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Stroke – a Medical Emergency
The occurrence of a stroke is an emergency situation. You have to act immediately without any hesitation or waiting. In many cases, fast action can minimize the consequences of a stroke.
If someone around you shows any signs of stroke then dial 112 (the European emergency number) to reach the emergency services and fire brigade. That is the fastest way for the patient to arrive at the emergency department of the nearest hospital with adequate know-how and equipment, meaning a Stroke Unit. Even if the symptoms are transitory and disappear quickly, they are an important warning sign and should be medically dealt with immediately. A transitory ischemic attack is often the herald of an impending stroke.
What is a stroke?
A stroke occurs when the blood flow in the brain is suddenly disturbed. As a consequence the nerve cells in the brain are starved of oxygen and nutrients, and they die if blood flow is not re-established. Other terms for a stroke are apoplexy, brain insult or cerebral infarction.
The stroke may be caused by an obstruction (termed ischemic stroke) or rupture (hemorrhagic stroke) of a blood vessel.
Computed tomography (CT)
A computed tomography (CT) of the head in the acute phase of stroke can help the physician to find out whether the stroke is caused by bleeding or by a vascular occlusion (ischemia). Due to its wide availability CT is the standard in the diagnosis of acute stroke. The simple native CT in acute stroke is now supplemented in many hospitals by vascular imaging with CT (CT angiography) and measurement of blood circulation (perfusion CT). These techniques allow more detailed examinations to detect which blood vessel is sealed and the extent to which the brain tissue is affected by the reduced blood flow.
Magnetic resonance imaging (MRI)
In specialized centers, magnetic resonance imaging (MRI) is carried out instead of or in addition to CT. MRI can provide more useful information about the causes and course of tissue damage in stroke. In addition, so-called lacunar infarcts, older infarctions or additional damage (for example cerebral microangiopathy of the brain) can be shown much better with MRI. MRI can also image the vessels (MR angiography) and blood flow (perfusion). Unlike CT, MRI does not work with X-rays, but with a magnetic field. Examinations can therefore theoretically be repeated numerous times without negative long-term consequences for the patient. Patients with a pacemaker or other metal parts in the body may not be examined.
Doppler and Duplex Sonography
Doppler and duplex sonography can detect, calcification, atherosclerotic deposits, narrowed blood vessels and thrombotic occlusions in the cerebral arteries. The greater the obstruction of a neck vessel, the greater the risk of stroke. With the so-called transcranial Doppler and duplex sonography even vessels within the head can be shown.
Arrhythmia can be detected with a simple ECG (electrocardiogram) and with a long-term or 24-hour ECG. Certain arrhythmias (e.g. atrial fibrillation) can cause small blood clots to form which are washed into the brain and can obstruct a vessel (embolism). Often the physician can already suspect arrhythmias when he feels the patient's pulse or listens to the patient’s heart.
Ultrasound of the Heart
With these examinations, heart function and can be described and any dangerous blood clots in the heart cavities detected. The ultrasound can be carried out from the outside through the chest (transthoracic echocardiography, TTE) or from the esophagus (transesophageal echocardiography, TEE). The latter is indeed unpleasant, but images the more relevant part of the heart with respect to possible sources of embolisms.
To reduce the damage a stroke causes in the brain and to improve the chances of a complete recovery of brain functions, diagnosis and treatment should start as early as possible. The treatment options depend on the type of stroke. The attending physician has to adjust the patient’s treatment individually.
In the acute phase of stroke, intensive medical treatment focuses on four principles:
Recanalization of Vascular Occlusions
If the stroke is caused by a blood clot blocking a blood vessel, the clot can in some cases be dissolved with a drug (so-called thrombolysis). The drug is injected through a blood vessel into the blood stream. The treatment is carried out in highly specialized hospitals and is approved only within the first four-and-a-half hours (4,5h) after stroke onset. But in any case: the sooner the lyses, the greater the success.
