Stroke

What Is A Stroke?

A stroke occurs when the blood flow to a part of the brain is disrupted. Not enough blood reaches the affected part of the brain. The cells in the part of the brain affected do not get enough oxygen and begin to die.

Damage to the brain can cause loss of speech, vision, or movement in an arm or a leg, depending on the part of the brain that is affected.

There are two main types of stroke:

• Stroke caused by a blockage in the artery supplying blood to a particular region of the brain (called cerebral infarction).This is the most common type of stroke.
• Stroke caused by bleeding within the brain (called intracerebral hemorrhage).

In addition, some people experience brief warning signals that a major stroke is going to happen in the future. The medical term to describe these symptoms is transient ischemic attack or TIA. Sometimes called “mini-strokes”, TIAs are exactly like a stroke, but they last only a few minutes (or sometimes as long as an hour) and leave no disability.

In many cases, a stroke will affect only one side of the body:

• A stroke that damages the right side of the brain will affect the left side of the body.
• A stroke that damages the left side of the brain will affect the right side of the body.

1. Stroke Caused By Blocked Blood Flow

About 85 percent of all strokes happen because not enough blood gets to the brain. Blood flow stops when an artery carrying blood to the brain becomes blocked. The technical name for this type of brain attack is cerebral infarction. It is also called ischemic stroke. “Ischemic” refers to a condition caused by a decreased supply of oxygenated blood to a body part.

The blockage can be caused either by a blood clot that forms in an artery in the brain, or by a blood clot formed elsewhere in the body that travels through the bloodstream to the brain. If this clot becomes stuck in an artery in the brain, a stroke can result.

Clots are more likely to form in arteries that are damaged by atherosclerosis, also called “hardening of the arteries,” due to the buildup of cholesterol and other thick, rough, fatty deposits in the arteries.

The blockage also can be caused by a small piece of tissue, usually a blood clot, that has traveled through the bloodstream from elsewhere in the body.

In ischemic stroke, one of two major arteries is usually involved:

• The carotid artery (most commonly involved site)
• The basilar artery

The carotid arteries start at the aorta (just above the heart) and lead up through the neck, around the windpipe, and into the brain. The basilar artery is formed at the base of the skull from the arteries that run up along the spine, and branches off in the brain.

2. Stroke Caused By Bleeding In The Brain

The other 15 percent of strokes happen when an artery carrying blood to the brain bursts suddenly. The bursting can happen because of a weak spot in the wall of an artery called an aneurysm. This type of brain attack is called a hemorrhagic stroke.

Two kinds of stroke are caused by bleeding in the brain:

• A subarachnoid hemorrhage occurs when a blood vessel on the brain bursts and bleeds into the fluid-filled space between the brain and the skull. This type of stroke can happen at any age.
• An intracerebral hemorrhage occurs when an artery bursts inside the brain, flooding the surrounding brain tissue with blood. This type of stroke is often associated with high blood pressure.

What Are “Mini-Strokes”?

A “mini-stroke” is exactly like a stroke, but it lasts only a short time and leaves no disability. The term for this event is transient ischemic attack or TIA.

A TIA happens when a blood clot clogs an artery temporarily, cutting off blood flow and, consequently, the supply of oxygen to cells. But the difference between a TIA and a stroke is that, with TIA, the blood clot dissolves on its own and blood flow is restored before permanent damage to the brain can occur.

TIAs are an extremely important warning sign for stroke and should never be ignored.

What Are The Signs Of A Stroke?

The warning signs of stroke are:

• Sudden weakness or numbness of the face, arm, and leg on one side of the body
• Sudden loss of vision or dimmed vision, particularly in one eye
• Loss of speech, or trouble talking or understanding speech
• Sudden, severe headaches with no apparent cause
• Unexplained dizziness, unsteadiness, or sudden falls, especially if accompanied by any of the previous symptoms

Most severe headaches are not a sign of stroke. Migraine, which can cause quite severe and sometimes alarming headaches, is very common and affects about one in five people.

What Do Different Parts Of The Brain Do?

The brain is a very complicated organ. Although it is a relatively small part of the body, it uses one-quarter of the blood supply.

