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Time Is Brain: Seconds Matter After a Stroke

Think of a stroke like a lightning strike. “It happens extremely quickly and leaves a big effect,” says Omar Kass-Hout, MD, medical director of stroke and interventional neurology at UNC Rex Healthcare.

This ability to cause quick devastation is why strokes must be treated with as much speed as possible. Stroke is a leading cause of adult disability and the fifth-leading cause of death in the United States. But fast treatment can—and does—save lives and brain tissue.

Read on to learn what happens in the seconds, minutes, hours and days after a stroke.

What Happens During a Stroke: The Brain Attack

A stroke occurs when blood flow to the brain is suddenly interrupted. It usually happens because a blood clot dislodges from elsewhere in the body and becomes stuck in the arteries that supply the brain with fresh, oxygenated blood. When those arteries become blocked and cannot deliver oxygen, brain cells immediately start to die.

Most strokes—more than 85 percent—are ischemic, meaning brain cells are damaged by a lack of oxygen supply caused by a blockage in the arteries. The less common type of stroke is called hemorrhagic, when a weakened blood vessel ruptures, causing blood to spill into the brain, also damaging cells.

What Happens in the Seconds and Minutes After a Stroke

Once a stroke happens, neurons—brain cells in charge of transmitting signals to the body—start dying.

Neurologists believe that a person’s brain has as many as 100 billion neurons. Research shows the typical person loses 1.9 million neurons each minute that a stroke is untreated. The types of neurons affected by a stroke, and therefore the parts of the body affected, are dependent on where in the brain it happens. The extent of damage depends on how long the stroke lasts.

“It’s a chain of events comparable to a fire in a forest,” Dr. Kass-Hout says. “When an artery is damaged in the brain, it affects every smaller artery that leads away from it. It’s like a fire spreading from one tree to another, killing some trees and leaving others damaged.”

Depending on the severity of the stroke, you can begin to see the effect of these damaged neurons in a person’s behavior almost immediately.

Spot the signs of stroke by remembering the acronym FAST:

  • Face drooping: Trouble moving one side of the face; if you try to smile, it looks crooked.
  • Arm weakness: Difficulty using the arms; you might not be able to lift them to the same height.
  • Speech difficulty: Slurring words, saying things that sound like gibberish, difficulty talking.
  • Time to call 911: Immediately call for help and note what time it is when you call so that you can relay this information to healthcare workers.

Dr. Kass-Hout says it doesn’t matter when you notice these symptoms—if they just started, or it’s the middle of the night, or you’re away from home—call 911 immediately so that treatment can begin as soon as possible.

It’s critical to call 911 instead of taking the person to a hospital yourself. Paramedics can begin gathering important information to relay to physicians and can help determine which hospital the person should be transported to for the care he or she needs.

It’s important to note that a transient ischemic attack (TIA), also known as a ministroke, produces symptoms similar to a full stroke. A TIA is a temporary block of blood flow to the brain in which the clot usually dissolves or gets dislodged quickly on its own. Because blood flow is not blocked for very long, TIAs do not cause significant brain cell damage. But a TIA is a major warning sign of stroke and should be taken equally seriously—call 911.

What Happens in the Hours After a Stroke

“The longer the time that brain cells do not have the nutrients they need, the more they are damaged and killed,” Dr. Kass-Hout says. “We try to save the cells that are still alive but not functioning. This is all dependent on how quickly we see the patient once the stroke has started.”

When a person arrives at a hospital, doctors use a CAT scan to see images of the brain and quickly determine what kind of stroke has occurred. An ischemic stroke patient who has arrived at the hospital within 4 ½ hours of the stroke is likely to receive the drug tPA, given intravenously to break up the clot that is blocking blood flow to the brain.

Some patients undergo a newer procedure called endovascular thrombectomy (EVT), in which a small tube called a catheter is inserted into an artery in the patient’s groin. Using X-ray imaging, doctors maneuver the tube through the arteries to the clot. They can then grab and remove the clot using a tool called a stent to restore blood flow. EVT can be helpful to patients up to 24 hours after a stroke.

“Unfortunately, we cannot bring back the brain cells that have died,” Dr. Kass-Hout says. “But there are dysfunctioning cells that we can save by restoring blood flow and oxygen supply. The sooner this happens, the more long-term damage we can prevent.”

Dr. Kass-Hout says there are more treatment options for an ischemic stroke patient than for a hemorrhagic stroke patient, as hemorrhagic strokes tend to be more severe and have a higher mortality rate. Some hemorrhagic strokes are the result of ruptured aneurysms, which are caused by weakening of the arterial wall. To find and study the aneurysm, doctors can use catheters to explore a patient’s arteries. They can then use the catheter to put in place a tool called a coil to prevent the artery from rupturing more. Sometimes surgery is required to prevent the blood vessels from leaking or rupturing again.

What Happens in the Days After a Stroke

Once treatment has been administered, patients are watched closely, and two-thirds of stroke patients are admitted to the hospital. Each patient’s recovery and care will be different, but before they leave the hospital, they meet with a range of therapists to determine a rehabilitation plan.

Doctors will work to identify risk factors that led to the stroke or may cause another stroke in the future, including diabetes, high blood pressure, high cholesterol and atrial fibrillation, and they will prescribe medications or possibly even surgery to help address them.

Dr. Kass-Hout says patients who had severe strokes, due to blockage of large arteries in the brain, return to their version of normal after a stroke about half of the time. Of those who have lasting effects from a stroke, they can range from mild to severe. A variety of services are available to help patients progress and regain functions that are affected, including physical, occupational and speech-language therapies. Rehabilitation can be a long process, and it varies with each person. If you or a loved one is recovering from a stroke, UNC REX’s recovery team can help.


Talk to your primary care physician about what you can do to prevent a stroke. If you don’t have a doctor, find one near you.