Vascular dementia

Vascular dementia is the medical term for forms of dementia that are caused by circulatory disorders of the brain. The term “vascular” is derived from the Latin word “vasculum”, meaning vase or small vessel. Vascular dementia is among the most common types of dementia alongside Alzheimer’s disease.

However, it is often very difficult to distinguish between Alzheimer’s disease and vascular dementia as many patients have symptoms associated with both conditions. This is referred to as mixed dementia and particularly affects patients at high age.

The symptoms of vascular dementia can differ greatly depending on the areas of the brain affected by the circulatory disorders. The most common type of vascular dementia, which is linked to problems with small blood vessels in the brain, has the following characteristic symptoms:

• slowed thought processes
• trouble concentrating and paying attention
• forgetfulness
• apathy
• rapid mental and physical exhaustion

Progressive memory loss is not as significant a symptom as with Alzheimer’s disease. The following physical symptoms often occur as well:

• unsteady gait
• loss of bladder control (increased urinary urgency, incontinence)
• difficulty swallowing and speaking
• baseless laughter and crying
• feeling faint

If larger areas of the brain are affected by a reduced flow of blood, more brain tissue is lost and additional neurological symptoms such as paralysis, numbness and visual impairment are also possible.

Dementia generally causes a progressive reduction, and ultimately the complete loss, of a patient’s mental capacities, specifically:

• short-term and retentive memory
• long-term memory
• concentration and ability to pay attention
• understanding and judgment
• place and time orientation
• planning and controlling activities
• drive
• language
• behavior
• mood and emotional state

These progressive symptoms make it increasingly difficult for patients to perform everyday activities and live independently. As the disease reaches an advanced stage, they need support during their everyday lives and ultimately full-time care.

The symptoms alone do not clearly indicate the type of dementia. As many patients have both Alzheimer’s disease and circulatory disorders, the symptoms overlap a great deal.

Vascular dementia is not a clear-cut disease. It can be caused by various changes to the blood vessels and cardiovascular system. In all cases though, several small areas of the brain receive an insufficient oxygen supply.

The most common cause of vascular dementia is cerebral microangiopathy, a disorder that affects the small blood vessels in the brain. The blood vessels that feed the brain become so constricted due to deposits and thickened walls that lower areas of the cerebrum no longer receive enough blood. This form of ischemia (insufficient blood supply) can progress slowly and spread. However, it can also cause one or more minor strokes.

Vascular dementia can also be caused by blood clots, which can block the blood vessels that supply the brain. The sudden closure of the feeding blood vessel kills off the downstream brain tissue (cerebral infarction). These blood clots can not only develop on deposits (arteriosclerosis) in the brain vessels themselves but are also often carried into the brain from the carotid artery or heart. In the case of very minor cerebral infarctions, the typical stroke symptoms are not necessarily noticeable.

If multiple cerebral infarctions occur in different areas and lead to vascular dementia, this is referred to as multi-infarct dementia. However, dementia can also be triggered by a single cerebral infarction if it affects a strategically important area for mental performance (strategic infarct dementia). If a larger artery is blocked by a blood clot, a larger area of the downstream brain tissue is also lost. About a quarter of patients who experience this type of stroke subsequently develop dementia.

On far rarer occasions, vascular dementia is caused by bleeding in the brain. Such “hemorrhagic strokes” usually occur if feeding blood vessels are damaged by years of high blood pressure and rupture.

Old age and high blood pressure are the main risk factors for vascular dementia. About 25% of people who have had a stroke later develop dementia. The same risk factors that increase the likelihood of a stroke or other cardiovascular diseases also increase the probability of vascular dementia.

These primarily include conditions such as:

• high blood pressure (hypertension)
• diabetes mellitus
• increased cholesterol levels (hypercholesterolemia)

The risk of stroke and vascular dementia is also increased by heart conditions such as atrial fibrillations and coronary heart disease.

An unhealthy lifestyle is another risk factor. The following behavioral habits have a particularly negative impact:

• smoking
• lack of physical exercise
• poor diet
• being overweight and obesity (adiposity)
• high levels of alcohol consumption

Vascular dementia is the second most common type of dementia after Alzheimer’s disease. Around 250,000 people develop dementia every year in Germany, with vascular dementia accounting for 15 to 25% of these cases. Women are affected slightly more often than men.

Vascular dementia can have various symptoms depending on the causes of the circulatory disorder and the parts of the brain it affects. The way in which the dementia progresses can therefore vary widely.

