Stroke | Description | Prevention | Causes and symptoms | Treatment
Definition
Brain cells need oxygen and nutrients to function properly. When blood flow to the brain is interrupted, brain cells can begin to die and a person can experience a stroke, also called a brain attack. Damage from a stroke can temporarily or permanently disable a person's movement, speech, and cognition.
Description
A stroke occurs when blood flow to the brain is blocked or stopped. Strokes generally fall into two categories: strokes that occur when blood flow is blocked and strokes that occur because of bleeding in the brain.
Ischemic strokes are the most common cause of stroke and occur when a blood vessel in the brain or neck becomes blocked. Ischemic strokes comprise 87 percent of all strokes, and are not generally fatal.
Three conditions may contribute to the ischemia , or blockage.
Thrombosis: When a blood clot forms in a blood vessel in the brain or neck. Embolism: When a clot moves from another part of the body to the brain or neck. Stenosis: When an artery in or leading to the brain becomes severely narrowed and impedes blood flow.
Prior to an ischemic stroke, a person may experience mini strokes, also known as transient ischemic attacks (TIA). These strokes have symptoms similar to those of a stroke, but the symptoms are temporary and disappear. For most people, TIAs do not precede a stroke, but among people who have had one or more TIAs, more than a third will later have a stroke.
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Percentage of people in the United States age 65 and over who reported having a stroke, by sex and by race, 2005–2006 |
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Sex |
Percent |
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Data is based on a 2-year average from 2005–2006. |
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source: National Health Interview Survey, National Center for |
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(Illustration by GGS Information Services. Cengage Learning, |
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Men |
10.4% |
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Women |
8.4% |
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Total |
9.3% |
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Race |
Percent |
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White |
8.9% |
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Black |
15.6% |
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Hispanic or Latino |
6.5% |
Strokes that occur because of bleeding in the brain are called hemorrhagic strokes. Intracerebral hemorrhages comprise 10 percent of all strokes. This type of hemorrhagic stroke occurs when a diseased blood vessel inside the brain bursts and blood begins leaking inside the brain. Subarachnoid hemorrhages, which occur when a blood vessel outside the brain ruptures and causes the skull surrounding the brain to fill with blood, comprise 3 percent of all strokes.
Treating and rehabilitating stroke victims poses an enormous cost to the U.S. health care system. It is estimated that in 2008, the direct and indirect costs of stroke will reach $65.5 billion.
Demographics
Stroke ranks as the third leading killer in the United States, behind heart disease and cancer . According to the American Stroke Association, one out of every 16 deaths in 2004 was attributable to stroke. Stroke also leads the list of causes of serious, long-term disability in the United States.
New strokes are more common than recurrent strokes. About 780,000 people experience strokes annually, about 600,000 of which are new strokes and 180,000 of which are recurrent strokes.
Among people ages 55 to 74, men have a slightly higher risk of stroke than women. In people ages 75 to 84, men and women have a similar risk of stroke. In people 85 and older, men are less likely to have a stroke than women. Also, more women die of stroke every year, in part because as a group, women live longer than men. Sixty-one percent of U.S. stroke deaths occur in women.
Stroke incidence also varies depending on racial/ethnic group. Compared to whites, blacks have almost twice the risk of having a first-time stroke and they have a greater risk of death due to stroke. Mexican Americans also have an increased incidence of stroke overall, compared to whites, and an increased risk of having a stroke at a younger age.
In the United States, stroke risk and mortality rates may also be tied to geographic region. Researchers have found that people living in the “Stroke Belt,” a region in the southwestern part of the United States that includes Alabama, Arkansas, Georgia, Indiana, Kentucky, Louisiana, Mississippi, North Carolina, South Carolina, Tennessee, and Virginia, had stroke death rates more than 10 percent higher than the U.S. average. Men and women in both black and white ethnic groups living in the Stroke Belt had higher stroke death rates than their counterparts in other regions of the country.
Causes and symptoms
Several untreatable and treatable risk factors exist that increase a person's risk of having a stroke.
Risk factors for stroke that cannot be changed include:
· Age: According to the American Stroke Association, the risk of having a stroke doubles for each decade of life after age 55.
· Gender: Overall men have a greater risk of stroke, but women have a greater risk of death due to stroke.
