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StrokeHighlightsStatin Drug Approved for Stroke Prevention
Drug Warnings
Aspirin
Diagnosis Magnetic resonance imaging (MRI) is better than computed tomography (CT) in detecting whether stroke (especially ischemic stroke) has occurred, indicates an important Lancet study. Surgery Carotid endarterectomy appears to be superior to and safer than carotid angioplasty and stenting (CAS) for most patients with artery stenosis (narrowing) of over 60%, suggest several recent studies. Most experts recommend CAS only for patients who have severe stenosis (greater than 70%) and high surgical risk. Rehabilitation Constraint-induced movement therapy (CIMT) may help patients who have recently had a stroke regain use of a paralyzed arm. The technique involves repetitive motion exercises while restraining the less functional arm. IntroductionBlood Flow Blockage. The brain receives about 25% of the body's oxygen, but it cannot store it. Brain cells require a constant supply of oxygen to stay healthy and function properly. Therefore, blood needs to be supplied continuously to the brain through two main arterial systems:
![]() The Circle of Willis is the joining area of several arteries at the bottom (inferior) side of the brain. At the Circle of Willis, the internal carotid arteries branch into smaller arteries that supply oxygenated blood to over 80% of the cerebrum. A reduction of, or disruption in, blood flow to the brain is the primary cause of a stroke. Blockage for even a short period of time can be disastrous and cause brain damage or even death. A stroke is usually defined as two types:
The consequences of a stroke, the type of functions affected, and the severity, depend on where in the brain it has occurred and the extent of the damage. Ischemic StrokeIschemic strokes are by far the more common type, causing over 80% of all strokes. Ischemia means the deficiency of oxygen in vital tissues. Ischemic strokes are caused by blood clots that are usually one of three types:
Thrombotic or Large-Artery Stroke and Atherosclerosis. The thrombotic stroke accounts for about 60% of all strokes. It usually occurs when an artery to the brain is blocked by a thrombus (blood clot) that forms as the result of atherosclerosis (commonly known as hardening of the arteries). These strokes are also sometimes referred to as large-artery strokes. The process leading to thrombotic stroke is complex and occurs over time:
As these processes continue, blood flow slows. In addition, other events contribute to the coming stroke:
Embolic Strokes and Atrial Fibrillation. An embolic stroke is usually caused by a dislodged blood clot that has traveled through the blood vessels (an embolus) until it becomes wedged in an artery. Embolic strokes account for about 25% of all strokes and may be due to various conditions:
Lacunar Strokes. Lacunar infarcts are a series of very tiny, ischemic strokes, which cause clumsiness, weakness, and emotional variability. They are actually a subtype of thrombotic stroke and constitute about 38% of this major group. In some populations, such as among Japanese, they are the most common stroke subtypes. They can also sometimes serve as warning signs for a major stroke. Silent Brain Infarctions. Many elderly people have silent brain infarctions, small strokes that cause no apparent symptoms. They are detected in between 10 - 38% of elderly patients who undergo imaging tests for problems other than stroke. A 2002 study suggested that they double the risk for future stroke. They also may be major contributors to mental impairment in the elderly. Smokers and people with hypertension are at particular risk. Transient Ischemic Attacks (TIAs)Transient ischemic attacks (TIAs) are mini-ischemic strokes, usually caused by tiny emboli (clots often formed of pieces of calcium and fatty plaque) that lodge in an artery to the brain. They typically break up quickly and dissolve but they do temporarily block the supply of blood to the brain. The mental or physical disturbances resulting from TIAs generally clear up in less than a day, with nearly all symptoms resolving in less than an hour. However, experts now advise that a TIA should be taken very seriously and treated as aggressively as a stroke. Both stroke and TIA increase the risk for a subsequent stroke. Moreover, the risk for having another stroke can be as high as 40% within 5 years. The American Heart Association/American Stroke Association recommends these guidelines to prevent a second stroke after TIA: Lifestyle changes.
Drug treatments.
Surgery.
Hemorrhagic StrokeOver 15% of strokes occur from hemorrhage (sudden bleeding) in the brain. In a healthy brain, brain cells called neurons are protected from exposure to blood by the blood-brain barrier, a wall of tiny vessels and structural cells. In a hemorrhagic stroke, however, this barrier is broken. Hemorrhagic strokes may be categorized by how and where they occur.
SymptomsPeople at risk and partners or caretakers of people at risk for stroke should be aware of the general symptoms. The stroke victim should get to the hospital as soon as possible after these warning signs appear. It is particularly important for people with migraines or frequent severe headaches to understand how to distinguish between their usual headaches and symptoms of stroke. The American Stroke Association lists the following five warning signs of stroke. PEOPLE SHOULD IMMEDIATELY CALL FOR EMERGENCY ASSISTANCE IF THEY EXPERIENCE ANY OF THESE SYMPTOMS:
Research indicates that patients receive faster treatment for stroke if they arrive by ambulance rather than coming to the emergency room on their own. An easy way to remember the signs of stroke, and what to do, is by the acronym "F.A.S.T." If you think you or someone else is having a stroke, the National Stroke Association's F.A.S.T. test advises:
Symptoms of TIAs and Early Ischemic StrokeThe symptoms of a transient ischemic attack (TIA) and early ischemic stroke are similar. In the case of a TIA, however, the symptoms should resolve within 24 hours. Symptoms depend on where the injury in the brain occurs. The origin of the stroke is usually either the carotid or basilar arteries. ![]() The build-up of plaque in the internal carotid artery may lead to narrowing and irregularity of the artery's lumen, preventing proper blood flow to the brain. More commonly, as the narrowing worsens, pieces of plaque in the internal carotid artery can break free, travel to the brain, and block blood vessels that supply blood to the brain. This leads to stroke, with possible paralysis or other deficits. Symptoms From Blockage in the Carotid Arteries. The carotid arteries stem off of the aorta (the primary artery leading from the heart) and lead up through the neck around the windpipe and on into the brain. When TIAs or stroke occur from blockage in the carotid artery, which they often do, symptoms may occur in either the retina of the eye or the cerebral hemisphere (the large top part of the brain). Symptoms include the following:
Symptoms From Blockage in the Basilar Artery. The other major site of trouble, the basilar artery, is formed at the base of the skull from the vertebral arteries, which run up along the spine and join at the back of the head. When stroke or TIAs occur here, both hemispheres of the brain may be affected so that symptoms occur on both sides of the body. The following symptoms may develop:
Such strokes usually occur in the brain stem, which can have profound affects on breathing, blood pressure, heart rate, and other vital functions, but does not affect thinking or language. Speed of Symptom Onset. The speed of symptom onset of a major ischemic stroke may indicate its source:
Symptoms of Hemorrhagic StrokeCerebral Hemorrhage Symptoms. Symptoms of a cerebral, or parenchymal, hemorrhage typically begin very suddenly and evolve over several hours and include:
Subarachnoid Hemorrhage. When the hemorrhage is a subarachnoid type, warning signs may occur from the leaky blood vessel a few days to a month before the aneurysm fully develops and ruptures. Warning signs may include:
When the aneurysm ruptures, the stroke victim may experience:
