What is Stroke

Brain ScanA stroke occurs when the blood supply to part of your brain is interrupted or reduced, preventing brain tissue from getting oxygen and nutrients. Brain cells begin to die in minutes. A stroke is a medical emergency, and prompt treatment is crucial. Early action can reduce brain damage and other complications.


Symptoms

Signs and symptoms of stroke include:

  • Trouble speaking and understanding what others are saying. You may experience confusion, slur your words, or have difficulty understanding speech.
  • Paralysis or numbness of the face, arm or leg. You may develop sudden numbness, weakness or paralysis in your face, arm, or leg. This often affects just one side of your body. Try to raise both your arms over your head at the same time. If one arm begins to fall, you may be having a stroke. Also, one side of your mouth may droop when you try to smile.
  • Problems seeing in one or both eyes. You may suddenly have blurred or blackened vision in one or both eyes, or you may see double.
  • Headache. A sudden, severe headache, which may be accompanied by vomiting, dizziness or altered consciousness, may indicate that you’re having a stroke.
  • Trouble walking. You may stumble or lose your balance. You may also have sudden dizziness or a loss of coordination.

Seek immediate medical attention if you notice any signs or symptoms of a stroke, even if they seem to come and go or they disappear completely. Think “FAST” and do the following:

  • Face. Ask the person to smile. Does one side of the face droop?
  • Arms. Ask the person to raise both arms. Does one arm drift downward? Or is one arm unable to rise?
  • Speech. Ask the person to repeat a simple phrase. Is his or her speech slurred or strange?
  • Time. If you observe any of these signs, call 911 or emergency medical help immediately.

There are two main causes of stroke: a blocked artery (ischemic stroke) or leaking or bursting of a blood vessel (hemorrhagic stroke). Some people may have only a temporary disruption of blood flow to the brain, known as a transient ischemic attack (TIA), that doesn’t cause lasting symptoms.

Ischemic stroke

This is the most common type of stroke. It happens when the brain’s blood vessels become narrowed or blocked, causing severely reduced blood flow (ischemia). Blocked or narrowed blood vessels are caused by fatty deposits that build up in blood vessels or by blood clots or other debris that travel through your bloodstream and lodge in the blood vessels in your brain.

Some initial research shows that COVID-19 infection may be a possible cause of ischemic stroke, but more study is needed.

Hemorrhagic stroke

Hemorrhagic stroke occurs when a blood vessel in your brain leaks or ruptures. Brain hemorrhages can result from many conditions that affect your blood vessels. Factors related to hemorrhagic stroke include:

  • Uncontrolled high blood pressure
  • Overtreatment with blood thinners (anticoagulants)
  • Bulges at weak spots in your blood vessel walls (aneurysms)
  • Trauma (such as a car accident)
  • Protein deposits in blood vessel walls that lead to weakness in the vessel wall (cerebral amyloid angiopathy)
  • Ischemic stroke leading to hemorrhage

A less common cause of bleeding in the brain is the rupture of an abnormal tangle of thin-walled blood vessels (arteriovenous malformation).

Transient ischemic attack (TIA)

A transient ischemic attack (TIA) — or a ministroke — is a temporary period of symptoms similar to those you’d have in a stroke. A TIA doesn’t cause permanent damage. They’re caused by a temporary decrease in blood supply to part of your brain, which may last as little as five minutes.

Like an ischemic stroke, a TIA occurs when a clot or debris reduces or blocks blood flow to part of your nervous system.

Seek emergency care even if you think you’ve had a TIA because your symptoms got better. It’s not possible to tell if you’re having a stroke or TIA based only on your symptoms. If you’ve had a TIA, it means you may have a partially blocked or narrowed artery leading to your brain. Having a TIA increases your risk of having a full-blown stroke later.


Risk Factors

Potential stroke risk factors include:

  • Being overweight or obese
  • Physical inactivity
  • Heavy or binge drinking
  • Use of illegal drugs such as cocaine and methamphetamine
  • High blood pressure
  • Cigarette smoking or secondhand smoke exposure
  • High cholesterol
  • Diabetes
  • Obstructive sleep apnea
  • Cardiovascular disease, including heart failure, heart defects, heart infection or abnormal heart rhythm, such as atrial fibrillation
  • Personal or family history of stroke, heart attack or transient ischemic attack
  • COVID-19 infection

Other factors associated with a higher risk of stroke include:

  • Age — People age 55 or older have a higher risk of stroke than do younger people.
  • Race — African Americans have a higher risk of stroke than do people of other races.
  • Sex — Men have a higher risk of stroke than women. Women are usually older when they have strokes, and they’re more likely to die of strokes than are men.
  • Hormones — Use of birth control pills or hormone therapies that include estrogen increases risk.

Complications

A stroke can cause temporary or permanent disabilities, depending on how long the brain is without blood flow and which part was affected. Complications may include:

  • Paralysis or loss of muscle movement
  • Difficulty talking or swallowing
  • Memory loss or thinking difficulties
  • Emotional problems
  • Pain
  • Changes in behavior and self-care ability

Prevention

Ways to prevent your risk of stroke may include:

  • Controlling high blood pressure (hypertension)
  • Lowering the amount of cholesterol and saturated fat in your diet
  • Quitting tobacco use
  • Managing diabetes
  • Maintaining a healthy weight
  • Eating a diet rich in fruits and vegetables
  • Exercising regularly
  • Drinking alcohol in moderation
  • Treating obstructive sleep apnea (OSA)
  • Avoiding illegal drugs

Preventative medications may include:

  • Antiplatelet drugs. Platelets are cells in your blood that form clots. Anti-platelet drugs make these cells less sticky and less likely to clot. The most commonly used anti-platelet medication is aspirin. Your doctor can help you determine the right dose of aspirin for you.
  • Anticoagulants. These drugs reduce blood clotting. Heparin is fast acting and may be used short-term in the hospital. Slower-acting warfarin (Coumadin, Jantoven) may be used over a longer term. There are several other medications on the market that your