A stroke is a sudden episode that may affect consciousness, sensation, and movement, which results from a blockage or rupture of a blood vessel in the brain. It causes symptoms that last for at least 24 hours. A stroke (known medically as a cerebrovascular accident or CVA) occurs when the blood supply to part of the brain is suddenly interrupted or when a blood vessel in the brain bursts, spilling blood into the spaces surrounding brain cells. Brain cells die when they no longer receive oxygen and nutrients from the blood or there is sudden bleeding into or around the brain.
There are two main types -- ischemic and hemorrhagic. The ischemic type occurs when there is a lack of oxygen- or nutrient-rich blood to a part of the brain for a long enough period of time that brain tissue dies. This lack of blood flow occurs because of a severely narrowed or blocked artery in the neck or brain. The ischemic type makes up 80 percent of all cases.
The second type is a hemorrhagic stroke. This type occurs because of bleeding in the brain from a broken blood vessel. For each type -- ischemic and hemorrhagic -- the causes can vary.
Risk Factors
Risk factors are conditions or behaviors that increase your chances of getting a certain disease. Some risk factors can be treated or controlled, and some cannot.
Risk factors for this condition that you cannot change include:
- Age (the risk tends to increase with age)
- Gender (men are more likely to have a stroke, but women are more likely to die of one)
- Race/ethnicity (African Americans are more likely to have a stroke than people from other ethnic groups)
- Family history of stroke
- Personal history of a stroke, TIA, or heart attack.
Some of the most important treatable or controllable risk factors are:
- Sudden numbness or weakness (especially on one side of the body)
- Sudden confusion, or trouble speaking or understanding speech
- Sudden trouble seeing in one or both eyes
- Sudden trouble with walking, dizziness, or loss of balance or coordination
- Sudden severe headache with no known cause.
In order to make a diagnosis, a healthcare provider will typically begin by asking a number of questions (such as those concerning the patient's medical history) and perform a physical exam. If the healthcare provider believes that a person has had a stroke, he or she may order additional tests. After a doctor has made a diagnosis, he or she may recommend other tests to help determine the cause of the stroke.
Some tests that doctors may use for diagnosing a stroke and/or identifying its cause include:
- CT scan
- Magnetic resonance imaging (MRI)
- Carotid Doppler ultrasound
- Carotid arteriography
- Cerebral angiography (also known as a cerebral angiogram, cerebral arteriogram, or digital subtraction angiography)
- Magnetic resonance angiogram (MRA) or functional magnetic resonance imaging (fMRI)
- Transcranial Doppler
- Electrocardiogram (EKG)
- Echocardiogram
- Lumbar puncture
- Electroencephalography (EEG).
Each year, about 700,000 people in the United States have a stroke. Over 150,000 of these people die as a result, making it the third-most common cause of death in the U.S. Delaying treatment can result in lasting damage to your brain, or even death. The sooner treatment begins, the better your chances of recovering.
The goals of stroke treatment are to:
- Quickly restore blood flow to the brain (in those people with an ischemic stroke) or stop the bleeding (in those people with hemorrhagic stroke)
- Continuously monitor your vital signs to detect and treat stroke complications
- Make lifelong changes to reduce the chances of another stroke.
Depending on the situation and the type of stroke (ischemic versus hemorrhagic), specific treatment options may include:
- Medications, such as thrombolytic ("clot-busting") drugs
- Surgery
- Stroke rehabilitation and lifestyle changes.
Generally, a stroke can cause five types of disabilities, which include:
- Paralysis or problems controlling movement
- Sensory disturbances (including pain)
- Problems using or understanding language
- Problems with thinking and memory
- Emotional disturbances.
Steps for effective prevention involve:
- Knowing your risk factors
- Monitoring your health and making lifestyle changes to reduce your risk
- Possibly taking medication or having a procedure
- Knowing the signs of a stroke.
Comparing a TIA to a Stroke
A
transient ischemic attack (
TIA for short) and a stroke are very similar. In fact, a
TIA is also known as a transient stroke, or "
mini-stroke." The difference comes down to timing. By definition, a stroke produces symptoms that last for at least 24 hours. A TIA produces symptoms that improve after a shorter period of time (usually within 30 minutes).
Statistics on this topic include the following:
- More than 700,000 strokes occur each year in the United States
- It is the third-leading cause of death in the country
- It causes more serious long-term disabilities than any other disease
- Nearly three-quarters of all strokes occur in people over the age of 65
- The risk of having one more than doubles each decade after the age of 55.
For African Americans, stroke is more common and more deadly -- even in young and middle-aged adults -- than for any ethnic or other racial group in the United States.
Learning about strokes can help you act in time to save a co-worker, friend, or relative. And making changes in your lifestyle can help you prevent a stroke.