When a person is right handed, the left side of the brain is dominant. About 90 percent of left-handed people have the right side of the brain dominant.

What Increases The Risk For A Stroke?

Anybody can have a stroke, but certain factors place a person at higher risk. Some factors that increase the risk of stroke cannot be changed, while others are linked to lifestyle.

Risk Factors That Cannot Be Changed

Some risk factors for stroke cannot be changed:

• Age – The older a person gets, the greater the risk of stroke.
• Sex – Men are more likely to have a stroke than women are.
• Race – Blacks have a greater risk of stroke than whites do.
• Diabetes– People with diabetes mellitus are more at risk.
• A history of migraine headaches– Recent studies indicate that women who experience migraines are at higher risk for ischemic stroke (stroke caused by a blockage in a blood vessel).
• A prior stroke -Someone who has had a stroke has a slightly increased risk for another.

Risk Factors That Can Be Changed With Medical Treatment

The major risk factors for stroke that medical treatment can change are:

• High blood pressure– High blood pressure has no warning signs, so regular blood pressure checks are important. The condition can be easily and successfully controlled with medication.

  For more detailed information on how to lower your blood pressure, GO TO High Blood Pressure.

• TIAs, or “mini-strokes” – A surprising number of people ignore the symptoms of TIAs, which are warning signs that a stroke may be about to happen. But people who have had TIAs can take steps to help prevent a major stroke.
• Berry aneurysms – These are small, sac-like areas within the wall of a cerebral artery. Some people are born with berry aneurysms. They occur most often at the junctures of vessels at the base of the brain. Berry aneurysms may rupture without warning, causing bleeding within the brain.
• Cardiovascular disease – Certain disorders of the heart and/or blood vessels, such as atherosclerosis and atrial fibrillation, can produce blood clots that may break loose and travel to the brain.

Risk Factors That Can Be Changed By Lifestyle Modifications

Risk factors for stroke than can be controlled by changes in lifestyle are:

• High blood cholesterol levels – Studies have shown that lowering cholesterol levels can reduce the risk of stroke by as much as 30 percent. Keeping cholesterol low can reduce the risk of blood clots and buildup within the walls of an artery in the brain.

  For more information about reducing your blood cholesterol levels, GO TO How To Lower Your Cholesterol Level.

• Cigarette smoking – Cigarette smoking has been linked to heart attacks, strokes, artery disease in the legs, and lung cancer. Nicotine raises blood pressure, carbon monoxide reduces the amount of oxygen the blood can carry to the brain, and cigarette smoke makes the blood thicker and more likely to clot. It is never too late to give up smoking.
• Taking birth control pills if you are a smoker – Research has proven that smoking and taking birth control pills significantly increases a woman’s risk for stroke. Together, they can cause blood clots to form. Women who take birth control pills should not smoke.
• Drinking large amounts of alcohol – Frequent intoxication can make a person more likely to experience bleeding in the brain. Also, alcohol in large amounts can raise blood pressure.
• Obesity – Being overweight increases your risk of having a stroke, along with other health problems.
• Lack of exercise – Moderate exercise can help keep blood pressure and cholesterol levels within normal ranges.
• Poor diet – A diet high in fat can cause conditions within the body that can contribute to a stroke.

How Is A Stroke Treated?

A stroke is a medical emergency, regardless of whether it is a major stroke or a short-lasting TIA. A person suffering a stroke should be taken immediately to a hospital emergency department.

The ability to pinpoint quickly the precise location of a stroke and determine the extent of damage is critically important in treatment decisions. A stroke caused by a blocked artery is treated in an entirely different way than a stroke caused by bleeding within the brain.

The key to survival and recovery is prompt medical treatment.

Tests That May Be Performed At The Hospital

Scans of the brain are performed to confirm a diagnosis of stroke and to determine the type of stroke. This is important since the treatment of different types of stroke differs.

These tests include:

• Computed tomography scan (CT scan) is generally the first diagnostic test done after a person suspected of having a stroke arrives in the emergency department. The test uses low-dose x-rays to take pictures of the inside of the brain.

  For more information about CT Scan, go to Computed tomography scan (CT scan).

