Vascular dementia: Description
Vascular dementia is caused by a disturbed blood supply to the brain tissue. Depending on the mechanism of this circulatory disorder, doctors differentiate between various forms of vascular dementia. For example, there is multi-infarct dementia, which is caused by several small cerebral infarcts (ischemic strokes). Other forms include subcortical vascular dementia and mixed (cortical and subcortical) vascular dementia.
Vascular dementia accounts for around ten to 15 percent of all dementias. Mixed forms of vascular and Alzheimer’s dementia account for a further 20 percent or so.
Vascular dementia: symptoms
Vascular dementia is also associated with focal neurological deficits (caused by the cerebral infarcts): For example, hemiplegia, gait disturbance and increased muscle reflexes can occur. Bladder emptying disorders (micturition disorders) in the form of a compulsive (imperative) urge to urinate or incontinence are also possible.
Personality and social behavior are not affected by vascular dementia. Memory performance is often only slightly affected by the disease – in contrast to Alzheimer’s, the most common form of dementia.
Vascular dementia: causes and risk factors
Vascular dementia is caused by reduced blood flow in the brain (cerebral ischemia), which causes nerve cells to die. Various mechanisms can trigger such ischemia:
In other cases, vascular dementia is caused by a single, sometimes only small infarct at a strategically important location (such as the thalamus), which leads to an interruption of pathways. Doctors refer to this as “strategic infarct dementia”.
The circulatory disorder can also be caused by a thickening of the walls of small blood vessels that supply blood to deeper areas of the brain. This results in small infarcts (lacunae) and damage to nerve fibers (medullary damage). Doctors refer to this as subcortical vascular encephalopathy (SVE).
In some patients, vascular dementia is the result of minor or major cerebral hemorrhages (the second largest group of strokes after cerebral infarctions). This is referred to as “haemorrhagic dementia”.
Vascular dementia: risk factors
Various factors favor vascular dementia. These include, for example, high blood pressure, heart disease, diabetes mellitus (diabetes), high cholesterol levels, obesity, lack of exercise and smoking.
Vascular dementia: diagnosis
If vascular dementia (or another type of dementia) is suspected, the doctor will first take the patient’s medical history (anamnesis) in conversation with the patient and often also with relatives:
He will ask the patient to describe their symptoms and ask about current or previous illnesses such as cardiovascular disease, cerebrovascular disease, high blood pressure, elevated blood lipid levels and diabetes. He also asks about the patient’s nicotine and alcohol consumption. In addition, the doctor will ask to what extent the patient is physically active and whether they are taking any medication.
Physical examination
Neuropsychological examination
The neuropsychological examination is also particularly important for the diagnosis of vascular dementia. Various tests are carried out to assess the brain performance disorder (“dementia tests” such as the clock test, MMST and DemTect). However, such deficits are very inconsistent in vascular dementia.
Imaging
Imaging examinations such as computed tomography (CT) and magnetic resonance imaging (MRI) are important to rule out other causes of the symptoms. These can be brain tumors, cerebral hemorrhages or hydrocephalus, for example. Characteristic tissue changes can also indicate which vascular dementia variant is present, for example multi-infarct dementia or dementia as a result of an infarction in important brain circuits (strategic infarction).
Laboratory tests
If vascular dementia is suspected, a blood sample from the patient is also routinely examined. Parameters such as blood salts (electrolytes), blood sugar and liver values are important in order to identify risk factors for vascular damage that can be treated medically. Blood tests can also be used to identify other causes of dementia (such as hypothyroidism or liver dysfunction).
If the findings remain inconclusive, a sample of cerebrospinal fluid (CSF) is taken from the spinal column (lumbar puncture) and examined in the laboratory. In this way, for example, inflammatory or immunological diseases of the brain can be ruled out as the cause of the symptoms.
Genetic tests
Vascular dementia: Therapy
Vascular dementia cannot be treated causally. However, various therapeutic measures can be used to try to alleviate the symptoms.
Medication
There are no drugs that have been approved for vascular dementia itself and whose effectiveness has been scientifically proven. In individual cases, however, medication is given to treat the psychiatric symptoms. Such preparations have no specific approval for vascular dementia and are therefore used off-label.
Sometimes so-called acetylcholinesterase inhibitors and memantine are helpful in vascular dementia. These drugs are mainly used as anti-dementia drugs for Alzheimer’s disease.
There is also evidence that a certain extract from ginkgo leaves (Ginkgo biloba EGb761) is effective in vascular dementia.
Non-drug treatment
Vascular dementia – like other forms of dementia – should also be treated in a non-pharmacological way. For example, cognitive training, occupational therapy, music and dance therapy can be useful for dementia. If gait is unsteady, those affected should be given walking aids and regular gait training. If there are problems with continence, consistent toilet training is advisable, among other things.
Non-pharmacological measures are also important for vascular risk factors and underlying diseases. For example, the doctor will recommend that the patient stop smoking in future and change their diet (less animal fats, more vegetable fats, etc.).
Vascular dementia: progression and prognosis
The course of the disease (as well as the symptoms) is also influenced by the fact that it is not always purely vascular dementia. Patients often suffer from a mixed form, for example Alzheimer’s dementia plus vascular dementia. Life expectancy and progression can then hardly be predicted.
In general, the life expectancy of patients is shortened in many cases. Vascular dementia patients often die from illnesses such as pneumonia, stroke or acute circulatory disorders of the heart (acute coronary syndrome = overarching term for heart attack and unstable angina pectoris).