Risk FactorsNew or recurrent strokes affect about 700,000 Americans every year. Although incidence of stroke has increased, more people are surviving stroke, and the death rate is declining. While age is the major risk factor, people with stroke are likely to have more than one risk factor. AgeOlder Adults. People most at risk for stroke are older adults, particularly those with high blood pressure, who are sedentary, overweight, smoke, or have diabetes. Older age is also linked with higher rates of post-stroke dementia. Younger Adults. Younger people are not immune, however. About 28% of stroke victims are under age 65. GenderIn most age groups except older adults, stroke is more common in men than in women. However, it kills more women than men, regardless of ethnic groups. It is not clear why women have a higher mortality rate from stroke. The arteries that lead to the brain may be more vulnerable to the effects of plaque build-up in women than in men. In 2007, the American Heart Association released new heart disease prevention guidelines for women. The new guidelines recommend daily aspirin therapy (75 - 325 mg/day) to help prevent stroke in high-risk women over the age of 65. For older women with a lower stroke risk, the AHA recommends 81 mg of aspirin a day or 100 mg of aspirin every other day. Aspirin does not appear to provide much stroke protection benefit for women under the age of 65. EthnicityAll minority groups, including Native Americans, Hispanics, and African-Americans, face a significantly higher risk for stroke and stroke death than Caucasians. The risk is also higher in Asian Americans, although stroke rates appear to be declining in this group. The differences in risk among all groups diminish as people age. The greatest disparity in risk occurs in young adults. Younger African-Americans are two to three times more likely to experience a stroke than their Caucasian peers and four times more likely to die from one. They also face a higher risk for death from heart disease. African-Americans have a higher prevalence of diabetes and hypertension than other groups. However, studies suggest that socioeconomic factors also affect these differences. GeographyPeople in the southeastern U.S. have had the highest risk for stroke in the country for some years; those at particular risk live in North Carolina, South Carolina, and Georgia. This risk may be shifting westward. High stroke rates are also occurring in the lower Mississippi valley and in Southern California. Socioeconomic differences do not fully explain these higher-risk areas. Heart Disease and Heart AttackHeart disease and stroke are closely tied for many reasons:
Abnormal Blood PressureHigh Blood Pressure (Hypertension). High blood pressure (known medically as hypertension ) contributes to 70% of all strokes. Researchers have estimated that controlling blood pressure can prevent nearly 40% of strokes. Two numbers are used to describe blood pressure phases and may affect stroke risk separately:
![]() Hypertension is a disorder characterized by chronically high blood pressure. It must be monitored, treated, and controlled by medication, lifestyle changes, or a combination of both. Heart Abnormalities Causing Traveling Blood Clots (Embolisms)Atrial Fibrillation. About one in six strokes are due to atrial fibrillation. This is a heart rhythm disorder in which the atria (the upper chambers in the heart) beat very quickly and nonrhythmically. The blood pools instead of being pumped out, increasing the risk for formation of blood clots that break loose and travel toward the brain. Atrial fibrillation poses a six-fold increased risk for stroke and may also pose a higher risk for complications after a stroke. Atrial fibrillation is uncommon in people under 60 years old, but about 6% of adults over age 80 have this heart rhythm disorder. In this patient group, the risk for stroke may be higher or lower with the presence of other risk factors, including having heart failure, high blood pressure, diabetes, and a previous history of stroke, TIA, or rheumatic heart disease. More women than men have AF, but risk for stroke is higher in women with this condition than in men. Patent Foramen Ovale. Patent foramen ovale (PFO) is a flap-like opening between chambers of the heart. The foramen ovale is always open during fetal development to enhance blood flow to the fetus. It then typically closes after birth when the lungs take over. However, evidence suggests that it remains open in up to 30% of adults. In such cases, blood moves backward (right to left) through this opening when pressure in the right chamber exceeds the left. Large PFOs are a major cause of stroke, particularly in younger adults. Treatments include anti-clotting drugs and procedures for closing the opening. Atrial Septal Aneurysm. Atrial septal aneurysm is an inborn condition in which part of the atrium (one of the heart chambers) bulges out. Studies indicate that this may pose a slight risk for stroke in young people. SmokingPeople who smoke a pack a day have almost two and a half times the risk for stroke as nonsmokers. Smoking increases both hemorrhagic and ischemic stroke risk. The risk for stroke may remain elevated for as long as 14 years after quitting, so the earlier one quits the better. Diabetes and Insulin ResistanceHeart disease and stroke are the leading causes of death in people with diabetes. Diabetes is a strong risk factor for ischemic stroke, perhaps because of accompanying risk factors, such as obesity and high blood pressure. Diabetes does not appear to increase the risk for hemorrhagic stroke. Diabetes is second only to high blood pressure as the main risk factor for stroke. The risk is highest for adults newly diagnosed with type 2 diabetes and patients with diabetes who are younger than age 55. African-Americans with diabetes are at even higher risk for stroke at a younger age. Studies have also implicated insulin resistance, an important disease mechanism in type 2 diabetes, as an independent factor in the development of atherosclerosis and stroke. With this condition, insulin levels are normal to high, but the body is unable to use the insulin normally to metabolize blood sugar. The body compensates by raising the level of insulin, which in turn increases the risk for blood clots and reduces HDL levels (the beneficial form of cholesterol). Some studies have also reported a worse outcome in patients whose blood sugar levels are high at the time of a stroke. Obesity and Metabolic SyndromeObesity may increase the risk for both ischemic and hemorrhagic stroke independently of other risk factors that often co-exist with excess weight, including insulin resistance and diabetes, high blood pressure, and unhealthy cholesterol level. Weight that is centered around the abdomen (the so-called apple shape) has a particularly high association with stroke, as it does for heart disease, in comparison to weight distributed around hips (pear-shape). Obesity is particularly hazardous when it is one of the components of metabolic syndrome. This syndrome is diagnosed when three of the following conditions are present: abdominal obesity, low HDL cholesterol, high triglyceride levels, high blood pressure, and insulin resistance. Because metabolic syndrome is a pre-diabetic condition that is significantly associated with heart disease, people with this syndrome are at increased risk for stroke even before diabetes develops. Cholesterol and Other LipidsAlthough an unhealthy balance of cholesterol and other lipids (fatty compounds) plays a major role in heart disease, its role in stroke is less clear. Different lipids may have different effects: Ischemic Stroke. The effects of high total cholesterol and LDL levels on stroke are not clear. One study suggested that the risk for ischemic stroke increases when total cholesterol is above 280 mg/dL. HDL (the so-called good cholesterol) may protect against ischemic stroke (although statins have little effect on HDL). Hemorrhagic Stroke. HDL may reduce the risk for hemorrhagic stroke (bleeding in the brain). People with overall cholesterol levels below 180 mg/dL, however, may be at risk for hemorrhagic stroke, particularly if they also have high blood pressure. This is a far less common stroke, however, than ischemic stroke. In any case, reducing cholesterol is extremely important in anyone with heart disease and abnormal lipid levels. Genetic and Inborn FactorsGenetics may be responsible for many of the causes of stroke. Studies indicate that a family history of stroke, particularly in one's father, is a strong risk factor for stroke. Genetics and Subarachnoid Hemorrhage. Genetic factors account for between 7 - 20% of cases of subarachnoid hemorrhage. Ruptured aneurysms that occur in such patients tend to happen at an earlier age, are usually smaller, and are more apt to recur than in those without an inherited condition. A study of people who had suffered subarachnoid hemorrhages found that first-degree relatives of these stroke victims had a high lifetime risk of between 2 - 5%. Some experts recommend screening for aneurysms in people with more than one close relative who suffered a hemorrhagic stroke. Inherited Disorders that Contribute to Stroke. Some cases of atrial fibrillation may be inherited. Genetic disorders that cause connective tissue disorders are also associated with stroke from hemorrhage; they include polycystic kidney disease, Ehlers-Danlos syndrome type IV, neurofibromatosis type 1, Marfan's syndrome, and moyamoya disease. Specific Genetic Factors Under Investigation. Specific genetic factors are under investigation. They include:
Mental and Emotional FactorsStress. One survey revealed that men who had a more intense response to stressful situations, such as waiting in line or problems at work, were more likely to have strokes than those who did not report such distress. In some people, prolonged or frequent mental stress causes an exaggerated increase in blood pressure, which in turn can increase the risk for stroke. Depression. Depression has also been linked to higher risk for stroke and lower stroke survival rates. In one study, patients with severe depression had a 73% higher risk for stroke, and those with moderate depression had a 25% higher risk than average. The risk for stroke in African-Americans with depression was 160% higher than average. Migraine and Associated Risk FactorsStudies indicate that migraine or severe headache may be a risk factor for stroke in both men and women, especially before age 50. Overall, between 2 - 3% of ischemic strokes occur in people with a history of migraine. However, in patients under age 45, about 15% of all strokes (and 30 - 60% of strokes in young women) are associated with a history of migraines, particularly migraine with aura. Some evidence suggests that some strokes in these cases may be due to excessive activation of the nervous system and the dehydration from vomiting that occurs during a severe migraine with aura. The actual risk itself for migraineurs is low, however. In one study, women with migraines had a 2.7% risk of stroke, with the greatest risk between the ages of 45 - 65. Studies suggest specific risk factors for younger women with migraines, particularly those with auras, include taking high-estrogen oral contraceptives (OCs). (Whether progesterone-alone contraceptives carry any risk is unknown.) In migraineurs who take OCs, the risk increases with high blood pressure, smoking, or both. Infections and InflammationInflammation that occurs with various infections has been associated with stroke. One study found that patients hospitalized for stroke were three times more likely than patients without strokes to have recently been exposed to infections, usually mild ones in the respiratory tract. Varicella Virus. Varicella zoster virus (the virus that causes chicken pox and shingles) has been associated with cerebral vasculitis, a condition in which blood vessels in the brain become inflamed. It is a very rare cause of stroke in children. The virus has also been associated with some cases of stroke in young adults. Chlamydia Pneumonia. Some investigators suspect that some infections may produce inflammation in the arteries that can lead to stroke over time. (Similar work is underway in heart disease.) Researchers are particularly interested in Chlamydia pneumoniae, a non-bacterial organism that causes mild pneumonia in adults. Chronic infection has been linked with a higher risk for stroke, and evidence of the organism has been observed in thickened inner vessel walls of the carotid arteries in some studies. Chlamydia has also been linked to heart disease. Periodontal Disease. A number of studies now strongly support an association between periodontal disease and cardiovascular disorders. According to a major analysis, periodontal (gum) disease is associated with a 20% higher risk for ischemic stroke and heart disease. The added risk may be even greater in adults under 65. Recent evidence points to the inflammatory response as the common element. Peripheral Artery DiseasePeripheral artery disease (PAD) occurs when atherosclerosis affects the extremities, particularly the feet and legs. The major risk factors for heart disease and stroke are also the most important risk factors for PAD. The occurrence of such conditions in combination with PAD often signals more severe forms of heart or circulatory disease. Non-Steroidal Anti-Inflammatory Drugs (NSAIDs)In 2007, the American Heart Association (AHA) issued a scientific statement encouraging doctors to change the way they prescribe pain relief medication for patients at risk for heart disease or stroke. The AHA recommends that at-risk patients first try non-drug methods of pain relief (physical therapy, exercise, weight loss to reduce stress on joints, and heat or cold therapy). If these methods don’t work, patients should take the lowest possible dose of acetaminophen (Tylenol) or aspirin. COX-2 inhibitors, such as celecoxib (Celebrex), should be the last resort. In 2005, the FDA warned that all NSAIDs -- with the exception of aspirin -- carry heart risks. In particular, the NSAIDs ibuprofen (Advil, Motrin) and diclofenac (Cataflam, Voltaren) appear to carry increased risks for heart attack and stroke. Other Medical or Physical Conditions Associated with a Higher Risk for StrokeA number of medical or physical conditions may contribute to the risk for stroke:
Other Factors Associated with StrokeTiming. Like heart attack and sudden cardiac death, stroke appears to be more common in the morning hours, perhaps due to a temporary rise in blood pressure at that time. Various studies point to a higher risk for stroke on weekends, Mondays, and holidays. The risk for hemorrhagic stroke may also be higher in the winter, particularly in older people with high blood pressure. Homocysteine and Vitamin B Deficiencies. Abnormally high blood levels of the amino acid homocysteine, which occur with deficiencies of vitamin B6, B12, and folic acid, may be linked to an increased risk of coronary artery disease and stroke. Neck Manipulation. Some studies have reported a higher risk for stroke from injury to the carotid artery after neck manipulation by a chiropractor. PrognosisA stroke, the third leading cause of death in the U.S., is always serious. In 2004, over 150,000 Americans died of stroke with women accounting for 61% of these stroke deaths. The mortality rates are declining, however. Over 75% of patients survive a first stroke during the first year, and over half survive beyond 5 years. The Severity of an Ischemic Versus Hemorrhagic StrokePeople who suffer ischemic strokes have a much better chance for survival than those who experience hemorrhagic strokes. Among the ischemic stroke categories, the greatest dangers are posed by embolic strokes, followed by thrombotic and lacunar strokes. Hemorrhagic stroke not only destroys brain cells but also poses other complications, including increased pressure on the brain or spasms in the blood vessels, both of which can be very dangerous. Studies suggest, however, that survivors of hemorrhagic stroke have a greater chance for recovering function than those who suffer ischemic stroke. Factors that Affect Quality of Life in SurvivorsBetween 50 - 70% of people recover functional independence after a stroke. However, between 15 - 30% of those who survive either an ischemic or hemorrhage stroke suffer some permanent disability. On the encouraging side, one study reported that people who survived for many years after a stroke had a chance for independent living that was about the same as for their peers who had not suffered strokes. The stroke patients even appeared to be less depressed than the comparison group. The National Institutes of Health (NIH) have devised a scoring system that helps predict the severity and outcome of the stroke by scoring 11 factors (levels of consciousness, gaze, visual fields, facial movement, motor functions in the arm and leg, coordination, sensory loss, problems with language, inability to articulate, and attention). Up to 70% of patients with ischemic strokes who score less than 10 have a favorable outlook after a year, while only 4 - 16% of patients do well if their score is more than 20. Factors Affecting RecurrenceThe risk for recurring stroke is highest within the first few weeks and months. The risk is about 14% in the first year and about 5% thereafter, so preventive measures should be instituted as soon as possible. Some specific risk factors for early recurrence include:
PreventionForty percent of patients who have had a stroke or TIA will suffer a subsequent stroke within 5 years. In 2006, the American Heart Association/American Stroke Association released guidelines for preventing a second stroke. These guidelines recommend: Quit Smoking. Also avoid exposure to second-hand smoke. Maintain Weight. People should aim for a BMI index of 18.5 - 24.9. In people who are obese, reducing weight to this level can reduce the risk for stroke by 15% in men and 22% in women. Waist measurements should be no more than 35 inches for women and 40 inches for men. Exercise. Everyone in normal health should engage in at least moderate physical activity for a minimum of 30 minutes on most -- if not all -- days of the week. Limit alcohol. No more than 2 drinks a day for men and 1 drink a day for nonpregnant women. Healthy Diet. Everyone should aim for a diet that contains a healthy balance of fruits, vegetables, grains, fish, nuts, legumes, poultry, lean meat, and low-fat dairy items. Avoid saturated fats and trans fatty acids. Improve Cholesterol. People with at least two risk factors and a 10-year risk for heart disease or stroke of more than 20% should aim for LDL levels of less than 100 mg/dl. Raising HDL levels is important for people at risk for stroke. Statins are now used in most cases. Keep Blood Pressure Low. People in normal health should aim for 139/89 mm Hg or less. Patients with certain health problems, such as diabetes, should aim lower. Control Diabetes. People with diabetes should aim for fasting blood glucose levels of less than 110 mg/dl and hemoglobin A1C of less than 7%. Blood pressure goals should be 130/80 mm Hg or less. Take Aspirin or Other Antiplatelet Therapy. People at high risk for heart disease should take a low-dose aspirin every day, unless they have medical reasons to avoid aspirin. (As an alternative to aspirin alone, your doctor may prescribe clopidogrel alone or aspirin plus extended release dipyridamole.) Aspirin may help to prevent strokes caused by blockage in the artery (ischemic stroke), but it may slightly increase the risk of strokes caused by bleeding in the brain (hemorrhagic stroke). The American Heart Association recommends aspirin therapy for women over age 65 who are at risk for stroke. Control Atrial Fibrillation. People with atrial fibrillation should use anticoagulants to reduce their risk of blood clots. Carotid Endarterectomy Surgery or Stenting: Recommended for most symptomatic patients with neck artery stenosis (narrowing or blockage) of more than 70% and some patients with stenosis of 50 - 69%. Diet and Weight ControlA healthy diet rich in fruits and