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

Red meat, TMAO, and your heart

Researchers are finding that a substance called trimethylamine N-oxide (TMAO), produced when the body digests red meat, is linked to health ills such as cardiovascular disease and kidney disease. Experts say people with high levels of TMAO in their blood may have double the risk of cardiovascular disease, compared with people who have lower levels. (Locked) More »

Ultra-processed foods linked to poor heart health

Ultra-processed foods linked to poor heart health Research we're watching Eating ultra-processed foods — such as packaged snacks, sugary cereals and drinks, chicken nuggets, and instant soup — may leave people more prone to heart disease and an early death, two new studies suggest. Both were published May 29 in The BMJ. (Locked) More »

Ministroke: A warning sign of a major problem

Short-lived but odd symptoms—such as one-sided weakness, trouble seeing, or problems speaking—may be symptoms of a transient ischemic attack (TIA), also known as a ministroke. Caused by a temporary lack of blood in the brain, a TIA is a warning sign for a future stroke. About 15% of people with TIAs go on to have a stroke in the next three months, with half occurring in the first two days. People with TIA symptoms should call 911 for an urgent medical evaluation, as doctors may be able to prevent a permanent stroke from occurring. (Locked) More »

Deep-vein blood clots: What you need to know

A blood clot that forms in a vein, known as venous thromboembolism (VTE), is the third most common cause of cardiovascular death. Most of these fatalities occur when a clot travels from the leg to the lung, causing a pulmonary embolism. VTE occurs in an estimated one in 1,000 people in the United States every year. Factors that increase a person’s risk of heart disease, such as age, smoking, and being overweight or obese, also raise the risk of VTE. Other contributing factors include recent surgery, hospitalization, injury to a vein, and decreased blood flow, usually caused by immobility. (Locked) More »

Lessons about brain health from a landmark heart study

The Framingham Heart Study—the longest running and best-known study of the causes of heart disease—has also revealed important clues about brain disorders, including stroke, cognitive decline, and dementia. In addition to linking high blood pressure with a higher risk of stroke, the study has confirmed that atrial fibrillation and an enlarged left ventricle contribute to stroke risk. The multigenerational study has also affirmed the importance of exercise and social connections for staving off cognitive decline. More »