What is a stroke?

A stroke is damage to part of the brain when its blood supply is suddenly reduced or stopped. The part of the brain deprived of blood dies and can no longer function.

How does it occur?

Blood is prevented from reaching brain tissue when a blood vessel becomes blocked or bursts inside the brain. There are several types of strokes:

• A thrombotic stroke occurs when a blood clot (thrombus) forms in an artery and blocks blood flow to the brain.

• An embolic stroke occurs when a blood clot or a piece of debris called plaque, which formed in another vessel in the body, breaks away and flows through the bloodstream to the brain. The clot or clump of plaque then blocks an artery in the brain.

• A lacunar stroke is caused by a blockage in certain small blood vessels inside the brain.

• A cerebral hemorrhage occurs when an artery in the brain tears or bursts, causing blood to spill out. A hemorrhage often happens without warning. It usually occurs as a result of high blood pressure. Less often it may result from a blood vessel defect present since birth.

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

• high blood pressure

• heart disease

• diabetes

• high cholesterol level

• cigarette smoking

• family history of stroke

• overweight

• hardening of the arteries (atherosclerosis, or fatty cholesterol deposits on artery walls).

What are the symptoms?

The symptoms of a stroke differ, depending on the part of the brain affected and the extent of the damage. Symptoms following a stroke may include:

• severe headache

• weakness, numbness, or tingling in the face, arm, and leg on one side of the body

• inability to walk

• inability to speak or difficulty speaking

• difficulty understanding when spoken to

• vision problems

• confusion or personality changes

• difficulty with muscle movements, such as swallowing, moving arms and legs

• dizziness

• loss of bowel and bladder control

• problems with judgment

• loss of consciousness.

Warnings known as transient ischemic attacks (TIAs) may happen before the actual stroke. TIAs occur when the blood supply to the brain is cut off for a short time without causing permanent damage. A TIA is sometimes referred to as a ministroke because it causes the same symptoms as a stroke but the symptoms go away within minutes to a few hours.

Let your doctor know immediately if you have any of these symptoms.

How is it diagnosed?

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

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

The following tests will be done:

• lab tests of your blood

• electrocardiogram (ECG) to look at how your heart is working

• x-ray of your chest

• brain scans (CT or MRI) to try to identify a stroke and determine whether it is from a clot or from bleeding into the brain from a leaking artery (hemorrhage).

How is it treated?

It is important to get to the hospital as soon as possible if you suspect a stroke. Many large hospitals are now treating strokes caused by blood clots with clot-dissolving medicines. These medicines can cause the symptoms to stop very quickly. They can prevent long-term disability or death. This treatment works only if the medicines are given within the first 3 to 6 hours after the stroke began.

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.

Depending on the severity of your symptoms and how soon you are alert and able to start exercises, in the bed or out of the bed, you will begin your rehabilitation (rehab) program. Most stroke rehab programs last several weeks to several months after you leave the hospital. The program consists of physical therapy, occupational therapy and, if needed, speech therapy.

• Physical therapy helps you regain muscle strength and 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 the extent of the brain injury. Some improvement may occur rapidly 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 doctor can tell you more accurately what further recovery you can expect.

How can I take care of myself?

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

How can I prevent a stroke from occurring?

• If you have high blood pressure, it is essential that you control it with medication.

• If you smoke, quit.

• Keeping your diet low in fat will decrease the risk of developing fatty deposits in your blood vessels.

• Exercise every day according to your doctor's recommendations.

• Keep a healthy weight.