vegetables and low in salt and saturated fats may significantly lower the risk for both ischemic and hemorrhagic stroke. For diet plans, the Mediterranean diet may be a particularly good choice for reducing the risk of stroke. [See In-Depth Report #43: Heart-healthy diet.] Fruits and Vegetables. Studies suggest that people can protect their heart and circulation by eating plenty of fruits and vegetables. Eating at least five servings a day reduces blood pressure and protects against both heart attack and stroke. Important foods include most fruits (especially potassium-rich fruits including bananas, oranges, prunes, and cantaloupes) and vegetables (especially carrots, spinach, celery, alfalfa, mushrooms, lima beans, potatoes, avocados, broccoli). Vegetables, such as broccoli and kale, may be specifically protective against a first ischemic and possibly hemorrhagic stroke. Foods such as apples and tea, which are high in food chemicals called flavonoids, may also be very beneficial. Whole Grains and Nuts. A 2000 study reported a lower incidence in stroke in women who had a high intake of whole-grain foods. Nuts may also be protective. Calcium, Potassium, and Magnesium. Calcium, magnesium, and potassium serve as electrolytes in the body. They are important in controlling blood pressure and may also have protective effects against stroke: Some evidence suggests that diets rich in potassium may protect against stroke by 22 - 40%, mostly by reducing blood pressure but also possibly because of other mechanisms. Low potassium levels may increase the risk for stroke in certain people. A major study reported that calcium intake is associated with a lower risk for stroke in women, which supports an earlier study reporting a lower risk for stroke in men who drank more milk. Magnesium deficiencies may increase the risk for atrial fibrillation. No evidence yet exists, however, that taking magnesium supplements is protective. Salt Restriction. Although the effects of salt restriction are not entirely clear, a 2002 study indicated that even a modest reduction in salt intake for more than a month might reduce the risk of death from stroke by 14% in people with high blood pressure and 6% in people with normal blood pressure. Fats and Oils. The effects of fats and oils on stroke are complex. One study indicated that middle-aged men without heart disease who had the highest intake of monounsaturated or saturated fat (but not polyunsaturated oils) also had the lowest risk for stroke. Monounsaturated oils, obtained in olive and canola oils, may have protective benefits against both heart disease and stroke. Saturated fats, found in animal products, are known risk factors for heart disease. Some studies suggest, however, that low intake of animal protein and saturated fat increases the risk of hemorrhagic stroke. Other fat compounds that may be stroke protective are omega-3 fatty acids:
In any case, consuming fish two or three times a week helps the heart. VitaminsFolic Acid and B Vitamins. Deficiencies in the B vitamins folate (known also as folic acid), B6, and B12 have been associated with a higher risk for heart disease in some studies. Such deficiencies produce higher blood levels of homocysteine, an amino acid that has been associated with a higher risk for heart disease, stroke, and heart failure. Researchers have been studying whether vitamin B supplements can reduce homocysteine levels and, consequently, heart disease risks. Several major 2006 studies indicated that while B vitamin supplements help lower homocysteine levels, they have no effect on heart disease outcomes. The studies, published in the New England Journal of Medicine, examined patients who had either recently had a heart attack or suffered from diabetes or heart disease. Results showed a similar number of heart attacks and strokes among patients who took folic acid and B6 and B12 vitamins and those who received placebo. And, the vitamins seemed to increase risks for patients who had undergone stenting. Some experts think that homocysteine may be a marker for heart disease rather than a cause of it. Antioxidant Vitamins. The effects of antioxidant vitamins and carotenoids on stroke have been studied extensively. Most studies have found that these vitamins do not help protect against stroke. An important 2001 study reported no protection from stroke with vitamins A or E or beta carotene. A 2005 study in the Journal of the American Medical Association found that vitamin E definitely does not protect women from stroke or heart attack. Caffeine Intake, Alcohol, and SmokingSmoking. Everyone should quit smoking. Alcohol. Mild-to-moderate alcohol use (one to seven drinks a week) is associated with a significantly lower risk for ischemic stroke, although not hemorrhagic stroke. Heavy alcohol use, particularly a recent history of drinking, is associated with a higher risk of both ischemic and hemorrhagic stroke. Coffee. In healthy people with normal blood pressure, drinking a couple of cups of coffee a day is unlikely to do any harm. Caffeine may actually have nerve-protecting properties that may help stroke survivors. Caffeine drinkers, however, might do better to choose tea, which may have beneficial nutrients, and people with existing hypertension should avoid caffeine altogether (since caffeine may increase the risk for stroke in this group). ExerciseExercise helps reduce the risk of atherosclerosis, which can help reduce the risk of stroke. Experts recommend at least 30 minutes of exercise on most, if not all, days of the week. ![]() Hypertension is a disorder characterized by chronically high blood pressure. It must be monitored, treated, and controlled by medication, lifestyle changes, or a combination of both. Reducing Blood PressureReducing blood pressure is essential in stroke prevention. Lifestyle measures such as exercise, weight loss, and healthy diets are important for everyone. Drug therapy is recommended for people with hypertension who cannot control their blood pressure through lifestyle changes. Many different types of drugs are used to control blood pressure. They include ACE inhibitors, angiotensin-receptor blockers, beta-blockers, calcium channel blockers, and diuretics. Some drugs, such as Hyzaar, combine an angiotensin receptor blocker with a diuretic to both treat high blood pressure and prevent stroke. [See In-Depth Report #14: High blood pressure.] Lowering LDL and Raising HDL CholesterolIn 2004, the National Cholesterol Education Program issued updated recommendations on how to control cholesterol levels. These guidelines emphasize that patients should lower their LDL (“bad”) cholesterol and recommend that more people take LDL-lowering medication. Lowering LDL cholesterol and raising HDL (“good”) cholesterol can significantly reduce the risks of heart disease, including stroke. Statins have become the most important LDL-lowering drugs. Brands include lovastatin (Mevacor), pravastatin (Pravachol), simvastatin (Zocor), fluvastatin (Lescol), atorvastatin (Lipitor), and rosuvastatin (Crestor). Research increasingly suggests that lowering LDL levels as much as possible is critical for preventing stroke and other heart disease problems. A major analysis of over 200 studies found that statins reduced the risk for heart problems by 60% and stroke by 17%. Another study of over 20,000 people with cerebrovascular disease found that patients who took statin therapy for 2 years reduced their risk of ischemic stroke by 25%. Statins are proven to reduce the risk of stroke in people at increased risk for heart disease. Research suggests that they may also prevent stroke in patients without heart disease. However, current guidelines recommend that statins should be prescribed to patients without heart disease and with normal LDL levels only if diabetes and several heart disease risk factors are also present. Researchers are also investigating whether statins might be beneficial in preventing a second stroke in patients who have suffered a stroke or transient ischemic attack (TIA). A study published in 2006 in the New England Journal of Medicine indicated that high-dose atorvastatin (Lipitor) therapy may help reduce the risk of stroke recurrence and other heart events for patients who have had a prior stroke or TIA. In 2006, the FDA expanded atorvastatin’s indications to include reducing the risk of fatal and non-fatal strokes in patients with heart disease [See In-Depth Report #23: Cholesterol.] Influenza Vaccinations (Flu Shots)Influenza vaccinations may protect patients with a history of heart attack or heart events. A 2002 study further suggested that flu shots might protect against stroke, although possibly not in patients older than age 75. Atrial Fibrillation and Its TreatmentsTreatment for atrial fibrillation always includes drugs (aspirin or warfarin) to prevent clots from forming. In addition to anticoagulants (blood thinners), other approaches may include:
Important studies report that controlling heart rate may be the preferable approach. In several studies, rhythm control offered no survival advantages and did not protect against ischemic stroke. Therapies aimed at controlling heart rate, furthermore, had fewer complications. Drugs to Prevent Blood Clots After a diagnosis of atrial fibrillation, warfarin (an anticoagulant) or aspirin (an antiplatelet) are essential to prevent blood clots. These drugs can reduce the risk for stroke by over 60% in patients with atrial fibrillation.
