Ischemic Stroke

Stroke is a brain injury caused by an interruption in blood flow. Brain tissue that does not get oxygen and nutrients from blood can die within minutes. The damage to the brain can cause a sudden loss in bodily functions. The types of function that are affected will depend on the part of the brain that is damaged. There are two blood flow problems that cause a stroke. Strokes may be ischemic or hemorrhagic.

  • Causes

    An ischemic stroke occurs when something stops the flow of blood. It may be a buildup or swelling of the walls of the blood vessels and/or something in the blood that becomes stuck in the blood vessel. A blockage in a small blood vessel will affect a smaller area of the brain. A blockage in larger blood vessels can block the flow of blood to several smaller blood vessels, leading to more brain damage.

    The blockage may be the result of one or more of the following:

    • Atherosclerosis—a build-up of fatty substances along the inner lining of the artery that gradually decrease the area the blood can flow through
    • A blood clot that has traveled from other parts of the body such as the neck or heart
    • Inflammation of the blood vessels

  • Definition

    Stroke is a brain injury caused by an interruption in blood flow. Brain tissue that does not get oxygen and nutrients from blood can die within minutes. The damage to the brain can cause a sudden loss in bodily functions. The types of function that are affected will depend on the part of the brain that is damaged.

    There are two blood flow problems that cause a stroke. Strokes may be ischemic or hemorrhagic.

    • An ischemic stroke is caused by a blocked blood vessel. It is the most common cause of stroke.
    • A hemorrhagic stroke is caused by a ruptured blood vessel.
    Hemorrhagic vs. Ischemic Stroke
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    Copyright © Nucleus Medical Media, Inc.

  • Diagnosis

    A physical exam will be done to look for muscle weakness, visual and speech problems, and movement difficulty. If possible, you will be asked about your symptoms and medical history.

    Images may be taken of your bodily structures. This can be done with:

    • CT scan
    • MRI scan
    • Magnetic resonance angiography
      (MRA)
    • CT angiogram (CTA)
    • Doppler ultrasound

    Blood tests can also help determine if there is a bleeding problem.

  • Prevention

    Many of the risk factors for stroke can be changed. Lifestyle changes that can help reduce your chance of getting a stroke include:

    • Exercise regularly.

    • Eat more
      fruits, vegetables
      , and
      whole grains
      . Limit dietary
      salt
      and
      fat
      .
    • Stop smoking
      .
    • Increase your consumption of fish.
    • Drink alcohol only in moderation: no more than 1-2 drinks per day.
    • Maintain a healthy weight.
    • Check blood pressure frequently
      . Follow your doctor's recommendations for keeping it in a safe range.
    • Take a low dose of aspirin if your doctor says it is safe.
    • Keep chronic medical conditions under control. This includes high cholesterol and diabetes.
    • Talk to your doctor about the use of a statins. These types of drugs may help prevent certain kinds of strokes in some people.
    • Seek medical care if you have symptoms of a stroke, even if symptoms stop.
    • If you abuse drugs, talk to your doctor about rehabilitation programs.

  • Risk Factors

    Certain factors increase your risk of stroke but can not be changed, such as:

    • Race—People of African American, Hispanic, or Asian/Pacific Islander descent are at increased risk.
    • Age: Older than 55 years of age
    • Family history of stroke

    Other factors that may increase your risk can be changed such as:

    • Drug abuse
      from cocaine, amphetamines, or heroin use
    • Smoking
    • Physical inactivity

    Certain medical condition that can increase your risk of stroke. Management or prevention of these conditions can significantly decrease your risk. Medical conditions include:

    • High blood pressure
    • High cholesterol levels—specifically high-LDL bad cholesterol
    • Low bone mineral density, especially in women
    • Obesity and metabolic syndrome
    • High blood homocysteine level
    • Atherosclerosis
    • Diabetes mellitus
      or impaired glucose tolerance
    • Atrial fibrillation
    • Blood disorders such as sickle cell disease
      and polycythemia
    • Vascular dementia
    • Disease of heart valves, such as
      mitral stenosis

    • Prior stroke or cardiovascular disease, such as
      heart attack
    • Peripheral artery disease
    • Transient ischemic attack (TIA)
      —a warning stroke with stroke-like symptoms that go away shortly after they appear
    • Conditions that increase your risk of blood clots such as:
      • Cancer
      • Certain autoimmune diseases
    • Migraine with aura
    • Having a blood vessel abnormality

    Risk factors specific to women include:

    • Previous pre-eclampsia
    • Use of birth control pills,
      especially if you are over 35 years old and smoke

    • Long-term use of
      hormone replacement therapy
    • Menopause
    • Pregnancy—due to increased risk of blood clots

  • Symptoms

    Symptoms occur suddenly. Exact symptoms will depend on the part of the brain affected. Rapid treatment is important to decrease the amount of brain damage. Brain tissue without blood flow dies quickly.

    Call for emergency medical services right away if you notice any of the following sudden symptoms:

    • Weakness or numbness of face, arm, or leg, especially on one side of the body
    • Confusion
    • Trouble speaking or understanding
    • Trouble seeing in one or both eyes
    • Lightheadedness, trouble walking, loss of balance, or coordination
    • Severe headache with no known cause

  • Treatment

    Immediate treatment is needed to open the blocked blood vessel. This should restore blood flow to the brain tissue and stop further damage.

    Treatment after immediate care will aim to:

    • Reduce the chance of later strokes
    • Improve function affected by the stroke
    • Overcome disabilities

    Supportive care may also include:

    • Oxygen therapy

    • Precautions to
      prevent choking