· Family history and ethnicity: If a close relative (parent, grandparent, or sibling) has had a stroke, a person has a greater risk of having one, too. In addition, blacks have a greater stroke risk than whites.
· Having had stroke warning signs or a previous stroke.
The good news for many older adults is that the stroke risk factors that follow can be reduced by making some changes to lifestyle, exercise habits, and nutrition.
· High blood pressure, also called hypertension, is one of the main factors that puts a person at risk for stroke.
· Smoking: Dependence on cigarettes damages the cardiovascular system and increases the risk of stroke. The risk of ischemic stroke in smokers is double that of nonsmokers.
· Heart disease: People with atherosclerosis, or fatty deposit buildup on the walls of the arteries, are prone to having narrowed arteries that may become blocked by blood clots. Older adults with heart defects or heart failure also have an increased risk of stroke.
· Atrial fibrillation: This problem with the heart's rhythm raises the risk of blood clots and increases a person's risk of stroke five-fold.
· Taking estrogen plus progestin during menopause: A large clinical trial in women found that taking estrogen plus progestin increased ischemic stroke risk by 44 percent.
· Diabetes: Having diabetes on its own increases a person's risk for stroke, but having high cholesterol, high blood pressure, and being overweight, conditions that often go hand in hand with diabetes, send stroke risk percentages spiraling higher.
· High cholesterol: Having high cholesterol levels increases the risk for stroke.
· Depression: In people under age 65, risk of stroke was more than 5 times higher in people with depressive symptoms.
· Poor diet and physical inactivity: High-fat, high-sodium, high-cholesterol diets and lack of exercise contribute to numerous medical problems and increase the risk of stroke.
· Alcohol and drug abuse: Abusing these substances also increases a person's risk for a stroke.
Stroke symptoms often occur suddenly and without warning. Older adults who experience stroke symptoms or their caregivers should call 911 or go to a hospital emergency department immediately.
Symptoms of stroke, or loss of oxygen and blood flow to the brain, include sudden:
· weakness or numbness in the leg, arm, or face, especially on one side of the body
· confusion or difficulty speaking or understanding
· vision problems in one or both eyes
· dizziness, problems walking, or loss of balance
· severe headache that comes on suddenly and doesn't have another cause
· drowsiness
· nausea or vomiting
In many cases, these warning signs of a stroke occur suddenly and then disappear. If these symptoms go away quickly, they are easy to ignore, but that early resolution does not mean they are not dangerous.
Diagnosis
When making a stroke diagnosis, health care professionals first obtain a complete medical history. A person with stroke symptoms (or a family member or caregiver , if the person cannot communicate) will be asked about his current and previous symptoms, medical problems or surgeries he has had previously, and medications he is taking. A person having stroke symptoms will also be examined and health care professionals will check his reflexes, strength, sensation, and overall coordination. Questions may also be asked to determine whether the patient's memory, speech, or cognition is impaired.
Laboratory tests and procedures may also be helpful when making a stroke diagnosis. To look at the brain, skull, or spinal cord, health care professionals may use computed tomography (CT) scans or magnetic resonance imaging (MRI) scans. Getting a view of the blood vessels that supply the brain may be accomplished by using ultrasound waves to take a picture of the carotid arteries in the neck (this is called a carotid ultrasound or carotid Doppler). Transcranial Doppler or magnetic resonance angiogram may also be used to see the blood vessels in the neck or brain. Another test, called a cerebral arteriogram, uses a catheter inserted in the arm or leg to find any abnormalities of the blood vessels, such as blockages or narrowing.
Other tests, including echocardiograms and electrocardiograms (EKG), may be used to check the heart's function. X-rays, urine samples, and blood oxygen tests may be used to check for infection, and neurologic tests, such as electroencephalogram or nerve conduction tests, may be done if a health care professional suspects a seizure or nerve problem is causing symptoms. Lumbar puncture (LP or spinal tap), the removal of fluid that surrounds the brain and spinal cord, may be used to check for bleeding from a subarachnoid hemorrhage. If doctors think a person has had a stroke, they also usually order blood tests to measure chemicals in the blood, check cholesterol levels, and identify clotting problems that may contribute to stroke.
Treatment
If a person has been diagnosed with a stroke, there are many steps on the road to recovery.
The first stage involves acute care treatment. During this type of treatment, health care professionals work to help the patient survive and prevent another stroke.