Restoring and Controlling Heart Rhythm To initially restore heart rhythm, anti-arrhythmic drugs are usually tried first. If they fail to restore normal rhythm, cardioversion is often effective. (Some experts suggest trying cardioversion first to avoid side effects of the drugs.) Long-term maintenance therapy using anti-arrhythmic drugs may be required. Electrical Cardioversion. Electrical cardioversion is mild shock therapy and is the current standard treatment used to restore normal heart rhythm. It is conducted as follows:
Although the stabilizing effect is usually only temporary, some evidence suggests that a series of cardioversion may succeed in maintaining normal rhythm in young healthy patients without the need for antiarrhythmic medications. Low-energy implanted cardioverters (Atrioverter, Jewel AF) are being investigated for maintenance. Studies are promising. Drugs Used for Maintaining Normal Heart Rhythm. For maintaining a stable rhythm, the following drugs may be used. The specific choices typically depend on whether or not the patient has existing heart disease:
Amiodarone is more effective than most others and has been thought to be safer than many other similar drugs. Even in low doses, however, there is a high incidence of side effects, including thyroid disorders, neurologic, skin, and eye problems, and abnormally slow heart beats. Many of these drugs carry a small but significant increased risk, however, for a life-threatening arrhythmia called torsades de pointes. People with certain heart conditions should avoid these drugs. Surgical Procedures for Complex AF. In some difficult cases, surgery may be recommended. The options and candidates depend on other complicating factors. The following are some examples:
Controlling Heart Rate Drugs Used to Control Heart Rate. Beta-blockers or calcium channel blockers are used to control heart rate at the onset of atrial fibrillation. Digitalis, an older drug, is not used as often but can be effective in combination with the other drugs. DiagnosisPreventing a major stroke in people who experience transient ischemic attacks or small strokes requires determining the source of such attacks. A complete blood count, chest x-ray, and electrocardiogram are usually performed. Discouragingly, a 2001 study reported that over 30% of patients with TIA who called their primary care doctor were neither evaluated nor sent to the hospital within the month after a first event. Examining the Carotid Artery. The doctor examines the carotid artery to determine if it is severely narrowed. If so, the patient is in danger of a major stroke. (The thickness of the carotid artery is also an important indicator for long-term risks for stroke, as well as heart disease and mortality rates in general.) The doctor may use a number of approaches to determine the thickness of the artery:
![]() Carotid duplex is an ultrasound procedure performed to assess blood flow through the carotid artery to the brain. High-frequency sound waves are directed from a hand-held transducer probe to the area. These waves "echo" off the arterial structures and produce a two-dimensional image on a monitor, which will make obstructions or narrowing of the arteries visible. Imaging Techniques for TIAs. Several imaging techniques may identify small clots or other indicators of risk in the brain. General Guidelines for Diagnosing a Major StrokeIdentifying a Stroke Quickly. To save a patient's life, a fast diagnosis of both the presence and type of stroke is critical. Health professionals have devised different tests to help emergency workers quickly identify a person with stroke even before they reach the hospital. For example, an assessment tool called Face, Arms, Speech, Time (FAST) is highly accurate. It involves watching for the following signs:
Determining Ischemia Versus Hemorrhagic Stroke. Once a stroke has been identified, the next important step is to determine as quickly as possible whether it is hemorrhagic or ischemic. Clot-busting drug therapies can be life-saving for ischemic stroke patients, but they are effective only in the first 3 hours. In addition, they cause bleeding and can be lethal if the stroke is caused by a hemorrhage. A computed tomography (CT) scan is essential for identifying or ruling out hemorrhagic strokes. The goal is to complete the CT examination and obtain and interpret the results within 45 minutes of arrival at the hospital. (An ultrasound technique called transcranial duplex sonography may be sensitive enough to differentiate between hemorrhagic and ischemic strokes if CT scans are not available.) Certain factors suggest a hemorrhagic rather than ischemic stroke. They include specific symptoms (coma, vomiting, and severe headache), taking anticoagulants, very high systolic blood pressure, or high blood sugar levels in nondiabetics. However, such findings are not conclusive, and a CT scan or MRI is always needed. Ruling Out Other Disorders. In most cases of stroke, the diagnosis is evident although a number of conditions may cause similar symptoms. These include seizures, infections that cause mental confusion, syncope (fainting), hypoglycemia, and brain tumors. Imaging Tests Used for Stroke and Risk Factors for StrokeMagnetic Resonance Imaging (MRI). MRI uses a magnetic field to provide 3-dimensional images of the brain. In 2007, an important Lancet study of emergency room patients clearly indicated that MRI is superior to computed tomography (CT) in assessing whether a stroke has occurred. The MRI appears to work especially well for detecting ischemic stroke (stroke caused by blood clot). In the study, MRI accurately detected presence or absence of acute stroke in 80% of patients compared to 58% for CT. (Acute stroke included both ischemic and hemorrhagic types.) MRI detected acute ischemic stroke in 40% of patients compared to 10% for CT. In addition, MRI detected ischemic stroke within 3 hours of symptom onset (an important timeframe for delivering clotbuster drugs) in 46% of patients compared to only 7% for CT. Both MRI and CT performed similarly for detecting hemorrhagic stroke. Computed Tomography. A computed tomography (CT) test uses x-ray images to take pictures of the skull and brain. Sometimes a dye is injected into a patient’s veins to enhance image contrast. Although research indicates that MRI is better in determining ischemic stroke, CT still may be useful in diagnosing hemorrhagic strokes. Ultrasound. Ultrasound may be used in different circumstances. This imaging technique is painless and noninvasive.
