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

Duration of atrial fibrillation and risk of stroke

Even intermittent (paroxysmal) atrial fibrillation may increase a person’s risk of stroke. Measuring afib burden (the amount of time spent in afib) may help doctors to better assess a person’s need for stroke prevention strategies. More »

How atrial fibrillation may affect your brain

People with atrial fibrillation—a heart rhythm disorder that causes a rapid, irregular heart rate—may face an increase risk of thinking and memory problems. Atrial fibrillation causes blood to pool in the heart’s upper left chamber, which may form clots that can travel to the brain, causing a stroke. But tiny clots can cause silent, unnoticed strokes. Over time, these stroke gradually injure part of the brain involved with thinking and memory. (Locked) More »

Harnessing big data to help the heart

Advanced technologies are beginning to transform doctors’ ability to screen for cardiovascular disease. Examples include the analysis of data from smartphones and other devices using machine learning to predict a person’s risk of disease. Two promising applications include retina scans to predict heart disease and pulse monitoring with a smartwatch to detect atrial fibrillation, a common cause of stroke. Possible future applications include capturing varied data from electronic health records, such as electrocardiograms, echocardiograms, blood test results, and genetic information. (Locked) More »

Tuning in: How music may affect your heart

Music engages many different areas of the brain, which may explain why listening to music may boost exercise ability, ease stress and anxiety, and enhance recovery from heart surgery and strokes. Listening to or creating music (playing an instrument or singing) triggers the release of a brain chemical that makes people feel engaged and motivated, which may allow people to exercise longer. Relaxing music may lower a person’s heart rate, breathing rate, and blood pressure—perhaps because sound processing begins in the brainstem, which also controls the heart rate and respiration. Patient-selected music shows more benefit than music selected by someone else. (Locked) More »