Preventing Stroke Recurrence
A patient who has suffered a stroke has an increased risk of suffering another stroke. Even if the first stroke had little impact, the damage by a following stroke may be large. Therefore, a thorough examination to determine the cause of stroke is always advisable. Ususally the doctor will prescribe a blood thinning drug to reduce the risk of recurrence.
Minimization of Secondary Damages
When the brain swells as a result of a stroke, and further swelling is hindered by the skull bone, it may be necessary to remove a piece of bone to give the brain space for further expansion.
There are hospitals with special wards for the treatment of stroke. These facilities are called stroke units. Reasons for stroke unit admission:
- a fresh stroke which occurred in the last 72 h
- a deterioration of the patient’s condition
- unstable vital signs with problems of blood pressure, heart rhythm, body temperature and blood sugar levels
- the possibility of carrying out a re-opening of vessel occlusion
Patients who are so severely affected that they fall into a coma or require ventilation should not be treated in a stroke unit, but rather in an ICU.
In principle, anyone can suffer a stroke – whether he or she is young or old. Stroke is not a disease that affects only "old people". Every fourth person affected is of working age, an estimated 5 % of whom are even younger than 40.
Moreover, people whose relatives have suffered a stroke carry an increased risk of suffering a stroke. Certain risk factors are hereditary. Age and genetic predisposition are risk factors that cannot be influenced, but others can be changed or treated.
High Blood Pressure
High blood pressure is also called arterial hypertension. Arterial hypertension is defined as a permanent increase of systolic and diastolic blood pressure (maximum and minimum blood pressure value).
Increased values measured once or occasionally do not necessarily mean a high blood pressure. For diagnosis, regularly increased measurement values are crucial. The optimum blood pressure is 120/80 mm Hg (according to the target values set by WHO). The limit for arterial hypertension for adults is 140/90 mm Hg. Hypertension values vary heavily:
- moderate hypertension: values are permanently above 160/100 mm Hg
- severe hypertension: values are permanently above 180/110 mm Hg
High blood pressure is a major risk factor for stroke. It leads to thickening and stiffening of the blood vessels (arteriosclerosis). Patients with high blood pressure therefore suffer a stroke more often than people without high blood pressure. High blood pressure increases the relative risk of suffering a stroke six- to eight-fold compared to a person without hypertension. The level plays a special role, because with the level of blood pressure, the risk of stroke increases. Treatment of high blood pressure, however, leads in turn to a significant risk reduction compared to untreated patients.
A major problem is that high blood pressure is still too rarely recognized. Usually the person concerned does not notice high blood pressure because it does not hurt. It is therefore important to check blood pressure regularly and initiate treatment if necessary. Everyone should know his or her blood pressure.
Cigarette smoking is a significant risk factor for stroke, and risk increases with the number of cigarettes smoked per day and in total over the number of years. Smokers have a relative stroke risk 1.5 to 2 times higher than non-smokers. The negative effects of smoking are manifold:
- Smoking fosters the calcification of blood vessels (atherosclerosis).
- Smoking causes the nervous system to release the stress hormones adrenaline and noradrenaline, thereby narrowing the blood vessels. This in turn leads to high blood pressure. The constriction of blood vessels limits the intake of vital substances.
- Smoking also reduces the amount of oxygen which is transported by the red blood cells in the body. The amount of oxygen available to the brain (and other parts and other parts of the body) decreases. Due to oxygen deficiency the brain signals the bone marrow to produce more red blood cells. The increased production of red blood cells leads to "blood thickening" and blood flow properties are affected; the blood is thicker. This reduces the blood flow in addition to the constricted vessels.
- Smoking increases the tendency of the blood to coagulate. This increases the risk of clot formation in the blood.
- Finally, smoking leads to alterations of fat metabolism.
Therefore please quit smoking! When you stop cigarette smoking your stroke risk factor is reduced considerably.
Alterations of Fat Metabolism
Alterations of fat metabolism increase the risk of stroke. Blood fats are deposited in the artery walls and enhance the development of artheriosclerosis.