Other Techniques. Other imaging tests, including positron-emission tomography (PET) and single photon-emission computed tomography (SPECT), may also help the doctor identify injuries caused by the stroke. Heart EvaluationElectrocardiogram (ECG). A heart evaluation using an electrocardiogram (ECG) is important in any patient with a stroke or suspected stroke. An ECG records the electrical current in the heart muscle. Echocardiogram. An echocardiogram uses ultrasound to view the chambers and valves of the heart. It is generally useful for stroke patients to identify blood clots or risk factors for blood clots that can travel to the brain and cause stroke. There two are types:
ABCD2 ScorePatients who have a TIA are at increased risk for a major stroke in the days and weeks that follow. The ABCD2 score is a tool that helps doctors predict short-term stroke risk following a TIA. The ABCD2 score assigns points for various factors:
Based on the number of points, a doctor can identify whether a patient is at low, moderate, or high risk of having a subsequent stroke within 2 days after a TIA. Several 2006 and 2007 studies indicated that the ABCD2 score works well in predicting stroke, and can help doctors better decide which patients require hospitalization and emergency care. Other TestsBlood Tests. Several blood tests may help predict the risk for a stroke and determine the severity and complications of an existing stroke.
Examination of Spinal Fluid. If the CT scan is negative but the doctor still suspects a subarachnoid hemorrhagic stroke, a spinal tap may be performed. Spinal fluid containing significant amounts of blood will usually confirm a hemorrhagic stroke. Managing a StrokeUntil recently, the treatment of stroke was restricted to basic life support at the time of the stroke and rehabilitation later. Now, however, treatments can be dramatically beneficial when administered as soon as possible after the onset of the stroke. It is critical to get to the hospital and be diagnosed as soon as possible. There are several steps in the initial assessment and management of a person with a stroke. Get to the Hospital ImmediatelyIf significant symptoms appear in people at risk for stroke, calling 911 is critical (as opposed to calling the family doctor or trying to get the patient to the hospital by car). One study reported that patients who went to the emergency room in an ambulance had a much shorter delay in getting treatment than those who went on their own. Receiving treatment early is critical in reducing the damage from a stroke. Make an Immediate Diagnosis and Evaluation of the PatientImportant diagnostic and evaluation steps are needed for the optimal treatment of a stroke patient: Determine Whether the Stroke Is Ischemic or Hemorrhagic. As soon as the patient enters the hospital, diagnostic tests, particularly a CT scan, should occur to determine whether the stroke is ischemic or hemorrhagic. Determine The Need for Thrombolytic Drugs. If the stroke is ischemic, the next step is to determine if the patient would benefit from blood clot-busting drugs (called thrombolytics). The following factors can assist in making this decision:
Give Supportive TreatmentThe patient should receive treatment to support basic life functions and to reduce stress, pain, and agitation. The following steps are also very important: Maintain Adequate Delivery of Oxygen. It is very important to maintain oxygen levels. In some cases, airway ventilation may be required. Supplemental oxygen may also be necessary for patients when tests suggest low blood levels of oxygen. Hyperbaric oxygen (which is oxygen administered under pressure) may help specific stroke patients, although it is not recommended for most patients, since there is some risk of significant adverse effects using this approach. Managing Fever and Lowering Body Temperature (Hypothermia). Fever should be aggressively treated, since strong evidence suggests that its presence predicts a poorer outlook. Some evidence suggests that hypothermia -- reducing body temperature -- might protect nerve cells in stroke patients. Cooling is done through special cooling blankets, ventilators, or infusion of cool fluids. Unfortunately, severe side effects occur with even moderate hypothermia (86°F, 30°C), which can include pneumonia, blood clotting disorders, heart rhythm disturbances, and others. Maintain Electrolytes. Maintaining a healthy electrolyte balance (the ratio of sodium, calcium, and potassium in the body's fluids) is critical. Managing Blood Pressure. Managing blood pressure is essential and complicated. Patients with stroke and pressures above 220 (systolic) or 120 (diastolic) should be treated. Lowering blood pressure too quickly can be dangerous, however, in patients with both ischemic and hemorrhagic strokes. In general, experts do not advise aggressively lowering elevated pressures below 220/120 mm Hg in patients unless they have other conditions, such as a heart attack, that require pressure-lowering treatments. In patients who require thrombolytic drugs, blood pressure should cautiously be lowered to 185/110 mm Hg. In most cases, blood pressure declines when these patients become stabilized. Managing Increased Brain Pressure. Hospital staff should watch carefully for increased pressure on the brain, which is a frequent complication of hemorrhagic strokes. It can also occur a few days after ischemic strokes. Early symptoms of increased brain pressure are drowsiness, confusion, lethargy, weakness, and headache. Medications such as mannitol may be given during a stroke to reduce pressure or the risk for it. Keeping the top of the body higher than the lower part, such as by elevating the head of the bed, can reduce pressure in the brain and is standard practice for patients with ischemic stroke. However, this practice also lowers blood pressure in general, which may be dangerous for patients with massive stroke. Monitoring the Heart. Heart attack and arrhythmias are potential complications of ischemic stroke. Patients must be monitored using electrocardiographic tracings. Controlling Glucose Levels. Elevated blood sugar (glucose) levels can occur with severe stroke and may be a marker of serious trouble. In general, it is advisable to lower glucose levels that are about 300 mg/dL, usually with insulin. It is not clear, however, if glucose-lowering treatments offer any advantage. Excessive lowering of glucose levels can have damaging effects on the brain. Studies are underway to determine the best approach. MedicationsIntravenous Thrombolytics. Clot-busting (thrombolytic) drugs break up existing blood clots. They are among the important treatments for heart attacks, and are now also used for ischemic (not hemorrhagic) stroke. While research has confirmed that early treatment with thrombolytics can greatly increase a stroke patient's chances for recovery, their use has been limited due to the short treatment window (within 3 hours of onset of stroke symptoms). The standard thrombolytic drugs are tissue plasminogen activators (t-PAs). They include alteplase (Activase) and reteplase (Retavase). The following steps are critical before administering these clot-buster drugs:
Thrombolytics carry a risk for hemorrhage, so they may not be appropriate for patients with existing risk factors for bleeding. They should not be used in patients who are experiencing seizures. The drug may be appropriate in more patients than previously thought, however, including older people, those with a history of stroke, and those with high blood pressure. Although older studies cited concern over the safety and effectiveness of t-PA, a 2004 review of clinical trial data found that patients who received t-PA were two times more likely to experience a favorable outcome than those who did not receive this treatment. Intra-Arterial Thrombolytics. Researchers are investigating thrombolytics injected directly into an artery in the brain. Early studies suggest this approach may allow effective treatment up to 6 hours after a stroke and improve recovery in more patients. The risk for bleeding and hemorrhagic stroke is significantly increased, however. Fibrin-Depleting Drugs. These drugs deplete the amount of fibrinogen in blood, which in turn reduces the "stickiness" in blood. Such drugs include ancrod and batroxobin (Defibrase), both derived from the venom of poisonous snakes. Some experts believe these drugs might be a possible alternative to thrombolytics. Studies suggest they may modestly reduce the risks for death and disability if given early on. As with all anti-clotting drugs, there is a higher risk for hemorrhage, but it appears to be slight. Anticlotting Medications for Preventing a Recurring StrokeMedications that prevent blood from clotting are used to prevent a recurring or second stroke. Anticlotting drugs include antiplatelets and anticoagulants. Antiplatelet Drugs.Blood platelets are involved in blood clotting. Antiplatelets prevent clotting by blocking the accumulation of platelets. An antiplatelet drug -- most often aspirin -- is given within 48 hours of an ischemic stroke and continued in low doses as maintenance therapy. Studies suggest that antiplatelet therapy can reduce the risk for a second stroke by 25%.
Anticoagulants.Anticoagulants thin blood and may be useful under certain circumstances.