• Magnetic resonance imaging (MRI) is an advanced diagnostic tool that uses the principals of magnetism to view the inner body. An MRI of the brain can show small blood vessels that may be blocked or bleeding.

  For more information about MRI, go to Magnetic resonance imaging (MRI).

• Transcranial doppler (TCD) is a new, noninvasive ultrasound procedure that uses a small probe placed against the skull to track the blood flow through the vessels in the brain.
• SPECT imaging uses low doses of a harmless radioactive substance injected into a vein in the arm, then uses a specialized camera to view the blood flow in the brain.

Medicines To Treat Stroke

If the stroke is caused by a blockage:

• Drug therapy is a relatively recent approach to the treatment of stroke. If the stroke is caused by a blockage in an artery, medications called thrombolytic drugs can be used. The only drugs approved by the FDA for treatment of stroke are tissue plasminogen activators (TPA drugs). Popularly referred to as “clot-busting” drugs, these medications have been used for years to treat heart attacks.

  Some studies have indicated that if TPA drugs are given to stroke patients within three hours of the onset of symptoms, more than half of them will make a full recovery in a matter of months.

  Not all hospitals, however, have the ability to give TPA drugs to people having a stroke. Before these drugs can be given, doctors must be certain that the stroke is the result of a blockage in the artery and not due to bleeding from an artery. This is determined through imaging procedures such as computed tomography (CT) scans and magnetic resonance imaging (MRI). But not all hospitals have around-the-clock imaging services.

If a stroke is caused by bleeding:

• Medication can be given to reduce swelling of brain tissue.

Surgical Procedures

If the stroke is caused by a blockage:

A procedure called carotid endarterectomy can be used to remove a buildup of plaque from inside the carotid artery, one of the major sources of blood to the head and neck. Carotid endarterectomy can be used to treat people who have had a stroke and also as a preventive measure for people at risk for stroke.

If the stroke is caused by bleeding:

• An artery within the brain sometimes can be “clipped” to prevent further bleeding.
• If the bleeding has occurred in the subarachnoid space, pooled blood (hematoma) can dangerously increase pressure on the brain and damage delicate tissue. If it is feasible, surgery may be necessary to drain blood from within the area of damaged brain tissue.

Other Procedures

Several types of interventional radiology also are available to treat stroke. These procedures have been in existence for some time, but they have been improved and refined in recent years. However, not all hospitals are equipped to offer interventional radiology.

Interventional radiology is performed by inserting a long, thin, flexible tube called a catheter into blood vessels. The insertion point is usually in the groin, and the incision is about the size of the tip of a pencil. The catheter is guided to various parts of the body while a computer tracks it and records images of the blood vessels. This procedure creates a precise road map of even the tiniest vessel in the body.

• The catheters can be guided to areas of bleeding and used to effectively close off the leaking vessels.
• The catheters can be used to widen areas of blood vessels that have become narrowed because of a buildup of plaque.
• The catheters can be used to place stents made of a fine, tubular wire mesh to hold a blood vessel open.

What To Expect During A Hospital Stay

After the initial tests to determine the type of stroke and the best treatment, other procedures may be necessary to find the cause of the stroke. These procedures may include tests of the heart or the arteries to the brain.

The length of the stay in the hospital and the type of treatment will depend on the severity of the stroke. Many people need some form of therapy to help their brain relearn skills lost because of the stroke.

Effects Of A Stroke

A stroke affects different people in different ways. While some people make a full recovery, others may find that some problems do persist. These may include:

• Speech changes
• Vision changes
• Memory and concentration difficulties
• Paralysis
• Weakness and stiffness
• Difficulty eating and swallowing
• Mood changes
• Difficulties with personal relationships
• Other challenges

Speech Changes

Some people have difficulty with speech. When stroke has damaged the part of the brain that controls the muscles used to produce speech, speech may become slurred. The survivor understands words and conversation but cannot speak distinctly. This condition is called dysarthria.

When stroke has damaged the part of the brain that controls language, the survivor may lose the ability to speak and understand speech. The ability to read and write can be affected. The person may have difficulty finding the right word or may use an incorrect word. He or she may find, when reading, that some words make no sense. This condition is called aphasia.