Pay attention particularly to cholesterol, because with total-cholesterol levels above 240 mg/dl the risk of stroke increases by two-and-a-half times. The total-cholesterol level should be less than 200 mg/dl. This approximate value is particularly important if the "bad" part of the cholesterol (low density lipoprotein/LDL) is increased and the "good" part of the cholesterol (high density lipoprotein/HDL) is reduced.
Everyone should know their cholesterol level and, if necessary, deal with it by making changes in diet or medication. Diet has a major impact on cholesterol levels. As a guideline, the consumption of animal fats should be restricted or replaced by vegetable fats. Sports and regular exercise also have a positive effect on blood lipid levels.
Smoking, on the other hand, has negative effects on blood lipid levels.
Obesity and Lack of Exercise
What is referred to as "fat" or "skinny" is often determined by fashion and zeitgeist. It is difficult to tell the ideal weight for a specific individual. Nevertheless, it is possible to determine which body weight at which height corresponds to the statistical average, promotes a long life expectancy, and improves your health.
Obesity is defined as an excessive high body weight in relation to body size. This ratio is calculated using the so called "body mass index" (BMI). The BMI results from the body weight in kilograms [kg] divided by the square of the height in meters [m2]. The recommended BMI depends on age and is summarized in the following table.
Being overweight is a risk factor for many diseases. It leads to high blood pressure, burdens the bones and joints and increases the risk of diabetes. For an overweight individual the relative risk of suffering a stroke is around one to two times higher than the risk for a person of normal weight.
Therefore: Get moving! This is one of the most important measures to reduce obesity. Basically, endurance sports are helpful. Start slowly, but: Get Started!
Diabetes is a major risk factor for stroke. Diabetes is a collective term for many different forms of metabolic disorders which have in common that the blood sugar level is too high after eating and after fasting. In patients with diabetes the blood vessel walls are affected. They thicken and thus hinder the blood flow. The thickening of vessel walls is mediated among other things by atherosclerosis and is exacerbated by all forms of diabetes including, for example, "adult onset diabetes".
The risk of stroke is two to three times higher in people with diabetes than in healthy people. Initially, many people with diabetes do not realize that they have the disease. Diabetes does not hurt, so the disease is often noticed late. The most common form is adult onset diabetes.
A disease can only be treated if it is detected. Regular check-ups testing for diabetes are therefore useful.
Cardiac Arrhythmias (Atrial Fibrillation)
Cardiac arrhythmias are perturbations in the normal cycle of the heartbeat, more specifically in the heart muscle excitation. The heart beat is no longer regular. One particular type of heart rhythm disorder, atrial fibrillation, entails a significant increase in the risk of stroke: It is at least five times higher. About 5 % of all people with atrial fibrillation have a stroke each year. If the patient suffers from other diseases such as coronary heart disease or cardiac insufficiency additionally, the risk increases by a factor of two to three. The presence of rheumatic heart disease is particularly serious. In atrial fibrillation with rheumatic heart damage, the risk increases seventeen-fold. The data from scientific studies also suggests that especially elderly people with atrial fibrillation are at increased risk of stroke.
Atrial fibrillation is common: 2—3 % of people between 40 and 65 years suffer from atrial fibrillation and about 5% of those aged over 65 years.
By feeling your pulse at the wrist you can easily determine whether or not the heartbeat is regular. Many species of cardiac arrhythmias can be detected with EKG. Again, many people do not know that they have cardiac arrhythmias. Only an examination can bring certainty.
In the prevention of stroke with atrial fibrillation, drugs are used to thin the blood and prevent the formation of blood clots. These so called oral anticoagulants can be very effective in preventing stroke or systemic embolism.
Prevention is the best and safest stroke protection. Living a healthy life can reduce or completely exclude some of the risk factors in advance. A healthy lifestyle includes:
- a sensible diet with a high proportion of fruits, vegetables, low-fat and low-sugar food
- regular exercise and sports
- an adequate fluid intake – especially elderly people need to be careful because the "sensation of thirst" decreases with age
- no smoking
- avoiding stress
- losing weight
If – despite a healthy lifestyle – some risk factors persist, please have regular medical check-ups.