Stroke

Overview

A dangerous situation

Each year, more than 500,000 Americans experience a stroke and 144,000 of them die. Of those people, 67% suffer resulting disabilities. The remaining one-third may make a full recovery.

Although the death rate from stroke has declined sharply over the past 25 years, it appears to have leveled off and remains the third leading cause of death in the United States (after heart attack and cancer). It is also the leading cause of institutional placement and loss of independence among adults.

A stroke occurs when the blood flow to the brain is disrupted and the brain cells die due to a lack of oxygen. The symptoms and signs of stroke reflect the damage done to the brain, not necessarily the affected artery.

Detailed Description

In Western countries, stroke is the third most common cause of death and the second most common cause of disability after Alzheimer's disease. The disabilities caused by stroke include varying degrees of paralysis, speech problems, visual disorders, and impaired memory. These occur when a blood clot or ruptured blood vessel cuts off the brain's blood supply.

Exactly how a stroke affects a person depends on where in the brain it occurs. If, for example, a blood vessel in the area of the brain that controls movement of the right arm becomes blocked, then that arm will be weak or paralyzed.

Strokes generally fall into one of the following categories:

  • Thrombotic stroke: the most common type; occurs when a blood clot forms in an artery supplying blood to the brain. Often preceded by "mini-strokes," or transient ischemic attacks (TIAs), during which blood flow to the brain is temporarily disrupted.
  • Cerebral embolism: occurs when a clot forms elsewhere in the body, travels through the bloodstream, and lodges in the brain.
  • Cerebral hemorrhage: occurs when a weakened blood vessel in the brain ruptures.
  • Subarachnoid hemorrhage: occurs when the blood vessel bleeds into a space between the brain and skull.

The extent to which a stroke victim is able to function normally following a stroke depends upon three things:

  • The severity of the stroke
  • The speed at which medical intervention is initiated
  • The early introduction of active, ongoing rehabilitation therapy

It is important to note that some stroke victims recover all or most of their pre-stroke abilities over time. About 50% of patients with one-sided paralysis and most of those with less severe symptoms recover some function before they leave the hospital. Stroke related disabilities that remain after six months are likely to be permanent, although some people continue to improve slowly.

Characteristics of Strokes

Most strokes begin suddenly, develop rapidly, and cause brain damage within minutes; however, doctors can sometimes reduce or prevent further damage by acting quickly. Clot-dissolving drugs such as streptokinase and tissue plasminogen activator (TPA) may be effective in reversing or preventing paralysis and other symptoms if administered within three hours of a stroke's onset.

Following a stroke, some brain tissue may be permanently dead. Although some people nonetheless recover full use of their faculties, others may not. Intensive rehabilitation therapy, however, helps most stroke victims learn to manage successfully. Patience, perseverance, and the support and understanding of family and friends are crucial to success.

How Common Are Strokes?

Strokes are the third largest cause of death (ranking only behind heart disease and cancer) and are a leading cause of serious, long-term disability in the United States. Strokes most often occur in the seventh and eighth decades of life, though risk begins at age 45. Males are approximately three times more likely than females to suffer from a stroke.

What You Can Expect

Warning signs of a stroke include:

  • Numbness or abnormal sensations in the face, arm, and/or leg on one side of the body
  • Sudden weakness or paralysis of the face, arm, and/or leg on one side of the body
  • Severe headache, with or without vomiting
  • Acute confusion, restlessness, disorientation, drowsiness, or loss of memory
  • Loss of balance, unsteady gait, dizziness
  • Double vision, dimness, or loss of vision in one eye
  • Slurred speech, loss of speech, or difficulty understanding speech

Conventional Treatment

Goals of Treatment

The goal of treatment is to help stroke victims recover all, or as many as possible, of their normal functions. The first step of treatment is to prevent the death of brain tissues as much as possible. Time is of the essence. At the first sign of stroke, people should seek help immediately. If early intervention is possible, physicians may be able to use drugs such as TPA to reverse paralysis.

Rehabilitation, which begins as soon as the person has been stabilized, includes physical, occupational, and speech therapy, as well as emotional counseling and in certain cases, neuropsychological treatment.

There is no cure for stroke. Brain tissues that have been destroyed by a stroke cannot be replaced or regenerated. Drugs are used to stabilize a person who has experienced a stroke and intensive rehabilitation therapy is conducted to help regain lost functions.

Treatment Overview

Treatment for stroke revolves primarily around stabilizing the person who has experienced the stroke and treating its aftermath. Various drug therapies are used to stabilize the condition and intense physical therapies are used to help restore affected functions. Prevention is also a key concern of health professionals. Controlling such things as high blood pressure can reduce the risk of a stroke substantially. Blood pressure control alone reduces stroke risk by 50% or more. Treating atrial fibrillation, a type of heart arrhythmia that is often ignored because it usually produces only minor symptoms, also decreases the likelihood of a stroke. In addition, numerous studies have shown that one aspirin taken daily may help lower the risk of stroke.