Vision Changes

Stroke may affect vision on one side (usually the same side that has been weakened by the stroke). When talking to someone with impaired vision, always stand or sit on the “good” side. Consider that the person may ignore people or objects on the other side and may bump into them.

Memory And Concentration Difficulties

Memory and concentration may be affected after a stroke. In the early stages, individuals may not be able to concentrate for very long and may become easily distracted. They may have problems with particular tasks, such as finding the way about the house or getting dressed, yet have no other major difficulties.

Paralysis

Stroke frequently causes paralysis on one side of the body. This condition is called hemiplegia. The paralysis may affect only the face, an arm, or a leg; or it may affect one entire side of the body and face.

• A person who suffers a stroke in the left side of the brain may show right-sided paralysis.
• A person who suffers a stroke in the right side of the brain may show paralysis on the left side of the body.

Weakness And Stiffness

Paralyzed limbs may recover their strength but may remain clumsy or stiff. Some types of muscular stiffness (a condition called spasticity) can be helped with medication. People with weak hands often are given a soft ball to squeeze to help improve their grip.

Difficulty Eating And Swallowing

Damage to certain areas of the brain can cause difficulty eating and swallowing. This condition is called dysphagia. Therapy to help the brain relearn these skills has shown great success. Until a person is able to eat again, he or she can receive sustenance intravenously (with an IV that delivers nourishment directly into the bloodstream). Most people who have had a stroke will recover their ability to swallow safely.

Mood Changes

The days and months after experiencing a stroke are a stressful time. The stroke survivor may be unable to return to work immediately and may lose independence for a while. After the immediate shock, a stroke survivor may feel anxiety, anger, and frustration. A lack of information may contribute to the anxiety. Anxiety and frustration can be reduced by support from doctors, therapists, and other caregivers.

Personal Relationships

Many people worry that sexual intercourse may bring on another stroke. This is not true. A person who has recovered from a stroke can return to all normal activities, including sexual relations. Even people who are still experiencing some difficulties related to a stroke can resume normal loving and intimate relationships.

Other Challenges To Face

Because a stroke affects each person differently, there may be other physical challenges:

• The sensitivity of the skin may be altered after a stroke. Some people experience numbness while others feel as if their skin is extra sensitive.
• Certain individuals experience pain, uncomfortable numbness, or strange sensations after a stroke. These sensations may be caused by many factors, including damage to the sensory regions of the brain.
• Control of bowels and bladder may be lost temporarily after a stroke, but most people do recover function.

Recovering From A Stroke

Many people begin to recover from a stroke almost immediately after it has occurred.

The recovery process is most rapid in the first three months after a stroke, but improvement will continue for six months or a year. Many stroke survivors report that they slowly continue to regain function for years after their brain attack. It is very important not to lose hope.

Everyone’s recovery is different, but some general rules hold true. Simple skills will be recovered first:

• The ability to sit up and balance while sitting, then
• The ability to stand, and then
• The ability to walk.
• The leg usually starts to improve before the hand.

Some people will notice that “things do not work so well” when they are tired or get a minor illness such as a cold. For example, a person’s speech may get more hesitant toward the end of a busy day, or the person may become more unsteady after the flu. These ups and downs are to be expected and are not a sign that another stroke is about to occur.

The Importance Of Rehabilitation Therapy

Successful recovery after a stroke depends on the extent of brain damage, the person’s attitude, the skill of the medical team, and the cooperation of family and friends. Not all people recover on their own. For them, rehabilitation therapy can be invaluable.

Rehabilitation can teach new skills to replace old skills that may have been lost. It involves teaching other areas of the brain to take over the work of the damaged portions.

One of the first rules of successful rehabilitation is that it must begin as soon after a stroke as possible. Therefore, it usually starts in the hospital and is continued as long as necessary after the person goes home. The goal of therapy is to improve function so that the person who has had a stroke can become as independent as possible.

Depending on the severity of the stroke, rehabilitation options include:

• A rehabilitation unit in the hospital
• A subacute care unit
• A rehabilitation hospital
• Home therapy
• Home with outpatient therapy
• A long-term care facility that provides therapy and skilled nursing care

Avoiding Another Stroke

Many survivors are afraid that they will have another brain attack. However, with proper medical treatment, it is quite unlikely that a person who has had a stroke will experience another. The risk of a second stroke is higher for people who are not receiving proper medical treatment for their first stroke.

