(Cerebrovascular Accident; CVA; Cerebral Infarct; Brain Attack)
Stroke is a brain injury. It occurs when the brain's blood supply is interrupted. Without oxygen and nutrients from blood, brain tissue dies quickly (in less than 10 minutes). This causes a sudden function loss.
A stroke occurs when blood flow to the brain is blocked (called ischemic stroke). This is caused by one of the following:
Sudden decreased blood flow
- Damage to a blood vessel supplying blood to the brain can occur suddenly from either:
Local blood clot
A build-up of fatty substances (]]>atherosclerotic plaque]]>) along the inner lining of the artery causes:
- Narrowing of artery
- Reduced elasticity
- Local inflammation
- Blood protein defects leading to increased clotting tendency
- Decreased blood flow in the artery
- A build-up of fatty substances (]]>atherosclerotic plaque]]>) along the inner lining of the artery causes:
- Clot in an artery supplying the brain
- Inflammatory conditions in the blood vessels (vasculitis)
A stroke may also occur if a blood vessel breaks and bleeds into or around the brain. This is called hemorrhagic stroke.
Hemorrhagic vs. Ischemic Stroke
These risk factors increase your chance of developing a stroke. Tell your doctor if you have any of these risk factors.
Risk factors you can affect:
- High blood pressure]]> (the number one risk factor for ischemic stroke)
- High blood homocysteine level
- ]]>Drug abuse]]> (heroin, ]]>cocaine]]>, amphetamines)
- Narrowing of arteries supplying the brain due to atherosclerosis
- ]]>High cholesterol levels]]>, particularly low-density lipoprotein (LDL) cholesterol
- ]]>Diabetes mellitus]]> or impaired glucose tolerance
- ]]>Atrial fibrillation]]> (abnormality of heart rhythm)
- Use of birth control pills, if you are over 35 years old and smoke
- Long-term use of ]]>hormone replacement therapy]]>
Risk factors you cannot affect:
- Prior stroke or pre-existing cardiovascular disease, such as ]]>heart attack]]>
- Prior ]]>transient ischemic attack]]> (TIA)—Some people experience a "warning stroke" or TIA. This is a temporary interruption of the brain's blood supply (mini-stroke). These are stroke symptoms that resolve completely within minutes. They may signal a very high risk of having a full-blown stroke in the near future.
- Age: 60 or older
- Family members who have had a stroke
- Gender: males are at greater risk
- Race: Black, Asian, Hispanic
- Blood disorders which increase clotting in ]]>sickle cell disease]]> and ]]>polycythemia]]>
- Valvular heart disease, such as ]]>mitral stenosis]]>
Symptoms occur suddenly. They differ depending on the part of the brain affected. Also, multiple symptoms can happen at the same time. If you notice any of the symptoms below, call emergency help right away. Getting help immediately is important, because brain tissue dies quickly when deprived of oxygen.
