Stroke

Every year, according to the American Association of Neurological Surgeons (AANS), over half a million Americans suffer a stroke. A stroke (also called a "brain attack") occurs when one of the blood vessels that carry oxygen to the brain either becomes clogged or bursts. (Read about "Vascular System: Arteries and Veins")

When this happens, the nerve cells in the affected part of the brain can't function. (Read about "The Brain") As a result, AANS says whatever body part those nerve cells control will be impaired as well. That's why stroke affects different people in different ways, sometimes causing problems with speech, for example, sometimes problems with movement, sometimes problems with memory (Read about "Dementia"), or sometimes there are several impairments in combination.

Risk factors

There are a number of risk factors that can put someone at a higher risk of having a stroke.

Our STROKE RISK ASSESSMENT can help you learn more about your own stroke risk factors.

Simply click on the link for the form. Fill it out online to learn more about how specific things affect the risk of stroke. When you're done, you may want to print it out and share it with your doctor. Any information you enter will NOT be saved once you close the window. This is to protect your privacy. When you're done, simply close the form window, and continue reading.

The National Institute on Aging says men are at a higher risk than women; African Americans (Read about "Minority Health") also face a higher risk; and our risk increases, as we get older.

Other risk factors include:

• High blood pressure - The American Stroke Association (ASA) considers this the most important risk factor for stroke. The only way to find out for sure if you have high blood pressure is to have it checked by a healthcare professional. (Read about "High Blood Pressure")
• Personal medical history that includes heart disease and/or diabetes. (Read about "Coronary Heart Disease" "Diabetes")
• Family history of stroke (Read about "Family Health History")
• Elevated cholesterol or triglyceride levels (Read about "Cholesterol")
• Smoking - According to the American Stroke Association, smokers can reduce their risk of stroke by quitting, even if they've been long-time smokers. (Read about "Quit Smoking")
• Atrial fibrillation (AF) - The American Stroke Association says AF is a type of heart rhythm problem that increases the risk of stroke. (Read about AF in "Arrhythmia")
• Patent foramen ovale (PFO) which is an opening between the two upper chambers of our heart that fails to completely close and seal after we are born. (Read about "Patent Foramen Ovale")

If you are considered to be at risk of stroke, there are several tests that can be used, including:

• Echocardiography - this shows the size, structure, and movement of various parts of your heart. It can be used to check for blood clots. (Read about "Cardiovascular Tests")
• Carotid ultrasound exam - this checks the arteries in your neck for narrowing or stenosis (Read about "Ultrasound Imaging")
• Abdominal ultrasound - this looks for aortic aneurysm in the abdomen (Read about "Aneurysms")
• Ankle brachial index test - this looks for blocked arteries in your legs, which is called peripheral artery disease (Read about "Peripheral Arterial Disease")
• Computed tomography angiogram (CTA) - this is a CT scan that can be used to diagnose problems of the brain and brainstem (Read about "CT Scan - Computerized Tomography" "The Brain")
• Cerebral angiography or arteriogram - this is an x-ray (Read about "X-rays") of the blood vessels of the brain
• Magnetic resonance angiography (MRA) - this is a special type of MRI (Read about "MRI - Magnetic Resonance Imaging") that can be used to see the blood vessels in your neck or brain.

Your doctor may also order tests to see if there are blockages or other problems of the heart. (Read about "Cardiovascular Tests") If any tests do indicate blockages in the brain, heart or elsewhere, your doctor may recommend treatment options, including lifestyle changes, medications, and/or surgery.

Warning signs

Stroke warning signs may be temporary. They may go away after a few hours. They may even go away in a few minutes. But regardless of how long the symptoms last, AANS says it's essential that anyone experiencing the symptoms of stroke seek immediate medical help. The main symptoms include:

• Sudden weakness or numbness of the face, arm or leg, especially on one side of the body
• Sudden dimness or loss of vision, especially if this happens in just one eye (Read about "The Eye")
• Sudden severe headache with no apparent cause (Read about "Headaches")
• Loss of speech, problems talking, or problems understanding speech (Read about "Aphasia")
• Unexplained dizziness or falls, especially if some of the other symptoms are present

The National Stroke Association says you can use the acronym FAST:

• 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?
• Speech - Ask the person to repeat a simple phrase. Is their speech slurred or strange?
• Time - If you observe any of these signs, call 9-1-1 immediately.

The Food and Drug Administration (FDA) says other symptoms that are less common, but still important, are sudden nausea, vomiting, brief loss of consciousness or decreased consciousness, such as fainting (Read about "Syncope/Fainting") and convulsions. There is also what is called a "silent stroke," in which there may be no noticeable symptoms.

