Blood vessels that carry blood to the brain from the heart are called arteries. The brain needs a constant supply of blood, which carries the oxygen and nutrients it needs to function. Specific arteries supply blood to specific areas of the brain. A stroke occurs when one of these arteries to the brain is either blocked or bursts. As a result, part of the brain does not get the blood it needs, so it starts to die.
A stroke is a brain attack. It is caused by an interruption of the blood supply to part of your brain. Because your brain controls everything your body does, a stroke will affect the way your body functions. For example, if a stroke damages the part of your brain that controls your right leg, then you may have weakness or numbness in that leg. Your brain also controls how you think, learn, feel and communicate. A stroke is sudden and the effects on your body are immediate.
CVA – this stands for cerebrovascular accident (the medical name for a stroke). It is better to say ‘stroke’ as strokes are not accidents – there is always a cause.
Infarction – this means an area of brain tissue hasn’t received its blood supply and as a result it has been damaged.
A Transient Ischemic Attack (TIA) is caused, in the same way as an ischemic stroke, by the presence of a blood clot that temporarily obstructs the cerebral blood flow. In the case of a TIA, the symptoms usually last less than an hour and no brain injury is visible upon the radiological examinations.
Are you at risk?
Anyone, including children, can have a stroke. Every year, about 610,000 people in the United States have a new stroke. Several factors that are beyond your control can increase your risk for stroke. These include your age, sex, and ethnicity. But there are many unhealthy habits that you can change. Examples include smoking, drinking too much alcohol, and not getting enough exercise.
What are the common signs of a stroke?
• Numbness, weakness, or paralysis on one side of the body.
• Slurred speech, difficulty thinking of words or understanding other people.
• Sudden blurred vision or sight loss.
• Being unsteady on your feet.
• Severe headache.
• Over 80 percent of strokes are caused by a blockage in an artery supplying blood to the brain. This is known as an ischaemic stroke. There are three main types of ischaemic stroke:
1. A blood clot that forms in a main artery to your brain.
2. A partial clot that may form in your heart or the blood vessels of your neck. This partial clot can be carried in your bloodstream to your brain and get lodged in an artery. This is a cerebral embolism.
3. A blockage that occurs in the tiny blood vessels deep in your brain. This is a lacunar stroke.
• Up to 20 percent of strokes are caused by a bleed into your brain from a burst blood vessel. This is called a cerebral haemorrhage.
• A transient ischaemic attack (TIA) or mini-stroke is a sudden and brief disturbance of your brain caused by small clots. Stroke symptoms from a TIA last less than 24 hours before going away. TIAs do not cause any long term damage.
However, they are a serious warning sign that you may have a full stroke in the near future. Approximately 10 percent of people with a TIA will have a stroke within a week and 20 percent of people will have a stroke within a month. TIAs should not be ignored and urgent medical attention is required.
How to diagnose a stroke or a TIA?
In the Emergency Care Unit, the neurologist, the brain specialist, prescribes several examinations to determine the cause of the cerebral attack and to locate the affected area.
CT-Scanner: this examination, a kind of an X-ray of the brain, confirms if you have had a stroke. It indicates the type of stroke you have suffered: an ischemic stroke caused by a blood clot or a hemorrhagic stroke (cerebral hemorrhage) caused by bleeding.
MRI (Magnetic Resonance Imaging): this uses a magnetic field system to create cross-sectional images. This enables «abnormal» tissues to be differentiated. The MRI also detects small lesions and helps to refine the diagnosis.
Doppler Ultrasound: the ultrasound examination is used to measure blood flow speed which shows if an artery has narrowed. The arteries in the neck and those inside the brain are visualized.
Echocardiography: this examination performed using ultrasound shows the contours and the inside of the heart. A probe (a sensor) is moved across the surface of the chest, and the image is displayed on the computer.
The holter or the R-Test: this examination is performed to record the activity of your heart for a total period of 24 hours (or 7 days for the R-Test) to detect cardiac rhythm disorders. A small box connected to electrodes is placed on your chest for 24 hours and you write on a sheet your activities (walking, meals, sleep, etc.) and when you feel palpitations.
Neuropsychological examination: a neuropsychologist or a speech therapist will assess your language, your understanding and your memory abilities in particular through tests (drawings, writing). These tests last an average of two hours and are repeated if needed.
If you have high blood pressure, lower it. Measurement of 130/80 mm Hg and above is considered high blood pressure, work with your health care provider to manage it.
Find out if you have atrial fibrillation (AFib). AFib is a quivering or irregular heartbeat that can lead to blood clots and cause a stroke. Your health care provider can tell you if you have AFib and help you manage it.
If you smoke, stop. Smoking doubles the risk for stroke.
If you drink alcohol, do so in moderation. Heavy drinking can increase your risk for stroke.
Lower your cholesterol (the fat-like substance in your blood). Studies suggest ideal total cholesterol levels at about 150 mg/dL, which equals about 100 mg/dL for low-density lipoprotein cholesterol (LDL-C). Lower cholesterol levels are linked with lower rates of heart disease and stroke.
If you have diabetes, follow your health care provider’s advice carefully to get your blood sugar level under control. Having diabetes puts you at an increased risk for stroke. Talk to your health care provider about a diet that will help you manage your diabetes, such as limiting foods high in added sugars.
Exercise daily. Even a little exercise—a brisk walk, swim or yard work—can improve your health and may reduce your stroke risk. Check with your health care provider before starting a new exercise regimen.
Cut down on sodium and saturated and trans fat. By reducing these, you can lower your risk for stroke, high blood pressure and heart disease.
The vital functions (oxygen, blood pressure, body temperature) and neurological functions (check for language ability, strength, sensitivity) are monitored immediately. Your treatment is then adapted to your specific situation and the cause of the stroke.
Thrombolysis consists in injecting a powerful drug into a vein in order to dissolve the clot which is clogging one of your vessels. This treatment is only possible within the first 4.5 hours after the onset symptoms and depending on your condition.
Thrombectomy is the extraction of the blood clot clogging a vessel inside the brain. This procedure requires the introduction of a catheter in the groin area, which is then guided up to the clogged artery. The clot is then extracted using a stent (a small cylinder often used to unblock the coronary arteries) that holds it in its mesh. The stent is then removed.
Drugs or medical treatment such as platelet inhibitors which prevent the formation of blood clots (aspirin for example) or anticoagulants are also administered as the case may be.
The physiotherapist focuses on your mobility and comfort: positioning, respiratory therapy, learning how to move, body positioning, learning how to walk again.
Do people recover after a stroke?
The brain needs time to heal and recovery can take many months. Recovery is different for each person. Some people may recover and have only a slight disability. Other people may have more serious disabilities. In general, most recovery is made in the first year, but you can still make progress after this time. Unfortunately, some people will not recover from a stroke. People who are dying as a result of a stroke should be given end-of-life care.