Stroke (Cerebrovascular Accident)

What is a stroke?

A stroke is damage to the brain when the blood supply to part of the brain is suddenly reduced or stopped.

A stroke may also be called a cerebral vascular accident, or CVA.

How does it occur?

A stroke may be caused by anything that blocks stops the blood supply to a part of the brain. Blood can be prevented from reaching brain tissue when a blood vessel leading to the brain becomes blocked (ischemic) or bursts (hemorrhagic).

• An ischemic stroke is the most common kind of stroke. It may occur when there is a blockage in a blood vessel in the brain.
  • An artery in or leading to the brain may become severely narrowed, usually from atherosclerosis. Atherosclerosis is a condition in which fatty deposits build up in the blood vessels, creating thickened areas called plaque. The plaque and the narrowing of the blood vessels can block the flow of blood. A small piece of plaque may break off from the wall of a blood vessel and completely block a smaller blood vessel downstream.
  • The blockage may be caused by a blood clot that forms in a blood vessel of the brain or neck. This type of blockage is called a thrombus.
  • The blockage may be caused by a clot or other material that travels from another part of the body to the brain or neck. This type of clot is called an embolism.
• A hemorrhagic stroke happens when an artery in the brain breaks and bleeds into the brain. A hemorrhage often happens without warning. It usually occurs as a result of high blood pressure. Sometimes it results from a blood vessel defect you have had since birth.

Your risk of stroke is increased if:

• You are over the age of 55.
• You have a family history of stroke.
• You are African American.
• You are male.
• You have already had a stroke or you have had a TIA (transient ischemic attack) or heart attack.

Any of the following factors can also increase the risk of a stroke:

• high blood pressure
• cigarette smoking
• diabetes
• high cholesterol level
• carotid or other artery disease
• heart rhythm problems such as atrial fibrillation
• other heart disease, such as heart failure or heart valve disease
• sickle cell anemia
• unhealthy diet
• being overweight
• too little physical activity
• alcohol or drug abuse.

Research has identified metabolic syndrome as doubling the risk of stroke. It also increases the risk of heart disease and diabetes. Metabolic syndrome, also known as syndrome X, is defined as the presence of 3 or more of the following health conditions:

• excess weight around the waist (waist measurement of more than 40 inches for men and more than 35 inches for women)
• triglycerides blood level of 150 mg/dL or more
• HDL cholesterol levels below 40 mg/dL for men and below 50 mg/dL for women
• blood pressure of 130/85 mm HG or higher
• prediabetes (a fasting blood sugar between 100 and 125 mg/dL, or between 5.6 and 6.9 mmol/L) or diabetes (a fasting blood sugar level over 125 mg/dL, or over 6.9 mmol/L).

What are the symptoms?

The symptoms of a stroke differ, depending on what part of the brain is affected and how much it is damaged. Symptoms following a stroke come on suddenly and may include:

• weakness, numbness, or tingling in the face, arm, or leg, especially on one side of the body
• trouble walking, dizziness, loss of balance, or coordination
• inability to speak or trouble speaking or understanding what others are saying
• trouble seeing with one or both eyes, or double vision
• confusion or personality changes
• trouble with muscle movements, such as swallowing or moving arms or legs
• loss of bowel and bladder control
• severe headache with no known cause
• loss of consciousness.

Warnings known as transient ischemic attacks (TIAs) may happen before a stroke. TIAs happen when the blood supply to the brain is reduced for a short time without causing lasting damage. The symptoms of a TIA are similar to the symptoms of a stroke. A TIA is not a stroke but it can mean that you are at high risk of having a stroke.

Call 911 if you see or have any of the symptoms of a stroke. Treatment can be more effective if given quickly. Every minute counts.

How is it diagnosed?

If you have symptoms of a stroke, someone should call an ambulance or take you to an emergency room right away.

Your healthcare provider will know from your symptoms and physical exam whether you are having a stroke.

The following tests may be done:

• MRI (magnetic resonance imaging), which uses magnetism, radio waves, and a computer to make pictures of the brain and blood vessels in the brain and neck
• CT scan, which uses computerized X-rays to make pictures that can show plugged blood vessels in the brain or neck
• ultrasound scans to show blood flow in blood vessels of the head and neck
• cerebral arteriogram to look at the blood vessels in the brain
• electrocardiogram (ECG), which is a recording of the electrical activity of your heart
• echocardiogram, which is an ultrasound scan of the heart
• blood tests.

How is it treated?

It is important to get to the hospital as soon as possible if you suspect a stroke. Strokes caused by blood clots can be treated with clot-dissolving medicines. These medicines can cause the symptoms to stop very quickly. They can prevent long-term disability or death. This treatment needs to be given within the first 3 to 4.5 hours after you start having symptoms.

All strokes require careful observation, especially in the first 24 hours. In addition to bed rest, you will probably need an IV and oxygen. Underlying medical problems that may have caused the stroke, such as high blood pressure or heart rhythm problems, will be treated. Surgery may be needed to repair a blood vessel or remove a blood clot.

Rehabilitation may start at the hospital or at a nursing facility. Most stroke rehab programs last several weeks to several months after you leave the hospital. The program includes physical therapy, occupational therapy, and if needed, speech therapy.

• Physical therapy can help you get your muscle strength back. It teaches you ways to move safely with weak or paralyzed muscles.
• Occupational therapy helps you relearn ways of eating, dressing, and grooming.
• Speech therapy may help you if you have problems with swallowing, speaking, or understanding words.

How long will the effects last?

Recovery depends on how much the brain was damaged. There may be some quick improvement within the first few days and weeks after the stroke. Other improvement may occur more gradually. If recovery does not begin within 1 to 2 weeks of the stroke, some muscle movement and speech may not return. However, some people continue to regain speech and muscle strength up to 1 year after a stroke. By the end of the rehab program, your healthcare provider can tell you more accurately what further recovery you can expect.

How can I take care of myself?

Discuss with your healthcare provider the cause of your stroke, and follow his or her advice on how to avoid another one. Your provider may advise diet changes, regular exercise, and programs for stress management.

Ask your provider if you should take aspirin. If your stroke was hemorrhagic (caused by bleeding) you will probably not take aspirin. If you had an ischemic stroke (caused by blockage of a blood vessel) and you were taking aspirin before you had the stroke, your provider may prescribe a higher dose or switch to a different medicine to prevent clots, such as clopidogrel.

How can I prevent a stroke from occurring?

• If you have high blood pressure, you need to control it. Most often, this means taking medicine for your high blood pressure.
• If you have diabetes, keep good control of your blood sugar.
• If you have a type of irregular heart rhythm called atrial fibrillation, your provider may prescribe the medicine warfarin to help prevent clots.
• If you smoke, quit.
• Keep your diet low in fat to decrease the risk of developing fatty deposits in your blood vessels.
• Exercise every day according to your healthcare provider's recommendations.
• Keep a healthy weight.

Disclaimer: This content is reviewed periodically and is subject to change as new health information becomes available. The information provided is intended to be informative and educational and is not a replacement for professional medical evaluation, advice, diagnosis or treatment by a healthcare professional.

HIA File neur3430.htm Release 13/2010