Ischemic stroke

Some 80 percent of all strokes are caused by blockages of the blood vessels in the brain. They are called ischemic strokes. Ischemic strokes are also divided into two categories, according to the American Stroke Association. They are:

• Thrombotic - these are the result of two things, the slow narrowing of the arteries as fatty deposits build up and the formation of a clot that then lodges in this narrowed opening. (Read about "Arteriosclerosis & Atherosclerosis") ASA says uncontrolled high cholesterol is a risk factor for this type of stroke. (Read about "Cholesterol")
• Embolic - these happen when a clot forms somewhere else in the body, breaks free and eventually lodges in the brain. For example, a type of arrhythmia called atrial fibrillation affects the heart's ability to pump blood, so it may pool and clot. The clot can travel to the brain. In fact, ASA says about 15 percent of strokes occur in people with atrial fibrillation. (Read about "Arrhythmia")

Thrombolysis is the term used for the breaking up of a clot with drug therapy. Ischemic strokes can be treated with a drug called tPA, according to National Institute of Neurological Disorders and Stroke (NINDS). It dissolves blood clots obstructing blood flow to the brain. To be evaluated and receive treatment however, patients need to get to the hospital as quickly as possible. Potential dangers from the drug include internal bleeding in the brain. Some patients may be helped by a procedure that involves the use of a tiny device that can remove the blood clot or clots that are blocking the artery.

After an ischemic stroke, blood thinners, antiplatelet drugs or anticoagulants may be prescribed. If a doctor determines that a stroke has been caused by a blockage of a blood vessel leading to the brain, surgery may be needed too. (Read about "Neurosurgery") In a procedure called carotid endarterectomy, surgeons open up the carotid artery in the neck and scrape out plaque. Surgeons also may open up a clogged carotid artery with a small balloon and insert a small tube called a stent to keep the artery open. (Read about "Angioplasty") Following surgery, drugs that prevent more clots from forming may be prescribed. For some patients, who are considered at high risk of having a stroke, carotid artery surgery may be recommended as a prophylactic measure, to prevent a stroke from occurring. Depending on the severity of the stroke, and on the area of the brain impacted, physical rehabilitation may be necessary. (Read about "Rehabilitation") Again, since treatment and rehabilitation should begin as soon after a stroke as possible, it's essential for everyone to recognize the symptoms of a stroke and get help right away.

Hemorrhagic stroke

According to the American Stroke Association, 20 percent of strokes are hemorrhagic strokes. They happen when a weakened vessel ruptures and bleeds into the surrounding brain. This type of stroke can be caused by a head injury (Read about "Head Injury"), for example, or if an aneurysm (a blood-filled pouch that forms on weak spots in the artery wall) bursts. (Read about "Aneurysms") This type of stroke can also be caused by an arteriovenous malformation (AVM), a congenitally malformed mass of thin-walled blood vessels. (Read about "Vascular Lesions of the Central Nervous System") Subarachnoid hemorrhage refers to bleeding in the space between the surface of the brain and the skull. Intracerebral hemorrhage refers to bleeding that occurs within the brain tissue. A hemorrhagic stroke is very dangerous because the accumulated blood from the burst artery may put pressure on surrounding brain tissue and interfere with how the brain functions.

Treatment for hemorrhagic stroke depends on the cause of the hemorrhage and how much damage was done to the brain. With hemorrhagic stroke, doctors want to clot the blood and stop the bleeding. Medication can be used to do this. FDA says hemorrhagic stroke can also be treated with surgery that removes abnormal blood vessels or places a clip at the base of an aneurysm. Aneurysms may also be treated by using catheters. Surgery can also be used to remove the AVM, if this is the cause of the stroke. If high blood pressure caused the hemorrhagic stroke, medication may be used to bring blood pressure down. Depending on the severity of the stroke, and on the area of the brain impacted, physical rehabilitation may be necessary. Again, since treatment and rehabilitation should begin as soon after a stroke as possible, it's essential for everyone to recognize the symptoms of a stroke and get help right away.

TIA's and "silent" strokes

AANS says many people are unaware of the warning signs of a stroke. This is particularly true in the case of a transient ischemic attack (TIA). A TIA is a temporary situation in which you suddenly experience the symptoms of a stroke, but then the symptoms go away after a few minutes. People often ignore a TIA, thinking the problem has disappeared. This can be a fatal mistake because a TIA is serious warning. In fact, according to AANS, approximately 10 to 15 percent of patients who have TIA's will suffer a stroke within one year of the first attack.