Effective treatment to reduce the risk of another stroke includes making lifestyle changes to decrease risk factors and taking medication, such as aspirin, as directed by a doctor.

Preventing A Stroke

The best way to prevent stroke is to reduce your risk factors and take control of your own health:

• Lower your cholesterol level if it is elevated – some people can do this by modifying diet; others need to take medication. Lowering cholesterol levels has been proven by researchers to reduce the risk of stroke.

  For more detailed information on how to lower your cholesterol, go to Lowering Your Cholesterol.

• If you smoke, stop smoking – Many excellent smoking cessation programs are available today; your doctor can advise you about tools you can use, such as the nicotine patch.

  For more information about how to stop smoking, go to Smoking: How To Stop.

• Drink alcohol in moderation – A drink or two a day is considered acceptable.
• Keep your weight within normal limits.
• Get a moderate amount of exercise at least five days a week.
• Eat a healthy diet that is high in fruits and vegetables and low in fats.
• If you have cardiovascular disease, work with your doctor to treat it. Certain types of problems with the heart and blood vessels, such as atherosclerosis and atrial fibrillation can cause blood clots to form. These clots can block an artery in the brain and cause a stroke (or can block a blood vessel in the heart and cause a heart attack).
• If you have diabetes, keep it under good control.

  For more detailed information on how to control your diabetes, go to Diabetes.

• If you have high blood pressure be sure to take your medication regularly.

  For more detailed information on how to lower your blood pressure, go to Hypertension.

• Know the warning signs of TIAs and strokes, and get help right away if you experience them.

Medications For Prevention

Certain medications have been shown to reduce the risk of stroke. These drugs fall under two major categories. They aim to prevent the formation of dangerous blood clots:

• Antiplatelet agents such as aspirin – These drugs work by preventing or reducing platelet aggregation in the bloodstream. Platelets are tiny blood cells that cause blood to coagulate or clot. When a blood vessel is damaged or injured, platelets will migrate to the area to begin a healing process. However, large numbers of platelets can clump together or aggregate and form a clot that is essentially a plug in an artery. Antiplatelet agents help prevent this clumping.
• Anticoagulants – These drugs work by thinning the blood and preventing clotting. Common anticoagulants are heparin and warfarin.

Antiplatelet and anticoagulant drugs can also be used to treat heart disease, so taking one medicine can help reduce your risk of both heart attack and brain attack. Your doctor can advise you on what medications are right for you.

Surgery For Prevention

Carotid endarterectomy – the same procedure that can sometimes be used to treat strokes caused by a blockage – can also be used to help prevent such strokes from happening in the first place.

The procedure involves removing plaque buildup in the carotid artery . It is performed when the artery is blocked by more than 70 percent.

• It has been proven that for certain individuals who have had minor strokes or TIAs, and the carotid artery in the neck is more than 70 percent blocked (i.e. severely blocked), this procedure can reduce the risk of future strokes.
• It also is beneficial for individuals with blocked carotid arteries who have not had previous symptoms of stroke.

Carotid endarterectomy takes about an hour to perform. A tube is placed to transport blood around the area to be treated. After the surgeon has scraped away the built-up plaque, the artery is sewn back together and blood flow is restored.

Currently, carotid endarterectomy is available only at major treatment centers in the U.S. Among the risks is the possibility of experiencing a stroke during the procedure itself. If you are considering this procedure, you and your doctor should weigh the risks and benefits.

The Role Of Vitamin E

Research suggests that vitamin E helps prevent arteries from clogging by blocking the conversion of cholesterol into its most dangerous form. Vitamin E is also a powerful anti-clotting agent. It helps the blood flow more easily through arteries when fatty plaques are present. It also is an antioxidant, which means it helps prevent cell damage. Ask a doctor about the proper amount of this vitamin to take daily.

What Is The Long Term Outlook After A Stroke?

Today, the outlook for people who have had a brain attack is more hopeful than ever before. Because of advances in treatment and rehabilitation, many people can return to a fulfilling life.

