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

Chiropractic neck adjustments linked to stroke

Quick, thrusting movements done to ease neck pain—known as cervical manipulative therapy—have been linked to tears in the arteries of the neck. People at risk of cardiovascular disease should be extra cautious about getting this treatment. (Locked) More »

Treating narrowed arteries in the neck

The buildup of plaque deposits in the carotid arteries of the neck can block blood flow to the brain and cause a stroke. The arteries can be unclogged either with an operation called carotid endarterectomy or angioplasty plus placement of a stent. Both procedures are safe and effective when performed on a good candidate by an experienced doctor. For people who can’t have surgery, drug treatment is a good option for preventing stroke. (Locked) More »

Uncovering a hidden cause of stroke

Unrecognized atrial fibrillation may be to blame for up to 40% of unexplained strokes. Subsequent brain attacks may be prevented by monitoring the heartbeats of stroke survivors to look for irregularities beyond the standard 24-hour period after a stroke. Extended monitoring methods range from easily learned pulse measurements to traditional external recorders or high-tech electronic monitors implanted under the skin.  More »

Do you know the symptoms of a stroke?

Stroke symptoms come on suddenly, are a new experience, and have no explained cause. They can include dizziness, loss of balance, and trouble walking; vision problems, difficulty speaking or understanding others. (Locked) More »

Ask the doctor: Understanding aortic valve sclerosis

The aortic valve, which separates the left ventricle from the body’s main artery (aorta), sometimes thickens in people over age 65. Known as aortic valve sclerosis, it requires no treatment. But people with the condition should be monitored for heart disease.  (Locked) More »

New guidelines for the prevention of recurrent stroke

The risk of a stroke in people who have had a previous stroke or TIA is high. Updated prevention guidelines aim to lower the chance of a future “brain attack.” Highlights include revised blood pressure targets in the days following stroke; a focus on more intense cholesterol control; suggestions for better screening for diabetes and high blood pressure; and more specific diet and exercise recommendations. More »