In addition, there is also a "silent stroke." The American Stroke Association says silent strokes are far more common than once thought. Basically, silent strokes occur when small blood vessels in the brain become blocked or rupture. A silent stroke is not accompanied by the classic warning signs of stroke; in fact, someone experiencing silent strokes may not even be aware of it. But eventually, as blood and oxygen supply to the brain diminishes, cells die. This can lead to problems with memory or concentration. It can also create mood changes and lead to depression. (Read about "Depressive Illnesses")

Because of this, the American Stroke Association says seniors should be monitored more carefully for depression since depression may indicate that a silent stroke has already occurred. (Read about "Depression and Seniors")

After a stroke

Treatment following a stroke depends on the type of stroke involved.

• TIA - If a transient ischemic stroke is suspected, there will be tests to determine the cause. Tests can include a physical examination, CT scan, MRI. (Read about "CT Scan - Computerized Tomography" "MRI - Magnetic Resonance Imaging") Arteriography, which can provide x-ray images of blood vessels, may also be used to look for problems in the arteries of the brain. (Read about "X-rays") Depending on the results of these tests, medications may be used to reduce the risk of more TIA's or a full stroke. Medications can include antiplatelet drugs or anticoagulants to prevent blood clots from forming. For some people, carotid endarterectomy and/or carotid stenting, may be recommended to keep the carotid artery clear and open.
• Ischemic stroke - Following an ischemic stroke, the goal is to quickly restore blood flow to the brain. In appropriate patients, the drug tPA can be used to dissolve blood clots. Surgery with a tiny device may be used in some cases for clot removal. After initial treatment, blood thinners, antiplatelet drugs or anticoagulants may be prescribed to prevent additional blood clots from forming. For some people, carotid endarterectomy and/or carotid stenting may be recommended to keep the carotid artery clear and open.
• Hemorrhagic stroke - Following a hemorrhagic stroke, medication may be used to clot the blood and stop the bleeding. Surgery may also be used for treatment and/or prevention of another stroke Options include clipping or embolization to keep the aneurysm from bursting. If the stroke was caused by an arteriovenous malformation (AVM), surgery to remove the AVM may also be needed.

Although stroke is a disease of the brain, it can affect the entire body. A common disability that results from stroke is complete paralysis on one side of the body, called hemiplegia. A related disability that is not as debilitating as paralysis is one-sided weakness or hemiparesis. Stroke may cause problems with:

• thinking
• awareness
• attention
• learning
• judgment
• memory

Stroke survivors often have problems understanding or forming speech. (Read about "Aphasia") A stroke can lead to emotional problems. Stroke patients may have difficulty controlling their emotions or may express inappropriate emotions.

Depression can also develop after a major stroke. In fact, according to the National Institutes of Health, an estimated 10-27 percent of people who suffer a stroke also experience major depression and an additional 15-40 percent experience depressive symptoms within two months following the stroke. It is important to monitor patients for signs of depression. (Read about "Depressive Illnesses")

Stroke survivors may also have numbness or strange sensations. (Read about "Paresthesia") The pain is often worse in the hands and feet and is made worse by movement and temperature changes, especially cold temperatures.

Generally, there are three treatment stages following a stroke: therapy immediately after the stroke, prevention of another stroke and post-stroke rehabilitation. Acute stroke therapies try to stop a stroke while it is happening by quickly dissolving the blood clot causing an ischemic stroke or by stopping the bleeding of a hemorrhagic stroke. Therapies to prevent a recurrent stroke are based on treating an individual's underlying risk factors for stroke, such as hypertension, atrial fibrillation and diabetes. (Read about "Hypertension: High Blood Pressure" "Arrhythmia" "Diabetes") Post-stroke rehabilitation (Read about "Rehabilitation") helps individuals overcome disabilities that result from stroke damage. Medication or drug therapy is the most common treatment for stroke, according to NINDS. NINDS says that the most popular classes of drugs used to prevent or treat stroke are antithrombotics (antiplatelet agents and anticoagulants) and thrombolytics.

It is also important to make lifestyle changes to reduce the risk of having another stroke. According to NINDS, about 25 percent of people who recover from a first stroke will have another within five years, and the chance of death and disability increases with each stroke. So it's essential that you work to lower your stroke risk through lifestyle changes and medication that lowers blood pressure and cholesterol.

Related Information:

    The Heart & Cardiovascular System

    Cardiovascular Tests

    Peripheral Arterial Disease

    Thrombophilia

    Deep Vein Thrombosis

    Glossary of Heart Terms

    Glossary of Stroke Terms