A stroke survivor’s family plays a vital role in recovery. Family members need to understand what the person is going through, what to expect, and how to handle problems that will arise. A person’s will to recover and desire to be independent play a big part in recovery; the family can help by providing a warm, supportive, and encouraging atmosphere.

The understanding of what causes strokes and how best to treat them is still expanding. Researchers at the National Institute of Neurological Disorders and Stroke in Bethesda, Md., predict that Americans should be able to prevent 80 percent of all strokes within the next 10 years. They believe this will happen because of continued attention to reducing the risks of stroke and by using currently available therapies and developing new ones.

Among those new therapies are drugs that make the brain less susceptible to the damaging effects of a stroke. Called neuroprotective agents, these drugs include citicoline and lazaroid compounds. They currently are under evaluation in clinical trials.

Stroke: Frequently Asked Questions

Here are some frequently asked questions related to stroke.

Q: Can a stroke just happen out of the blue?

A: A stroke, which also is referred to as a “brain attack,” often does happen without any prior warning. However, the conditions that lead to a stroke have usually been present for many years. Maintaining the healthiest lifestyle possible, therefore, is very important in stroke prevention.

Q: My father suffered a stroke three months ago but insists he is capable of driving. Should I worry?

A: A stroke can affect eyesight, coordination, the movement and strength of arms and legs, balance, reaction time, concentration, speed of thought, memory, awareness of where objects are in relation to each other, and even the awareness that anything is wrong at all. A difficulty in any one of these areas carries with it the possibility of making driving unsafe. Your father’s doctor can provide the best advice on whether he should be driving.

Q: Ever since his stroke, my husband has been reluctant to have sex, even though he seems to have made a full recovery. Is this normal?

A: There are many myths about having sex after a heart attack or stroke. The most common one is that sexual activity will bring on another heart attack or stroke and cause sudden death. This simply isn’t true. There’s no reason why someone who has had a heart attack or stroke can’t resume usual sexual activity as soon as he or she feels ready to do so. For some men, fear about performance can greatly reduce sexual interest and ability to have an erection. An understanding partner, patience, and open discussion with a doctor or therapist are extremely helpful in resuming sexual intercourse.

Q: At what age should I seriously consider taking aspirin to help reduce my risk of having a stroke?

A: The need for aspirin therapy depends on individual risk factors and is different for everybody. Most health care providers suggest that after age 50, you and your doctor should make a decision about aspirin therapy. Some people benefit from taking aspirin before age 50.

Stroke: Putting It All Together

Here is a summary of the important facts and information related to stroke.

• A brain attack or stroke happens when a part of the brain is damaged by a change in blood flow. This change can happen if something blocks the flow of blood to the brain or if a blood vessel bursts and causes bleeding in the brain.
• In many cases, a stroke can happen without warning. But some people do experience “mini-strokes,” called TIAs, which are exactly like a stroke but last only a short time. A TIA, like a stroke, is considered a medical emergency and should never be ignored.
• The signs of stroke are sudden weakness or numbness on one side of the body, sudden loss of vision or speech, sudden severe headaches, or unexplained dizziness that comes on quickly.
• Some risk factors for stroke, such as age and race, cannot be changed. But there are steps you can take to reduce other risk factors, such as high blood pressure, high cholesterol, and cigarette smoking.
• If a brain attack does happen, medical treatments can be given in the hospital emergency department. These treatments have shown great success in minimizing damage to the brain. The key is to get medical help immediately. Too often, people having a stroke wait for hours before seeking help.
• A stroke can cause trouble speaking or seeing, memory difficulties, paralysis or weakness, difficulty eating, and mood changes. The good news is that therapies are available to help teach the brain skills it might have lost. Many people can make a full recovery and resume a fulfilling life after a stroke.
• The best way to prevent stroke is to reduce risk factors – improve diet, keep diabetes under control, quit smoking, and get enough exercise. Medication is also available to help prevent stroke. The most frequently used preventive medication is aspirin, which helps prevent blood clots.
• The long-term outlook for people who have had a stroke is more hopeful than ever before. Because of advances in treatment, more people are surviving strokes, and because of advances in rehabilitation, more people are conquering the disabilities that can be caused by a stroke.

