HealthyCanada.com

Overview

A stroke is a sudden loss of brain function that is caused by the interruption of the flow of blood to the brain (an ischemic stroke) or the rupture of blood vessels in the brain (a hemorrhagic stroke).

Every year more than 50000 Canadians suffer a stroke and about 16000 people die as a result. The good news is that over the past three decades the number of deaths has dropped by about 60%. Stroke is however still the leading cause of disability in this country.

While a stroke can strike at any age it is more common in older adults. The risk doubles every decade for those over the age of 55.

Cause

There are three different types of stroke:

The most common type of stroke (about 80%) is ischemic. An ischemic stroke is caused when a blood clot forms in one of the arteries that supplies blood to the brain. This cuts off the supply of oxygen and nutrients to the brain which causes cells (neurons) in the affected area to die.

A hemorrhagic stroke is caused when a blood vessel leaks and pours blood into the brain. This can happen as a result of high blood pressure or aneurysms (weak spots in the walls of the blood vessels).

A transient ischemic attack (TIA) or a "mini-stroke" is caused when blood flow to certain areas of the brain is temporarily restricted. This can last for just a few seconds and often goes unnoticed because plenty of healthy cells are left undamaged to carry out the normal functions of the brain. TIAs are thought to be an early warning sign of a stroke.

These three types of stroke carry different consequences but all are extremely serious and require immediate medical attention.

There are more than a dozen factors that increase your risk of having a stroke:

Family history

You will have a slightly higher risk of stroke if one of your parents or a brother or sister has had a stroke or mini-stroke.

Age

Your risk of having a stroke increases as you get older doubling every decade after the age of 55.

Gender

Men and women are affected by stroke equally. However women are more likely to die as a result.

Race

Blacks are at greater risk of stroke than are people of other races. This is partly due to a higher prevalence of high blood pressure and diabetes.

Previous stroke or TIA

If you've already had a stroke your risk of having another one increases. In addition people who have had a TIA are nine times as likely to have a stroke as are those who haven't.

High blood pressure

High blood pressure can weaken and damage blood vessels in and around your brain leaving them vulnerable to atherosclerosis and hemorrhage.

High blood cholesterol

High levels of "bad" cholesterol and triglycerides may increase your risk of atherosclerosis. In contrast high levels of "good" cholesterol reduce your risk of atherosclerosis by helping cholesterol exit your body through the liver.

Smoking

Smoking contributes to plaques in your arteries. Nicotine forces your heart to work harder by increasing your heart rate and blood pressure. The carbon monoxide in cigarette smoke replaces oxygen in your blood which lowers the amount delivered to the walls of your arteries and the tissues in your brain.

Diabetes

People with diabetes can't process sugar and fat properly which contributes to atherosclerosis. They also tend to have high blood pressure. Diabetes also interferes with the body's ability to break down blood clots.

Obesity

Being overweight increases your chance of developing high blood pressure heart disease atherosclerosis and diabetes · all of which increase stroke risk.

Cardiovascular disease

Atrial fibrillation is the most common condition associated with strokes caused by embolic clots. In addition atherosclerosis in blood vessels near your heart may indicate that you have atherosclerosis in other blood vessels · including those in and around your brain.

Use of birth control pills

The risk of stroke is higher among women who take birth control pills especially among smokers and women older than 35.

Uncontrolled stress as well as binge drinking or the use of cocaine and other illicit drugs can also increase your risk of stroke.

Symptoms

Tell someone and call 9-1-1 immediately if you experience any of these five main warning signs of a stroke:

• Sudden weakness numbness or tingling in the face arm or leg
• Sudden temporary loss of speech or trouble understanding speech
• Sudden loss of vision particularly in one eye or double vision
• Sudden severe and unusual headache
• Sudden loss of balance especially with any of the above signs

Researchers are optimistic that new and developing treatments for stroke will reduce brain damage resulting from stroke. However treatment is only effective when used within three to six hours of a stroke beginning. That's why it's important to recognize the warning signs and get medical attention immediately. The longer a stroke goes untreated the greater the damage and potential disability.

A stroke can affect your:

• Ability to feel touch temperature pain and movement
• Ability to see or to interpret what you see
• Ability to think to remember understand plan reason or problem-solve
• Ability to communicate (speaking and understanding speech as well as reading writing and the ability to do mathematics)
• Personality
• Emotions
• Behaviour

Getting prompt medical treatment for stroke is important. Treatment will depend on where the brain was injured as well as how much damage occurred.

Ischemic stroke

The first priority in treating an ischemic stroke is the removal of any blockage to restore normal blood flow to the brain. If you get to the hospital quickly doctors can administer a clot-busting drug into your veins. There is a very narrow window of opportunity for this treatment as the drug has to be given intravenously within three hours to improve your chances of survival and reduce the amount of disability you may suffer.

Surgery to open up a narrowed artery and remove plaque is another option as is an angioplasty a procedure in which a balloon-tipped catherter is inserted into the obstructed artery. When the balloon is inflated plaque is compressed against the artery walls clearing the way for renewed blood flow.

Hemorrhagic stroke

Surgery may be used to treat a hemorrhagic stroke or prevent another one.

With proper care about 25% of stroke sufferers will recover completely. But the success of most treatments depends on how soon a person is seen by a doctor in a hospital emergency room after signs and symptoms begin.

After you recover your doctor will want to ensure that you are not smoking and that your blood pressure is under control. He may also recommend that you take a daily low-dose aspirin which will help lessen the risk of another stroke by up to 30%. (A stroke survivor has a 20% chance of having another stroke within 2 years.) Anticoagulants are also an option in some cases.

Because a stroke can leave you disabled you will likely need the help of physiotherapists speech and occupational therapists. Rehabilitation can be a long and frustrating process as other parts of the brain and body learn to take over from areas that no longer function. There could be speech and language problems or you might have difficulty breathing or swallowing. Your balance and hearing could be off. Sight can be affected. As well some people have little or no control over their bladder or bowel. Depression is also common among those who've suffered a stroke. The good news is that with early treatment and lots of encouragement and support it is possible for those who've had a stroke to become independent and productive again.

You can help prevent a stroke by making appropriate lifestyle changes that include not smoking drinking only moderate amounts of alcohol exercising regularly maintaining an appropriate weight and having your blood pressure and cholesterol checked. Ask your doctor if you should be taking a daily low-dose aspirin or another drug that can help reduce blood clots.

Research has also shown that certain foods may help protect against stroke. These include:

• Five or more daily servings of fruits and vegetables which contain nutrients such as potassium folate and antioxidants.
• Foods such as oatmeal and beans which are rich in soluble fibre.
• Foods rich in calcium.
• Soy products which can reduce your "bad" cholesterol and raise your "good" cholesterol level.
• Foods rich in omega-3 fatty acids including cold-water fish such as salmon mackerel and tuna.