- Sudden weakness or numbness of face, arm, or leg, especially on one side of the body
- Sudden confusion
- Sudden trouble speaking or understanding
- Sudden trouble seeing in one or both eyes
- Sudden dizziness, trouble walking, loss of balance, or coordination
- Sudden severe headache with no known cause
Having a stroke is an emergency situation. Diagnosis includes:
- Neurological exams
- Electrocardiogram (ECG, EKG)]]>—a test that records the heart's activity by measuring electrical currents through the heart muscle
Brain and blood vessel imaging by:
- ]]>CT scan]]>—a type of x-ray that uses a computer to make pictures of the brain, helps doctors identify hemorrhagic versus ischemic stroke
- ]]>MRI scan]]>—a test that uses magnetic waves to make pictures of the brain
- Ultrasonography—a test that uses sound waves to examine the blood vessels feeding the brain
- Blood tests, especially homocysteine, prothrombin time, and other coagulation tests
Some tests may include:
- ]]>Arteriography]]> (angiography)—a catheter is placed in a blood vessel in the groin and threaded up to the brain, shows arteries in the brain
- ]]>Magnetic resonance angiography]]> (MRA)—shows brain blood vessels by mapping blood flow
- CT angiogram (CTA)—this test uses a CT scanner, gives images of the blood vessels inside the brain after a dye is injected into the veins
- Functional MRI—shows brain activity by picking up signals from oxygenated blood
- ]]>Doppler ultrasound]]>—shows narrowing of the arteries (carotid and vertebral) supplying the brain, evaluates flow of blood in brain
- ]]>Echocardiography]]>—a test that uses high-frequency sound waves (ultrasound) to examine the size, shape, and motion of the heart, shows if the clot comes from one of the heart's chambers
Immediate treatment is needed to:
- Dissolve a clot causing an ischemic stroke
- Stop the bleeding during a hemorrhagic stroke
Other treatment aims to:
- Reduce the chance of later strokes
- Improve functioning
- Overcome disabilities
- Given shortly after the start of symptoms—typically given within 3 hours by IV, or intraarterially (IA) within 6 hours
- Used in carefully selected patients
- Blood-thinning drugs (anticoagulants)
- Antiplatelet drugs
Other drugs are used to:
- Control blood pressure (]]>labetalol]]>, the first-line drug, or sodium nitroprusside)
- Reduce chance of additional clot formation (aspirin or similar medicines)
- Reduce brain swelling
- Correct ]]>irregular heart rhythm]]> (eg, ]]>atrial fibrillation]]>)
Other interventions during an acute stroke:
- ]]>Adequate oxygen]]>
- Precautions to prevent choking
- Frequent neurological examinations
Some procedures can be done to prevent damage or allow blood flow back into the affected area after a stroke:
- Extracranial/intracranial bypass—blood supply is rerouted around a blocked artery using a healthy scalp artery
- Craniotomy—done with a hemorrhagic stroke to relieve pressure build-up in the brain caused by swelling
- Embolectomy—a catheter is threaded through blood vessels to the clot; a special device will either mechanically remove the clot or deliver clot-dissolving medicine directly to the area
Other surgeries may be performed following a stroke or TIA to prevent a recurrence. Surgical techniques:
- ]]>Carotid endarterectomy]]>—fatty deposits are removed from a carotid artery (major arteries in the neck that lead to the brain)
- ]]>Carotid angioplasty]]> and ]]>stenting]]>—less invasive procedure, carotid artery is widened and a mesh tube is placed into the artery to keep it open
A study was done to compare endarterectomy to stenting. Even though endarterectomy is more invasive, it led to fewer deaths. It also had fewer repeat strokes than stenting within the first six months.
- Physical therapy—to regain as much movement as possible
- Occupational therapy—to assist in everyday tasks and self care
- Speech therapy—to improve swallowing and speech challenges
- Psychological therapy—to improve mood and decrease depression
To help reduce your chance of getting a stroke, take the following steps:
- Exercise regularly.
- Eat more fruits and vegetables]]>. Limit dietary ]]>salt]]> and ]]>fat]]>.
- ]]>Stop smoking]]>.
- Increase your consumption of fish.
- Drink alcohol only in moderation (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 (50-325 milligrams per day) 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.
- Stop the use of recreational drugs (cocaine, heroin, marijuana, amphetamines).
American Heart Association
National Stroke Association
Heart and Stroke Foundation of Canada
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11/20/06 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance: Mas JL, Chatellier G, Beyssen B, et al. Endarterectomy versus stenting in patients with symptomatic severe carotid stenosis. N Engl J Med. 2006;355:1726-1729.
12/16/2008 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance: Farquhar C, Marjoribanks J, Lethaby A, Suckling J, Lamberts Q. Long term hormone therapy for perimenopausal and postmenopausal women. Cochrane Database Syst Rev. 2008;CD004143.
10/9/2009 DynaMed's Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance: Mitchell PH, Veith RC, Becker KJ, et al. Brief psychosocial-behavioral intervention with antidepressant reduces poststroke depression significantly more than usual care with antidepressant: living well with stroke: randomized, controlled trial. Stroke. 2009;40:3073-3078.
Last reviewed November 2009 by ]]>J. Thomas Megerian, MD, PhD, FAAP]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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