In the acute phase, inpatient care or hospitalization is recommended so that cardiac and pulmonary functions may be closely monitored. After this period, it is recommended that physical, occupational, and speech therapy begin either on an outpatient basis, in a nursing home, scheduled visits to a rehabilitation center, or at home. If blood clot removal is necessary, surgery is performed. Short- or long-term professional counseling may be needed as well, since depression can follow a stroke.

Drug Therapy

Drugs most commonly prescribed

Nimotop

On-Label Efficacy

Plavix
http://www.nmihi.com/c/clopidogrel.html

On-Label Efficacy

Altace

On-Label Efficacy

Mevacor

On-Label Efficacy

Pravachol

On-Label Efficacy

Lipitor
http://www.nmihi.com/a/atorvastatin.html

On-Label Efficacy

Zocor

On-Label Efficacy

Coumadin

On-Label Efficacy

Prozac

Off-Label Efficacy

Surgery

Surgery is generally of no help in the vast majority of stroke cases that are caused by a blood clot (ischemic stroke), because the brain tissue is already dead. If the patient has only suffered a transient ischemic attack (TIA), however, and the carotid artery is more than 70% blocked, surgery may help prevent future strokes by removing the blockage.

In cases of hemorrhagic stroke, which involve a ruptured blood vessel, surgery may be necessary to save the patient's life, although the injury and procedure often leave the person with severe neurologic disabilities. The goal, or goals, of surgery in these cases is to remove blood that has accumulated in the brain, relieve pressure, and repair a ruptured artery or aneurysm.

Healthcare Professionals Who May Be Involved in Treatment

Besides your family practitioner, the following specialists may be involved in managing a stroke in its acute phase:

  • Neurologists
  • Neurosurgeons
  • Vascular surgeons
  • Internists
  • Physiatrists
  • Ophthalmologists

In the rehabilitation phase of a stroke, health professionals include the following:

  • Physiatrists
  • Neurologists
  • Primary care physicians
  • Geriatricians
  • Physical therapists
  • Occupational therapists
  • Speech and language therapists
  • Neuropsychologists

Activity & Diet Recommendations

Diet

Patients are generally advised to partake of a low-fat, low-salt, high-fiber diet. It is also important to consider:

  • Eating more fruits and vegetables. Fruits and vegetables contain antioxidants and fiber that help prevent high blood pressure and atherosclerosis. In one study, Harvard researchers analyzed 20 years of diet and stroke data from the Framingham Heart Study. As fruit and vegetable consumption among participants increased, stroke risk decreased?— as much as 23% for those who had three daily servings.
  • Eating less meat. The fat in meats is associated with atherosclerosis, which clogs the arteries in the brain. According to Yale researchers, who studied 6,500 men between ages 57 and 67 over a ten-year period, daily meat consumption doubled the risk of stroke. Among the daily meat eaters, 12% had strokes. But among those who rarely ate meat, the stroke risk was just 5.4%.
  • Eat more fish. After monitoring the residents of a Dutch town for many years, researchers discovered that as fish consumption goes up, stroke risk goes down. Fish eaters tend to eat less meat. In addition, cold-water fish — for example, salmon — are high in the omega-3 fatty acids that help prevent strokes.

Exercise

Exercise regularly. Researchers at the National Center for Health Statistics followed 7,900 white and African-American adults for 12 years. Compared with those who were active, participants who got the least exercise were almost twice as likely to have strokes. Other studies have shown similar findings. Walking is excellent exercise for stroke prevention. Try to walk briskly for 30 to 60 minutes a day.

Possible Complications

Possible complications arising from a stroke include:

  • Subluxation of the shoulder
  • Dystrophy of the sympathetic nervous system
  • Depression

Quality of Life

While some people who suffer a stroke recover full use of their faculties, others may have physical and mental impairments that can interfere with eating, speaking, or moving. Physical and neurological gains are often incremental, and some disabilities may be permanent. Patients may have to make enormous physical and psychological shifts to adapt to a more restrictive lifestyle, which may include learning how to use a cane or wheelchair, or managing special eating utensils and grooming devices.

Stroke rehabilitation may take years of ongoing therapy. Family and friends can help a patient's recovery tremendously by maintaining a patient, cheerful, and loving attitude, and encouraging independence wherever and whenever safe and appropriate.