All anti-clotting drugs carry a risk for bleeding and a slightly increased risk for hemorrhagic stroke. Other Medications for Preventing a Recurring StrokeIt is important that patients control their high blood pressure and LDL (“bad”) cholesterol levels. Various drugs, such as statins, diuretics, and ACE inhibitors, can manage these conditions. People with diabetes should also maintain tight control of their blood sugar levels. Drugs for Hemorrhagic StrokeCalcium Channel Blockers. Early administration of calcium channel blockers, such as nimodipine (Nimotop), can improve functional outcome. One of the most common and serious dangers after a subarachnoid hemorrhagic stroke is spasm of the blood vessels near the ruptured site, which closes off oxygen to the brain. Calcium causes contraction of the smooth muscles of the blood vessels; calcium channel blockers are drugs that relax the blood vessels. The drugs work best if they are administered within 6 hours of the stroke. Calcium channel blockers are not useful for ischemic strokes, although they can be used in combinations with blood pressure lowering drugs to prevent them. Investigative Therapies to Protect or Restore Nerve Cells after a StrokeNerve-Protecting Drugs. More than 50 medications have been studied in clinical trials aimed at slowing or preventing the cascading process that destroys nerve cells after a stroke. Many investigative drugs are targeting the excitatory amino acids, such as glycine and glutamate, which are known to destroy nerve cells after a stroke. Although none to date have proven to have any significant benefits, some are showing promise. They include magnesium sulfate, citicoline, ebselen, piracetam, edaravone, albumin, erythropoietin, and NXY-059. Investigative Drugs for Nerve Regeneration. Scientists used to think that when cells in the brain were destroyed, new ones could not grow to replace them. Researchers have now observed, however, that nerve regrowth (neurogenesis) can occur in the adult human brain. This exciting discovery opens the way for new drugs that might in the future stimulate nerve growth and repair damage done by many neurologic diseases, including stroke. For example, a 2002 study reported nerve regeneration in animals whose brains were treated with the drug inosine. More research is underway. SurgeryCarotid EndarterectomyCarotid endarterectomy is a surgical procedure that cleans out and opens up the narrowed carotid artery. It is used in patients at high risk for thrombotic ischemic strokes, which are caused by blockages in the internal carotid artery. It is also sometimes used after a stroke. In such cases, patients have reported improvements in vision, speech, swallowing, functioning of arms and legs, and general quality of life. There is a risk of a heart attack or stroke from the procedure. Anyone undergoing this procedure should be sure their surgeon is experienced in recent techniques and that the medical center has complication rates of less than 6%. A 2000 study reported that older surgeons had a worse record than younger ones, possibly because they relied on residents or were less likely to adopt new procedures. Procedure Description. The procedure generally is as follows:
![]() Endarterectomy is a surgical procedure removing plaque material from the lining of an artery. Determining Who Should Have Surgery. Evidence strongly suggests that most patients with severe stenosis (over 70% of the carotid artery is obstructed) can benefit from either carotid endarterectomy or carotid artery stenting. An experienced surgeon with a good track record is essential. Patients with mild stenosis (less than 50% obstruction) should not have endarterectomy; these patients do better with medications even if they have symptoms. For patients with moderate stenosis (50 - 69%), the decision to perform surgery needs to be determined on an individual basis. When a carotid endarterectomy procedure is recommended, it should be performed within 2 weeks. Carotid Angioplasty and StentingCarotid angioplasty and stenting (CAS) is being investigated as a less-invasive alternative to carotid endarterectomy. It is based on the same principles as angiography done for heart disease.
This procedure carries a risk for an embolic stroke and other complications. At this time, it is being used in some centers as an alternative to endarterectomy in patients who cannot undergo endarterectomy, especially for patients with severe stenosis (blockage greater than 70%) and high surgical risk. Several studies published in 2006 suggested that CAS should be used only for patients with these types of conditions. One of these trials, EVA-3S, was stopped early because results clearly indicated a higher 30-day risk of death and stroke in patients who underwent CAS. Experts are waiting for results of further trials comparing stenting and endarterectomy. HemicraniectomyHemicraniectomy is surgical removal of a bone patch from the skull to relieve pressure. The bone is stored under sterile conditions and reimplanted a few months latter. It may have be a life-saving option for some patients with severe stroke that has resulted in swelling and injury to a large area in the brain. Studies are showing some benefits for high-risk patients, but more information is needed to determine specific conditions that will respond to this treatment. Extracranial-Intracranial BypassExtracranial-intracranial (EC-IC) bypass has been under investigation for decades for ischemic stroke, but has had very mixed results, some extremely negative. With this procedure, a healthy artery in the scalp is rerouted to an area of the brain that was deprived of blood because of a blocked artery. This procedure is now sometimes used for patients with aneurysms. Some experts hope, however, that, in specific cases chosen via careful imaging and using the latest surgical techniques, EC-IC may prove to be helpful for some stroke patients. Surgery for Preventing and Treating Hemorrhagic StrokesSurgical Intervention of the Ruptured Aneurysms. In patients with subarachnoid hemorrhagic stroke, surgery to block off the aneurysm is usually recommended within a few days of the stroke. The standard procedure is to clip the aneurysm and stop bleeding. Alternative approaches are promising. Surgical Intervention of Unruptured Aneurysms. If an unruptured aneurysm is detected, patients should discuss all options with their doctor, including surgical repair. Unruptured aneurysms occur in between 1 - 8% of the general population, however, and controversy exists over when to operate and on which patients. In general, the decision rests on the size of the aneurysm, but uncertainty still exists. In one study, for example, the risk of rupture for aneurysms between 10 - 25 mm was quite low -- slightly less than 1% per year for both groups. Aneurysms over 25 mm, however, had a 6% chance of rupturing within a year. Studies have reported that in general, the risk for rupture is between .05 - 2% a year, but recent evidence suggests that the risks may be even less. In one study, even people with a history of subarachnoid hemorrhage had only a 0.5% annual risk for recurrence when aneurysms were small. Aneurysms can often cause symptoms, however, even if they do not rupture. Patients should discuss their particular risk factors carefully with their doctors. Individuals with arteriovenous malformation, a condition caused by abnormal associations between arteries and veins, should be monitored for the development of an aneurysm. Clipping the Aneurysm. The standard surgical procedure for treating a ruptured aneurysm is to place a clip across the neck of the aneurysm, which blocks off bleeding. It is usually performed within the first 3 days. Getting to the aneurysm is often extremely difficult. Deep cooling of the body to stop circulation may be used to allow more time for the operation. Procedures that remove large portions of the bone in the skull are being developed to allow fast access. There is a relatively high risk for newly formed aneurysms, particularly after 9 years. Patients may want to discuss follow-up angiography to detect any new aneurysms 9 - 10 years after the procedure. Transcatheter Embolization for Sealing off the Aneurysm. Transcatheter embolization is a new technique for ruptured and unruptured aneurysms that is proving to be effective, although it is still investigational. The surgeon threads a thin tube through the artery leading to the aneurysm through which materials are passed to plug or obstruct the aneurysm. In one version of this procedure, the following occurs:
