to the brain — show signs of narrowing as a result of plaque deposits or structural problems. Your test may include a Doppler ultrasound, which shows the movement of blood through your arteries in addition to structural features.
Neuropsychological tests
This type of exam assesses your ability to:
- • Speak, write and understand language
- • Work with numbers
- • Learn and remember information
- • Develop a plan of attack and solve a problem
- • Respond effectively to hypothetical situations
Neuropsychological tests sometimes show characteristic results for people with different types of dementia. People with vascular dementia may have an exceptionally hard time analyzing a problem and developing an effective solution.
They may be less likely to have trouble learning new information and remembering than are people with dementia due to Alzheimer's disease unless their blood vessel problems affect specific brain regions important for memory. However, there's often a lot of overlap in exam results for people with vascular dementia and people who also have the brain changes of Alzheimer's disease.
Treatment
Treatment often focuses on managing the health conditions and risk factors that contribute to vascular dementia.
Controlling conditions that affect the underlying health of your heart and blood vessels can sometimes slow the rate at which vascular dementia gets worse, and may also sometimes prevent further decline. Depending on your individual situation, your doctor may prescribe medications to:
- • Lower your blood pressure
- • Reduce your cholesterol level
- • Prevent your blood from clotting and keep your arteries clear
- • Help control your blood sugar if you have diabetes