Stroke

Last updated 23 May 2012

Synonyms & Abbreviations

  • Cerebrovascular accident (CVA)
  • Reversible ischemic neurological accident (RIND)
  • Brain attack

Causes

Established Causes

A stroke occurs when a blood clot or ruptured blood vessel cuts off the brain's blood supply depriving the brain of oxygen. The conditions causing a stroke fall into one of the following categories:

  • Ischemic strokes. These account for approximately 75% of all strokes, and include the following types:
    • Large artery thrombosis: This affects about 25% of stroke victims; occurs when a blood clot forms in an artery supplying blood to the brain. This type of stroke is often preceded by "mini-strokes," or transient ischemic attacks (TIAs), during which blood flow to the brain is temporarily disrupted.
    • Cerebral embolism: This accounts for about 5% to 14% of strokes; occurs when an embolism, or clot, forms in the heart and travels through the bloodstream, lodging in the brain and blocking the flow of blood.
    • Lacunar strokes: These affect approximately 15% of stroke victims; they involve small arteries blocked by the formation of a thrombus, or clot.
    • Unknown causes: About 25% of ischemic strokes are caused by reasons not presently understood.
  • Intracerebral hemorrhage strokes. These affect approximately 15% of stroke victims; they can occur from the rupturing of a weakened blood vessel in the brain. They are usually caused by hypertension, hemorrhaging from anticoagulant drug use, rare bleeding disorders, arterial wall degeneration (more common in older people), or congenital defects of the arteries or veins that eventually cause rupturing.
  • Subarachnoid hemorrhage. This is responsible for about 7% of strokes; occurs when a blood vessel ruptures into a space between the brain and skull. Usually caused by a ruptured congenital aneurysm, arterial degradation (more common in older people), stimulant drug abuse, inflammation, or infectious diseases that involve brain surface arteries.

Drugs That Can Cause or Aggravate Strokes

Medications that slow clotting may increase the risk of hemorrhagic stroke. These include warfarin, heparin, aspirin, and such nonsteroidal anti-inflammatory drugs (NSAIDs) as ibuprofen (for example, Motrin). Also, Vesanoid (tretinoin) has been linked to cases of stroke.

Risk Factors

Risk factors for a stroke include the following:

  • Hypertension
  • Heavy smoking
  • Heart attack (myocardial infarction)
  • Atrial fibrillation
  • Diabetes mellitus
  • Alcohol abuse
  • Homocystinemia
  • Obesity
  • Carotid artery blockage (stenosis)
  • Family (parental) history of stroke
  • Antiphospholipid antibodies

Symptoms & Diagnosis

  • Sudden weakness or paralysis of the face, arm, and/or leg on one side of the body
  • Loss of balance, unsteady gait, dizziness
  • Acute confusion, restlessness, disorientation, drowsiness, or amnesia
  • Double vision, dimness or loss of vision in one eye
  • Severe headache, with or without vomiting
  • Numbness or abnormal sensations involving the face, arm, and/or leg on one side of the body
  • Slurred speech, loss of speech, or difficulty understanding speech

Signs of a stroke can include sudden onset of symptoms including:

  • Weakness, paralysis, or loss of sensation on one side of the body
  • Rapidly diminished vision or double vision
  • Deterioration or sudden slurring of speech
  • Loss of balance or coordination; dizziness
  • Loss of consciousness (not due to injury)
  • Severe headache

It is important to seek medical attention immediately if you experience these symptoms.

How a Stroke Is Diagnosed

The physical examination is important in making a diagnosis because it helps the physician determine the extent of impairment and neurological damage.

Laboratory Work

Blood test evaluation can include the following:

  • Complete blood count (CBC)
  • RPR (for syphilis)
  • Coagulation studies (PT, PTT)
  • Electrolytes
  • For younger patients, protein C, protein S, antithrombin III
  • Antiphospholipid antibodies

Specific Tests

Special diagnostic tests include the following:

  • Echocardiogram
  • Transthoracic echocardiogram (TTE)
  • EEG
  • Holter monitor

Imaging

  • Head CT (computer tomography) in the acute phase may be used to look for a hemorrhagic stroke
  • MRI (magnetic resonance imaging) to determine location and extent of the stroke
  • MRA (magnetic resonance angiography)
  • Carotid duplex ultrasonography
  • Cerebral angiography

Self care & Prevention

Preventing Strokes

Taking good care of your circulatory system through diet, exercise, and lifestyle changes can help prevent atherosclerosis and other factors leading to stroke.

The following measures not only help prevent stroke, they also promote good overall health and well being:

  • Control your blood pressure. High blood pressure, or hypertension, is the main risk factor for stroke because it damages the blood vessels in the brain. Keep your blood pressure in the normal range. If it's high, getting it down to a normal range can reduce your risk of stroke about 40%.
  • Control your cholesterol. High cholesterol adds to stroke risk by clogging the arteries in the brain with atherosclerotic plaque deposits. For every 1% you cut your high cholesterol, your stroke risk declines approximately 1%.
  • Don't smoke. Smoking speeds up atherosclerosis and raises blood pressure.
  • Take an aspirin a day. Its anticoagulant properties help prevent the internal blood clots that trigger most strokes. Many studies have shown that regular low-dose aspirin use prevents stroke. For instance, in one Canadian study, participants who took low-dose aspirin reduced stroke risk 31%. Ticlopidine has also been shown to have preventative effects on strokes, especially if there have been prior transient ischemic attacks (TIAs). Ask your doctor about the possibility of using one of these medications.