Stroke

Brain cells need a constant supply of oxygen and nutrients. They are delivered by a network of blood vessels that reach every part of the brain. When something cuts off that supply, brain cells downstream begin to die. The injury that follows is called a stroke.

Most strokes strike when a blood clot becomes lodged in one of the brain's arteries, blocking blood flow. In some cases, the clot forms inside the artery, usually because a cholesterol-filled plaque inside the artery breaks open. This is called a thrombotic stroke. In other cases, a blood clot or a solid mass of debris that originates elsewhere travels to the brain, where it blocks a brain artery. This is called an embolic stroke. A third type of stroke, hemorrhagic stroke, occurs when a blood vessel in the brain bursts.

Since different areas of the brain are responsible for different functions, symptoms of stroke vary. They can be changes in sensation, movement, sight, speech, balance, and coordination. Sometimes a stroke is preceded by one or more transient ischemic attacks (TIAs). These are brief episodes of stroke-like symptoms that last for a few minutes — or possibly up to 24 hours — but that go away on their own.

If you think that you, or someone you are with, is having a stroke, call 911 right away. The sooner you call, the sooner treatment can begin — "time is brain," as emergency room doctors say. The type of treatment depends on the type of stroke that has occurred. If the brain's blood supply is restored quickly and completely, a full recovery with little or no disability is possible. The more widespread the damage, and the greater delay of treatment, the more severe and long-lasting the damage.

Recovery after a stroke depends on how well healthy areas of the brain take over duties that had been performed by the damaged brain tissue. To some extent, especially in children and young adults, recovery is possible because of the brain's ability to compensate for damage in one area by working harder in another — by relying on alternate wiring for some functions or by rewiring around the injured site. When such rewiring isn't possible, rehabilitation techniques can help the brain recover function.

Stroke Articles

Transfusion and heart surgery: Only when needed

The practice of routinely giving blood transfusions to patients during and after heart surgery is being challenged by research findings. In an eye-opening British study published in 2007, people who received a transfusion during or after heart surgery were six times more likely to have developed a complication related to ischemia (insufficient oxygen delivery to the tissues), such as heart attack, stroke, kidney trouble, and even death, when compared with those who did not get a transfusion.  (Locked) More »

Recognizing stroke early

Early treatment of the most common type of stroke, ischemic stroke, can limit brain damage and vastly improve outcomes. Ischemic stroke is the kind caused by atherosclerosis, which causes blood clots that block the blood supply to a part of the brain. Yet too few ischemic stroke patients receive important clot-busting drugs, which are most effective when given within three hours after symptoms start. Patients often arrive at the hospital after that window of opportunity has closed. They delay getting treatment because stroke symptoms may not be that pronounced or they are mistaken as coming from other, less serious problems. As a result, doctors are looking for ways to make it easier for the layperson to identify a stroke. The Cincinnati Prehospital Stroke Scale is one such attempt. Some experts say it leaves out too many symptoms. Others say it will cause false alarms because it's not specific enough.. Even so, the Cincinnati scale is a beginning. In one study, if any of the three tests that are part of the scale were abnormal, the chances that the person had suffered a stroke were about 70%. More »

“Mini-strokes” have major risks

What's the difference between a stroke and a transient ischemic attack (TIA)? At first, not much. They look the same, feel the same, and stem from the same thing — blocked blood flow to the brain. But a stroke lasts for hours, maybe longer, while a TIA fades away after a few minutes. Don't be fooled by the disappearance of symptoms. Even after they are gone, danger still lurks in the form of other TIAs, stroke, and even death. A study published in the April 2005 Stroke looked at all the people who had a TIA in the Cincinnati area during a single year. In the three months following the mini-stroke, 1 in 7 people (14.6%) had a full stroke, and 1 in 4 (25.2%) had either died or suffered a stroke or another TIA. More »