What is vascular dementia?
Vascular dementia (VaD), also called multi-infarct dementia, occurs when the cells in the brain are deprived of oxygen. A network of blood vessels called the vascular system supplies the brain with oxygen. If there is a blockage in the vascular system, or if it is diseased, blood is prevented from reaching the brain. As a result, cells in the brain die, leading to the symptoms of dementia. After Alzheimer's disease, VaD is the second leading form of dementia, accounting for up to 20 per cent of all cases.
When Alzheimer's disease and VaD occur at the same time, the condition is called "mixed dementia".
How does vascular dementia affect the person?
Stroke and vascular dementia
Stroke is a common cause of VaD. A stroke occurs when blood flow in the brain is blocked or a blood vessel bleeds, preventing the blood from flowing properly through the vessel. When this happens, the brain cells cannot get oxygen and they die. Strokes can be large or small, and can have a cumulative effect, which means each stroke adds more to the problem. Strokes can affect how a person can walk, and cause weakness in an arm or leg, slurred speech or emotional outbursts. The difficulties the person has depend on the part of the brain that did not get the oxygen.
Vascular dementia usually comes on suddenly. Difficulties may happen in steps. Sometimes, the person’s abilities may deteriorate for a while and then stand still for a time. Then, they may deteriorate again. The cognitive symptoms, the ability to think, may change, affecting some areas of the brain more or less than others (e.g., the areas that control language, vision or memory). Urinary difficulties (difficulty going to the bathroom) are common in people who have VaD.
Binswanger's disease is a rare form of VaD that is caused by damage to blood vessels deep in the brain's "white matter." High blood pressure plays an important role in Binswanger's disease.
How is vascular dementia assessed?
If VaD is suspected, the doctor will often order scans of the brain in order to check for blockages or narrowing of blood vessels in the brain.
What are the risk factors for vascular dementia?
Both men and women can be affected by vascular dementia. Risk factors include:
- Being older than 65
- Having high blood pressure (hypertension)
- Having heart disease
- Having diabetes
Smoking, being overweight, having high cholesterol levels and having a family history of heart problems may also increase the risk of having stroke, which increases the risk of vascular dementia. Mini-strokes (sometimes called transient ischemic attacks or TIAs) are warning signs that a stroke may come. Losing vision, speech or strength temporarily, or having short episodes of numbness may mean someone is having a TIA.
Routine brain scans in a group of middle-aged people showed that 10 per cent of them had had a stroke but did not know about it. Having the stroke, even if they did not know, raised their risk for more strokes and memory loss. These silent cerebral infarctions (SCIs, or silent strokes) are caused by a blood clot that blocks the blood flow to the brain. Many times, silent strokes are considered to make up a risk factor for vascular dementia. People with atrial fibrillation, the most common type of irregular heart beat in people over 65, have more than twice the normal rate of these silent strokes.
Knowing the risk factors for vascular dementia is important because often they may be treated, to reduce the risk of having a stroke. Risk factors can be reduced by adopting a healthy lifestyle that includes regular physical activity, eating well, avoiding smoking and reducing stress. Medications can control high blood pressure, diabetes and heart disease.
Is there treatment?
After a person has a stroke, medication may be prescribed to improve blood flow to the brain and reduce the risk of further stroke. A person may also benefit from different therapies to help with movement and speech, such as physiotherapy, occupational therapy or speech therapy. Aside from the treatment of the underlying causes of vascular dementia such as hypertension, high cholesterol and diabetes, some physicians routinely recommend the use of medications called cholinesterase inhibitors.
For more information:
- Call your local Alzheimer Society or visit the We can help section of our website.
- Visit the Heart and Stroke Foundation website
- Mayo clinic
- Alzheimer's Society (UK); "Understanding Vascular Dementia"
- Webinar on vascular dementia presented by BrainXchange.
Last Updated: 11/08/2017