A 2002 study suggested it could be attempted safely in over 95% of patients with unruptured aneurysms. In the study, the procedure eliminated the aneurysm in nearly 90% of the patients. In small trials using the coil with a ruptured aneurysm, only 3.7% of patients suffered a second stroke after 7 months compared to the usual re-rupture rate of 30 - 40%. Emergency Surgery for Hemorrhagic Strokes. Emergency surgery for a hemorrhagic stroke involves locating and removing large blood clots. In the past, such procedures had little effect on survival. Advances, however, are improving outcomes when surgery is performed very early. RecoveryAfter a stroke, patients should take all necessary measures, including medications and lifestyle changes, to prevent another stroke. For those whose stroke was ischemic, aspirin, warfarin, or both will usually be prescribed. Having a neurologist as the primary doctor after a stroke, rather than some other specialist or primary care doctor, significantly increases the chance for survival. Patients or their families should be persistent in requesting the best care possible during this important early period. Receiving initial treatment at a stroke unit, instead of a general ward, plays a strong role for better long-term quality of life. Rehabilitation services aimed at patients living at home are also very effective in improving independence. Patients or their families should seek patient advocates or support associations to ensure they receive the right care. Reducing the Risk for Non-Neurologic Complications after a StrokeIn addition to problems brought on by neurologic damage, stroke patients are also at risk for other serious problems that reduce their chances for survival. They include:
Measures should be taken to monitor and treat patients for these important problems. Candidates for RehabilitationIn all, 90% of stroke survivors experience varying degrees of improvement after rehabilitation. The current cost-cutting climate generates pressure to send elderly patients who have had a stroke directly to a nursing home rather than a rehabilitation first. Not all patients, however, need or benefit from formal rehabilitation:
Positive factors that help predict good candidates for rehabilitation:
Factors that predict a poor response to rehabilitation:
Factors that do not rule out rehabilitation:
Some Approaches to RehabilitationPhysical therapy should be started as soon as the patient is stable, as early as 2 days after the stroke. Some patients will experience the fastest recovery in the first few days, but many will continue to improve for about 6 months or longer. Because stroke affects different parts of the brain, specific approaches to managing rehabilitation vary widely among individual patients:
Drug Therapy for RehabilitationDrug therapy can sometimes help relieve specific effects of stroke:
Certain drugs commonly taken for conditions associated with stroke may actually slow recovery. They include drugs used for high blood pressure, including clonidine and prazosin, anticonvulsant drugs, the antipsychotic drug haloperidol, and anti-anxiety drugs such as benzodiazepines. Managing the Emotional ConsequencesThe Emotional State of the Patients. Strong motivation with the goal of independence after rehabilitation is important for recovery. Unfortunately, depression is very common after a stroke, both as a direct and indirect result of the stroke:
If depression is prolonged, it can interfere with recovery. One study showed that people who suffered strokes and became depressed were three times more likely to die within 10 years than stroke victims who were not depressed. There is a significantly increased risk of suicide in patients with stroke, especially in women and those under age 60. Antidepressants, particularly fluoxetine (Prozac) and similar so-called SSRI drugs, have been beneficial in relieving post-stroke crying as well as improving recovery in general and mood in particular. Antidepressants may also help restore mental abilities. Some doctors also recommend tricyclic antidepressants, which include amitriptyline (Elavil) and nortriptyline (Pamelor). In one study nortriptyline (Pamelor) not only improved mood but also had positive effects on mental functioning, suggesting perhaps that some dementia associated with stroke may actually be due to depression. Tricyclics may also be useful for neurologic emotionalism. Anxiety disorder is also common and debilitating. Some research indicates that many patients suffer from feelings identical to post-traumatic stress syndrome. The two disorders often overlap, but drug treatments for each differ and may offset the other. Many drugs for psychologic disorders affect the central nervous system and can delay rehabilitation. Skilled professional help is needed to determine the most effective and safest treatments. The Emotional State of the Caregiver. The caregiver's emotions and responses to the patient are critical. Patients do worse when caregivers are depressed, overprotective, or not knowledgeable about the stroke. Unfortunately, in one study, over half of the caregivers themselves were depressed, particularly if the stroke victims were left with dementia or abnormal behavior. Resources
ReferencesACTIVE Writing Group on behalf of the ACTIVE Investigators; Connolly S, Pogue J, Hart R, Pfeffer M, Hohnloser S, et al. Clopidogrel plus aspirin versus oral anticoagulation for atrial fibrillation in the Atrial fibrillation Clopidogrel Trial with Irbesartan for prevention of Vascular Events (ACTIVE W): a randomised controlled trial. Lancet. 2006 Jun 10;367(9526):1903-12. Amarenco P, Bogousslavsky J, Callahan A 3rd, Goldstein LB, Hennerici M, Rudolph AE, et al. High-dose atorvastatin after stroke or transient ischemic attack. N Engl J Med. 2006 Aug 10;355(6):549-59. Antman EM, Bennett JS, Daugherty A, Furberg C, Roberts H, Taubert KA. Use of nonsteroidal antiinflammatory drugs: an update for clinicians: a scientific statement from the American Heart Association. Circulation. 2007 Mar 27;115(12):1634-42. Epub 2007 Feb 26. Chalela JA, Kidwell CS, Nentwich LM, Luby M, Butman JA, Demchuk AM, et al. Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison. Lancet. 2007 Jan 27;369(9558):293-8. ESPRIT Study Group; Halkes PH, van Gijn J, Kappelle LJ, Koudstaal PJ, Algra A. Aspirin plus dipyridamole versus aspirin alone after cerebral ischaemia of arterial origin (ESPRIT): randomised controlled trial. Lancet. 2006 May 20;367(9523):1665-73. Johnston SC, Rothwell PM, Nguyen-Huynh MN, Giles MF, Elkins JS, Bernstein AL, et al. Validation and refinement of scores to predict very early stroke risk after transient ischaemic attack. Lancet. 2007 Jan 27;369(9558):283-92. Kurth T, Gaziano JM, Cook NR, Logroscino G, Diener HC, Buring JE. Migraine and risk of cardiovascular disease in women. JAMA. 2006 Jul 19;296(3):283-91. Mas JL, Chatellier G, Beyssen B, Branchereau A, Moulin T, Becquemin JP, et al. Endarterectomy versus stenting in patients with symptomatic severe carotidstenosis. N Engl J Med. 2006 Oct 19;355(16):1660-71. Mosca L, Banka CL, Benjamin EJ, Berra K, Bushnell C, Dolor RJ, et al. Evidence-based guidelines for cardiovascular disease prevention in women: 2007 update. Circulation. 2007 Mar 20;115(11):1481-501. Rosamond W, Flegal K, Friday G, Furie K, Go A, Greenlund K, et al. Heart disease and stroke statistics -- 2007 update: a report from the American Heart Association Statistics Committee and Stroke Statistics Subcommittee. Circulation. 2007 Feb 6;115(5):e69-171. Epub 2006 Dec 28. SPACE Collaborative Group; Ringleb PA, Allenberg J, Bruckmann H, Eckstein HH, Fraedrich G, et al. 30 day results from the SPACE trial of stent-protected angioplasty versus carotid endarterectomy in symptomatic patients: a randomised non-inferiority trial. Lancet. 2006 Oct 7;368(9543):1239-47. Thavendiranathan P, Bagai A, Brookhart MA, Choudhry NK. Primary prevention of cardiovascular diseases with statin therapy: a meta-analysis of randomized controlled trials. Arch Intern Med. 2006 Nov 27;166(21):2307-13. Tsivgoulis G, Spengos K, Manta P, Karandreas N, Zambelis T, Zakopoulos N, et al. Validation of the ABCD score in identifying individuals at high early risk of stroke after a transient ischemic attack: a hospital-based case series study. Stroke. 2006 Dec;37(12):2892-7. Epub 2006 Oct 19. Wolf SL, Winstein CJ, Miller JP, Taub E, Uswatte G, Morris D, et al. Effect of constraint-induced movement therapy on upper extremity function 3 to 9months after stroke: the EXCITE randomized clinical trial. JAMA. 2006 Nov 1;296(17):2095-104.
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