The following signs may indicate a stroke or the onset of a stroke. They may last a few minutes or a few hours. If you experience them, or notice them in another person, you should seek emergency medical help immediately.
Stroke (medically termed cerebrovascular accident or CVA) is a major cause of disability worldwide. It is mainly a disease of older age with 85 per cent occurring in people over age 65. Twenty per cent of people with a stroke die within a month. Of those who survive, 90 per cent have permanent disabilities and 30 per cent are severely limited by these disabilities. Strokes can have a devastating impact on quality of life. Many patients need to be cared for in nursing homes rather than living at home.
The good news is that prevention and early treatment over the past 30 years have helped reduce the suffering caused by strokes. One major reason for the decrease is likely due to better blood pressure control. There is still a lot of work to be done, however, before this deadly disease is eliminated.
A stroke is a loss of function due to sudden damage to the brain. The cause is either ischemic, a blocked blood vessel preventing blood flow to a part of the brain (85 per cent), or hemmoragic, the bleeding into the brain tissue from a broken blood vessel (15 per cent). The symptoms of a stroke vary, depending on which part of the brain has been damaged and how large that area of damage is.
Anyone who has already had a stroke is at increased risk of another. Another group at risk are those who have had a T.I.A. (transient ischemic attack). This is a temporary loss of function usually lasting less than two hours and certainly no longer than one day. Common symptoms are blindness in one eye, speech problems, double vision, dizziness or one-sided weakness or numbness.
Besides older age, many medical conditions increase the chance of having a stroke. Major risk factors include high blood pressure, smoking, high cholesterol, diabetes, heart disease, including heart rhythm disturbances, and narrowed arteries in the neck. Less important factors include obesity and heavy alcohol use. Treatment of these conditions can lower the risk of stroke.
A person with high blood pressure has four times greater risk of stroke than someone with normal blood pressure. For all age groups, lowering the blood pressure is useful in reducing the chance of stroke. It also helps to reduce heart attacks.
Smoking increases stroke risk by two-to fourfold. Within two to five years after stopping smoking, stroke risk falls, though not back to the rate of a never-smoker. Stopping smoking is extremely important in reducing chance of stroke but a better protection is not to start at all.
Treatment of high cholesterol levels through a low-fat, low-cholesterol diet, exercise and lipid-lowering medication reduces the risk of stroke by one-third.
One-third of patients with a heart attack develop a clot along one wall of the heart. Without treatment, 15 per cent of these patients go on to have a stroke within the next two years. Now, after heart attack, those at high risk are placed on blood thinners (Warfarin™) to prevent clot formation and reduce stroke risk.
Atrial fibrillation (AF) is a rhythm disturbance of the heart. Clots can form as a result. People in whom AF occurs are at five to six times higher risk of having a stroke. The increased risk becomes greater as a person becomes older. The greatest risk will be found in those over 75 years of age, or with a previous stroke or high blood pressure, diabetes or heart disease. For these, the yearly risk of stroke is four per cent, as in four out of 100 people with AF will have a stroke each year.
Blood thinners are used to reduce the risk of clot formation and reduce the chance of stroke by nearly 70 per cent. Narrowed carotid arteries in the neck at least double the stroke risk and are frequently a cause of T.I.A. The narrower the artery, the greater the risk. If a person is otherwise healthy, surgery can be done to improve blood flow (carotid endarterectomy). This in turn lowers the risk of stroke.
Diabetes triples stroke risk but unfortunately good control of blood sugar has not proved to lower risk. Prevention of obesity by diet and exercise may reduce Type II diabetes that develops in middle and older age. Preventing diabetes can reduce stroke incidence overall.
After a stroke, an anti-platelet medication (blood thinner) may be prescribed depending on the patient’s individual circumstances to reduce the risk of another stroke.
If your arteries are less than 50 per cent narrowed, taking an anti-platelet medication such as ASA (Aspirin™) every day will reduce the chance of having a stroke. Your family doctor can advise you about the best way for you to use ASA.
High blood pressure, high cholesterol levels and narrowing of the carotid arteries are frequently present without any obvious symptoms. Regular check-ups by a nurse practitioner or family doctor are useful in detecting these problems early so that effective treatment can be started.
If someone in your family has had a stroke, you may have a risk factor and you should have regular check-ups to promote early detection. Stopping smoking, moderating alcohol consumption and managing weight are other lifestyle changes that you can choose to further lower your risk of this debilitating disease.