Stroke: Glossary

Here are definitions of medical terms related to stroke.

Aneurysm: An abnormal, balloon-like bulging of the wall of an artery. The bursting of an aneurysm in a brain artery or blood vessel causes a hemorrhagic stroke.

Anticoagulant agents: Drugs used to prevent blood clots from forming or growing. They work by interfering with the production of blood components that are necessary for clot formation.

Antiplatelet agents: Drugs used to prevent blood clots from forming or growing. Antiplatelet agents slow production of an enzyme that causes platelets to stick together.

Aphasia: A term for communication problems that may include the loss or reduction of the ability to speak, read, write, or understand. Aphasia is caused by damage to the parts of the brain that control language.

Artery: A blood vessel that carries blood away from the heart and around the body.

Atherosclerosis: A buildup of cholesterol plaque and other fatty deposits in the arteries. It can put people at higher risk for stroke, because clots can become stuck in narrowed arteries within the brain, cutting off blood flow.

Atrial fibrillation: A condition in which the heartbeat is often irregular and unusually rapid. It can put people at higher risk for stroke, because the condition causes blood clots to form, and these clots can travel to the brain and block a blood vessel.

Cardiovascular disease: Any abnormal condition caused by problems with the heart and blood vessels.

Carotid artery: The arteries on each side of the neck that carry blood from the heart to the brain.

Carotid endarterectomy: The surgical removal of plaque that is blocking or reducing blood flow in a carotid artery.

Cerebral infarction: A stroke caused by interruption or blockage of blood flow to the brain; also called ischemic stroke.

Cerebrovascular disease: The term used to describe all abnormalities of the brain caused by problems with its blood vessels. Stroke is the major, but not the only, form of cerebrovascular disease.

Dysarthria: Slurred speech caused by damage to the parts of the brain that control the muscles used in speech production.

Dysphagia: An inability to swallow and/or difficulty in swallowing.

Hemiplegia: Paralysis on one side of the body.

Intracerebral hemorrhage: A stroke caused by a ruptured blood vessel that causes bleeding in brain tissue.

Ischemic stroke: A stroke caused by interruption or blockage of blood flow to the brain; also called cerebral infarction.

Plaque: Fatty deposits that stick to the inside walls of blood vessels, causing the vessel to become narrow and, in some cases, blocked altogether.

Platelets: Tiny blood cells that stick together to stop the flow of blood around a wound to a blood vessel.

Spasticity: Abnormal tightness or stiffness in a muscle.

Stroke: A type of cerebrovascular disease that is caused by a sudden interruption of blood flow to a part of the brain, which can kill or damage brain cells. A brain attack.

Subarachnoid hemorrhage: A stroke caused by a ruptured blood vessel that bleeds into the subarachnoid space between the brain and the skull. This space between the web-like arachnoid membrane and the surface of the brain is filled with cerebrospinal fluid. It acts as a cushion to protect the brain from blows.

Thrombolytic agents: Drugs that break up or dissolve clots that can cause a stroke or heart attack.

Tissue plasminogen activators (TPAs): The only FDA-approved treatment for stroke.

Transient ischemic attack (TIA): A temporary interruption of the blood supply to an area of the brain; sometimes called a “mini-stroke,” it usually lasts only a few minutes and causes no permanent damage or disability.

Stroke: Additional Sources Of Information

Here are some reliable sources that can provide more information on stroke.

National Institute of Neurological Disorders and Stroke (NINDS) 
http://www.ninds.nih.gov/

National Stroke Association 
Phone: 303-649-9299
Phone: 1-800-STROKES (787-6537)
http://www.stroke.org/

Find links to products and services for stroke survivors and caregivers, self-screening techniques to detect a heart condition called atrial fibrillation (which is a leading stroke risk factor), and a quiz you can take to assess your risk. Click on the “Test Your Stroke IQ” link.

American Stroke Association A Division of American Heart Association 
Phone: 1-888-4STROKE (478-7653)
Email: strokeassociation@heart.org 
http://www.strokeassociation.org/

Heart and Stroke Foundation of Canada 
Phone: 1-613-569-4361
Email: itstaff@hsf.ca 
http://ww1.heartandstroke.ca/