People who have had strokes may need to take antiplatelet drugs (such as aspirin , clopidogrel, ticlopidine, and aspirin/dipyridamole) to prevent blood clotting and reduce the risk of recurrent thrombotic stroke. Others may need to take anticoagulants (such as warfarin and heparin) to prevent clot formation.
Sometimes thrombolytic agents are used to treat an ongoing ischemic stroke. If a person having a stroke gets medical treatment within 3 hours of stroke onset, thrombolytic drugs such as recombinant tissue plasminogen activator (rt-PA) can be used to dissolve the blood clot that is blocking blood flow to the brain. Because these drugs can increase bleeding, they should only be used by a doctor who has carefully examined a suspected stroke patient.
Surgical procedures such as carotid endarterectomy may also be performed to reduce the risk of acute or recurrent stroke. In this procedure, surgeons open the carotid artery in the neck and scrape plaque from the artery's walls, thereby reducing the chance that blood clots might lodge in the narrowed artery and cause a stroke.
Devices can also be inserted in the carotid artery to reduce stroke risk. In a procedure called an angioplasty , a small tube called a stent is placed over the artery to help keep it open and reduce the risk of blockage that could cause a stroke. Stents are usually used in people who have had TIAs or who have at least half of their arteries blocked. People who have 80 percent blockage but who have never experienced a stroke might also be advised to have a stent placed.
Stroke treatment also involves recovery and rehabilitation. After acute care, some of the abilities a person has may begin to come back, which is called spontaneous recovery. Spontaneous recovery occurs in the days, weeks, and months following the stroke. Rehabilitation involves helping someone who has had a stroke recover some of the abilities that were lost. Rehabilitation can take place in the hospital, at a recovery facility, or at the patient's home.
Nutrition/Dietetic concerns
Eating a diet that contains too much fat, cholesterol, and sodium (salt) can increase stroke risk. Health care professionals recommend that person who has had a stroke or has stroke risk factors should reduce stroke risk by taking the following steps.
Consume foods lower in fat. Eating a diet filled with saturated fat and cholesterol contributes to atherosclerosis , a factor that increases the risk of stroke. Older adults can cut the fat by choosing low-fat or nonfat dairy items, limiting oil or butter used in cooking, avoiding fried foods in favor of broiled or baked versions, and trimming fat or skin from meats and poultry.
Watch sodium intake. Eating too many high-sodium foods (sodium, or salt, is often used to preserve foods and add flavor) can increase blood pressure and thereby increase the risk of stroke. To cut back on sodium, instead of highly processed foods, choose fresh fruits, vegetables, whole grains, and lean sources of protein. Also, some evidence suggests that adding fiber to the diet might help reduce cholesterol levels. High cholesterol levels are another risk factor for stroke.
Limit alcohol consumption. Research has shown that drinking up to two drinks a day can cut stroke risk in half, but drinking too much does more harm than good. Consuming more than two drinks a day increases stroke risk three-fold. Also, alcohol interacts dangerously with many medicines, so people taking medication should talk to their doctors before consuming any amount of alcohol.
Therapy
Older adults who have experienced a stroke may require a variety of therapies during the rehabilitative process.
Physical therapy, which the National Institute of Neurological Disorders and Stroke calls the “cornerstone of the rehabilitative process,” helps people with stroke relearn balance, movement, and coordination. This type of therapy is essential to help stroke victims learn to walk, sit, stand, and lie down, movements that may be difficult after experiencing a stroke.
Occupational therapy is also often used in post-stroke recovery. With this type of therapy, people who have experienced a stroke relearn how to do activities of daily living, such as eating and drinking, cooking, writing, toileting, and bathing.
For stroke victims who experience speech and language problems, speech therapy can help them understand speech and written words, form words themselves, and develop alternative ways of communicating.
Depression , anxiety , and frustration are a common aspect of the stroke survivor's experience, and psychological counseling can help survivors deal with these problems. Sometimes, cognitive behavioral therapy or medication might be recommended for the survivor to alleviate post-stroke psychiatric problems.
QUESTIONS TO ASK YOUR DOCTOR
· Do I have any of the risk factors for stroke, such as high cholesterol or high blood pressure?
· If I experience any of the warning signs of stroke, what should I do?
· Is there anything I can do now to reduce my risk of stroke?
