Identifying a Stroke

This past weekend, Americans saw the effects a stroke can have on a person as they watch Dick Clark anchor his yearly telecasts. And now, Ariel Sharon is in a Israeli hospital after suffering a major stroke. But just what is a stroke? How can you spot it? Can you reduce the damage if you know you're having one? And most importantly, can they be prevented? For these answers, and more, TDI turns to WebMD to learn more.

What is a stroke? A stroke occurs when a blood vessel (artery) that supplies blood to the brain bursts, or when the vessel or artery is blocked by a blood clot. Within minutes, the nerve cells in that area of the brain are damaged, and they may die within a few hours. As a result, the part of the body controlled by the damaged section of the brain cannot function properly.

Are there more than one kind of stroke? Yes. There's a Ischemic stroke, which is a blocked blood vessel. About 80% of all strokes are ischemic. Then there's a Hemorrhagic stroke, which occurs when an artery in the brain leaks or ruptures.

What causes a Ischemic stroke? Blood clots usually result from other problems in the body that affect the normal flow of blood, such as the hardening of the arteries (atherosclerosis), which is caused by high blood pressure, diabetes, and high cholesterol. It's also caused by atrial fibrillation (or other irregular heart rhythms), heart valve infections or other problems, inflammation of the blood vessels, blood-clotting disorders, or a heart attack.

What causes a Hemorrhagic stroke? Bleeding in the space around the brain are most often caused by a ruptured aneurysm, or by uncontrolled high blood pressure. Other less-common causes include inflammation in the blood vessels, blood-clotting disorders, head or neck injuries that result in damage to blood vessels, radiation treatment for cancer in the neck or brain, or a degenerative blood vessel disorder, known as Cerebral amyloid angiopathy.

How do I know that a loved one, or myself, is having a stroke? General symptoms of a stroke include numbness, weakness, or paralysis of the face, arm, or leg, typically on one side of the body. Symptoms also include vision problems in one or both eyes, such as dimness, blurring, double vision or loss of vision. Also, confusion, slurred speak, comprehension issues, trouble walking, dizziness, loss of balance or coordination, or a severe headache. A stroke may progress over hours or days, usually in a stepwise fashion.

For an ischemic stroke, symptoms may be so minor that they are either ignored, or they go unnoticed. Some ischemic strokes are proceeded by transient ischemic attacks (TIAs), which have symptoms similar to a stroke, except the loss of vision is described as the feeling that a "shade is being pulled down over your eyes." These symptoms are also temporary and improve, usually within 10 to 20 minutes. Symptoms of an ischemic stroke usually occur on one side of the body.

Symptoms of a hemorrhagic stroke can be similar to their ischemic cousin, but may be distinguished by symptoms relating to higher pressure in the brain, including severe headache, nausea and vomiting, neck stiffness, dizziness, seizures, irritability, confusion, and possibly unconsciousness. Hemorrhagic strokes also usually occur during the daytime and during physical activity. Symptons usually begin very suddenly and evolve over several hours.

What happens during a stroke? With an ischemic stroke, the oxygen-rich blood supply to part of your brain is reduced. With a hemorrhagic stroke, there is bleeding in the brain. After about 4 minutes without blood and oxygen, brain cells in the affected part of the brain become damaged, and without immediate treatment, may die. The body tries to restore blood and oxygen to the cells by enlarging other arteries near the area. If the clot is in a large blood vessel, the body may not be able to enlarge other arteries through other vessels. Permanent brain damage usually occurs when blood supply is not restored.

When should I call a doctor or 911? Whenever symptoms of a stroke occur. The sooner you get treated, the better the chances are for recovery.

What increases my risk for stroke? It's important to note that you can only control the risk factor for a stroke, you can't really prevent one. Your chances for a stroke are high if you're old, or if you have high blood pressure. Another huge risk factor is diabetes. High cholesterol, coronary artery disease, heart valve conditions, smoking, being overweight, not being active, heavy use of alcohol (especially binge drinkers), using cocaine or other such substances.

Is there anything else I can do? If you think that you are having a symptom of a stroke, it may just be one of those transient ischemic attacks (TIA), a warning sign that a stroke may soon occur. Getting medical help right away may help prevent a stroke. You can further educate yourself on strokes by reading the full WebMD entry on strokes here, or by visiting the National Stroke Association for more information.