In the case of a reduced blood flow to the small blood vessels in the brain (microangiopathy), the loss of mental performance is progressive. If vascular dementia is caused by individual cerebral infarctions, it can sometimes only progress to a certain point and may even improve slightly. In the case of repeated strokes, gradual deterioration is also possible.

Due to the related cardiovascular diseases, vascular dementia patients usually die quicker than people with Alzheimer’s disease. The average period between diagnosis and death is between three and five years.

As treatment for the risk factors and underlying conditions is ever improving, the number of people with vascular dementia is falling.

A healthy lifestyle and the consistent treatment of conditions such as high blood pressure are important factors in reducing the risk of vascular dementia.

Scientific studies have shown that these measures are also effective in preventing Alzheimer’s disease.

The following measures seem to have the greatest effect:

• regular physical exercise
• not smoking
• healthy eating

In addition, a good education, an active social life involving everyday activities with others, an active mind and continuous mental challenges during everyday life can also help to prevent a premature loss of mental capacities.

Doctors use a range of different methods to obtain as accurate a diagnosis as possible in the event of suspected dementia:

Neuropsychological tests

Neuropsychological tests can be used to determine whether and to what extent certain areas of mental performance (e.g. memory or the ability to concentrate) are impaired. The performance can be measured in numerical values. The doctor then compares these with values taken from the general population.

The neuropsychological examination has two objectives. Firstly, the subjective feeling of a reduction in mental capacity can be transformed into an objective comparative value. This therefore shows whether or not the perceived impairments actually exist. Secondly, it is possible to determine the combination of symptoms present in the case at hand. These give important indications as to the cause of the dementia.

Imaging techniques

The brain is also examined using radiological procedures. Examining cross-sectional images of the brain makes it possible to detect chronic circulatory disorders and previous cerebral infarctions or hemorrhages. Such scans are performed using computed tomography (CT) and magnetic resonance imaging (MRI). Ultrasound scans of the neck arteries and special CT and MRI scans of the cerebral arteries are used to detect constrictions that cause circulatory disorders in the brain.

Cardiovascular function tests

In addition, blood and blood pressure tests are performed to detect high-risk conditions such as high blood pressure, diabetes mellitus and high cholesterol. A long-term electrocardiogram (ECG) is also used to detect issues such as atrial fibrillation. An ultrasound examination of the heart (echocardiography) can indicate problems with the heart valves or muscle.

As vascular dementia is caused by circulatory disorders, it is particularly important to treat underlying high-risk conditions. This reduces the risk of even more brain tissue dying.

Treating high-risk conditions

High blood pressure, diabetes mellitus and high cholesterol levels can be successfully treated with medication. Heart conditions such as atrial fibrillation, coronary heart disease or heart failure can also be treated with appropriate measures.

If blood clots have formed in the brain, patients are given anti-clotting medication. This helps prevent further strokes. If a constricted carotid artery is the cause, the constriction can be eliminated through surgery.

Other medication

Alzheimer’s disease can be treated with drugs that can sometimes alleviate the symptoms. These include cholinesterase inhibitors and memantine. However, these drugs only work temporarily and do not affect the progression of the disease. They are not effective in relation to vascular dementia and can also cause side effects. As such, they should not be used to treat purely vascular dementia.

If necessary, doctors prescribe psychotropic medication to relieve symptoms such as delirium, fear, irritability, restlessness, sleep disorders and depression.

At present, there is no known medical treatment that can significantly influence the progression of dementia and no cure for this disease. This applies to both Alzheimer’s disease and vascular dementia.

Non-medical concomitant treatments

People with dementia usually require long-term care and support. This can involve multiple specialists from the fields of medicine, care, occupational therapy, physiotherapy and social work. Family carers should also be well informed and supported.

There is a short guide published by the German Agency for Quality in Medicine (Ärztliches Zentrum für Qualität in der Medizin) on the topic Demenz: eine Herausforderung für Angehörige (dementia: a challenge for loved ones).

The Federal Ministry of Health website provides an online guide on dementia with information for patients and their loved ones.

Further information:

• Short guide of the German Agency for Quality in Medicine (Ärztliches Zentrum für Qualität in der Medizin) on dementia: more than just forgetful
• German Alzheimer’s Society (Deutsche Alzheimer Gesellschaft e.V.) Selbsthilfe Demenz (self-help for dementia)