· I've had TIAs. What can I expect in terms of stroke risk?
· I've survived a stroke. What can I do to improve my recovery and regain function?
· I'm caring for someone who's had a stroke. Can you recommend a support group for me?
Prognosis
People who experience one stroke often go on to have others. According to the National Stroke Association, of the people who have a stroke every year, 5 to 14 percent will have an additional stroke within 1 year. Within 5 years after an initial stroke, 24 percent of women and 42 percent of men will experience recurrent stroke.
In people between 45 and 64, 8 to 12 percent of ischemic strokes and 37 to 38 percent of hemorrhagic strokes cause death within a month.
Prevention
Lowering stroke risk often involves making lifestyle changes, such as sticking to a low-sodium, low-fat diet , to improve circulation and reduce the risk of diseases that can influence stroke risk, such as diabetes, heart disease, high cholesterol, and high blood pressure.
Exercise, especially moderate to high intensity exercise, has also been associated with a lowered risk of stroke. In a large Japanese study of 73,265 men and women, risk of stroke death dropped 29 percent in men and 20 percent in women who got the most intense exercise.
Some older adults might also need to take medication to lower blood pressure and cholesterol, two leading risk factors for stroke. Other adults who are diabetic need to follow their diabetes care plan and control their blood sugar levels carefully, through diet, exercise, and medications.
KEY TERMS
Carotid endarterectomy —Procedure to open the carotid artery in the neck and scrape plaque from the artery's walls, thereby reducing the risk of stroke.
Hemorrhage —Bleeding from the blood vessels.
Ischemia —Blockage of blood flow due to obstruction of the blood vessels.
Stent —A small tube placed within an artery to help keep it open and reduce the risk of blockage that could cause a stroke
Transient ischemic attack (TIA) —Mini strokes that cause symptoms similar to those of a stroke, but which are temporary and disappear.
Caregiver concerns
Caregivers of people who have experienced a stroke will initially want to familiarize themselves with the physical, emotional, and cognitive changes that might occur in the post-stroke recovery period.Stroke victims may experience memory loss , confused behavior or poor judgment, depression, unpredictable or inappropriate emotions (a condition sometimes called involuntary emotional expression disorder), communication problems, problems dressing and grooming themselves and caring for their skin, problems eating, and pain .
To help prevent confusion in the stroke survivor, a caregiver needs to ensure that the survivor's environment is orderly and easy to navigate. If the stroke victim is having trouble dressing or feeding himself or herself, talk to the person's health care provider or stroke rehabilitation specialist about adaptive aids that may make independent living easier.
To deal with the emotional changes and depressive symptoms that often accompany the post-stroke recovery period, stroke victims might need behavioral therapy, antidepressant medications, or a combination of both.
Communication problems or difficulty with speech (referred to as aphasia) often occur after stroke because of damage to the areas of the brain that control communication. Caregivers might need to secure professional help to cope with these difficulties.
When caring for someone with a stroke, proper skin care is important, especially for survivors who spend lots of time sitting or in wheelchairs. Caregivers can help prevent bed sores by making sure the person changes position frequently and has pillows or other soft props to support disabled limbs.
Caring for a person who has had a stroke can be frightening, confusing, and frustrating for family members. To get emotional support in the post-stroke journey, caregivers can attend support groups for stroke victims and their families.
organizations
American Heart Association/American Stroke Association, 7272 Greenville Avenue, Dallas, TX, 75231, 800-AHA-USA-1 (242-8721), http://www.americanheart.org; http://www.strokeassociation.org.
National Institute of Neurological Disorders and Stroke, P. O. Box 5801, Bethesda, MD, 20824, 301-496-5751, 800-352-9424, braininfo@ninds.nih.gov, http://www.ninds.nih.gov.
National Stroke Association, 9707 E. Easter Lane Building B, Centennial, CO, 80112, 800-787-6537, 303-649 1328, info@stroke.org, http://www.stroke.org.
Rehabilitation Institute of Chicago, 345 E. Superior Street, First Floor, Chicago, IL, 60611, 312-238-5433, 312-238-2860, lifecenter@ric.org, http://lifecenter.ric.org.
Stroke Association UK, Stroke House, 240 City Road, London, United Kingdom, EC1V 2PR, 020 7566 0300, info@stroke.org.uk, http://www.stroke.org.uk.
Amy Sutton
