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 also can 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 high blood pressure, high cholesterol and smoking — also raise your vascular dementia risk. Controlling these factors can help lower your chances of developing vascular dementia.
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.
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.
Another characteristic pattern of vascular dementia symptoms sometimes follows a series of strokes or mini strokes. In this pattern, 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.
But vascular dementia can also develop very gradually, just like Alzheimer's disease. What's more, vascular dementia and Alzheimer's often occur together.
Studies show that people with dementia symptoms usually have brain changes typical of more than one type. Some doctors call this condition mixed dementia.
Vascular dementia symptoms include:
- 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
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:
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 brain infarctions" still increase dementia risk.
With both silent and apparent strokes, the risk of vascular dementia increases with the number of infarctions 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; hardening of the arteries; diabetes; lupus erythematosus; brain hemorrhage; and temporal arteritis.
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 for vascular dementia rises as you grow older. The disorder is rare before age 65, and risk rises substantially as you reach your 80s and 90s.
- History of heart attack, strokes or mini strokes. 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 mini stroke (transient ischemic attack) may increase your risk of developing dementia.
- 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 — and possibly your risk of Alzheimer's disease — by reducing the flow of blood that nourishes your brain.
- High cholesterol. Elevated levels of low-density lipoprotein (LDL), the so-called "bad" cholesterol, are associated with an increased risk of vascular dementia, and possibly with a higher risk of Alzheimer's disease.
- 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 by leading to poor blood flow to your brain and elsewhere in your body.
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.
- Keep your cholesterol in check. A healthy, low-fat diet and cholesterol-lowering medications if you need them may reduce your risk of vascular dementia, probably by reducing the amount of plaque deposits building up inside your brain's arteries.
- Prevent or control diabetes. Avoiding the onset of diabetes, with diet and exercise, is another possible way to decrease your risk of dementia. If you already have diabetes, controlling your glucose levels can 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.