Stroke
medical conditions

Stroke

Explore the available health information, treatment context, and integrative evidence for Stroke.

Background
  • A stroke (or cerebrovascular accident, CVA) is much like what a heart attack is to the heart, but to the brain. A stroke involves the sudden interruption of blood flow and oxygen to areas in the brain and can cause brain damage and loss of function. Stroke develops suddenly, usually in a matter of minutes, and causes symptoms such as paralysis, numbness or weakness often affecting one side of the body, confusion, dizziness, speech problems, and loss of vision. How a stroke patient is affected depends on where the stroke occurs in the brain and how much the brain is damaged.
  • There are two main types of strokes: ischemic and hemorrhagic. Ischemic strokes are by far the more common type, and occur when a blood clot or plaque (protein, cholesterol, and material) deposit blocks an artery supplying blood to the brain. A hemorrhagic stroke occurs when an artery in the brain bursts, causing blood to flow into the surrounding tissue. The mortality rate is higher for hemorrhagic stroke than for ischemic stroke, with most deaths occurring within the first 48 hours of the event.
  • A transient ischemic attack (TIA) is a type of stroke that usually lasts only 10 - 20 minutes. TIAs are sometimes considered to be "mini-strokes." While TIAs cause no long-term damage, having a TIA puts an individual at increased risk of acute stroke. Symptoms of TIAs may go unnoticed, and may be confused with other conditions such as epilepsy, migraines, or diabetes.
  • Stroke is a medical emergency. Prompt treatment of a stroke could be the difference between life and death. Early treatment can also minimize damage to the brain and potential disability.
  • The National Stroke Association reports that in the United States, stroke is a leading cause of adult disability and the third-leading cause of death. Only heart disease and cancer cause more deaths annually.
  • Men are 1.25 times more likely to suffer from strokes than women, yet 60% of deaths from stroke occur in women.
  • Eighty percent of strokes are preventable, which would save approximately 600,000 Americans annually.
Risk Factors and Causes
  • Age: A stroke can happen to anyone, but the risk of stroke increases with age. After the age of 55, the risk of stroke doubles for every ten years (decade).
  • Gender: Stroke is more common in men than women, but more women than men die from stroke. Women tend to be older than men when a stroke occurs and are less likely to recover due to age and fragility. Also, use of hormonal replacement therapy (HRT), birth control pills, and pregnancy can increase the risk of stroke in women.
  • Race: African American individuals are at an risk of stroke almost double that of Caucasians. Hispanics or Asian/Pacific Islanders also have a higher risk of stroke than Caucasians.
  • Family history: If a relative in a patient's immediate family, such as a parent or sibling, has had a stroke, a patient's risk of stroke is increased.
  • Previous stroke or TIA: A prior stroke or a transient ischemic attack (ministroke) increases the chances of another stroke within five years by approximately 25-40%.
  • High blood pressure (hypertension): High blood pressure is a risk factor for both ischemic and hemorrhagic strokes. It can weaken and damage blood vessels in and around the brain, leaving them vulnerable to atherosclerosis (hardening of the arteries) and hemorrhage. High blood pressure increases stroke risk four to six times, and is the most common cause of stroke
  • High cholesterol: High cholesterol levels, especially low-density lipoprotein (LDL) cholesterol (the "bad" cholesterol), may increase the risk of atherosclerosis. In excess, LDLs and other materials build up on the lining of artery walls, where they may harden into plaques. The blood must now force it's way through tiny openings, if any opening at all. When the blood flow is completely blocked, a lack of oxygen causes cells to die and may cause a stroke in the brain.
  • Smoking: Cigarette smoking places an individual at a much higher risk of stroke than nonsmokers. Smoking contributes to plaques in arteries. Nicotine makes the heart work harder by increasing heart rate and blood pressure. The carbon monoxide in cigarette smoke replaces oxygen in the blood (called hypoxia), decreasing the amount of oxygen delivered to the brain and the rest of the body.
  • Diabetes: Diabetes is a major risk factor for stroke. People with diabetes are at increased risk of stroke because diabetes may damage arteries, predisposing them to atherosclerosis (hardening of the arteries). Overall, the risk of cardiovascular disease (including stroke) is two-and-a-half times higher in men and women with diabetes compared to people without diabetes.
  • Obesity: A high body mass index (BMI), or the amount of fat on the body, increases the chances of developing high blood pressure, heart disease, atherosclerosis and diabetes, all of which increase risk factors associated with stroke.
  • Cardiovascular disease: Cardiovascular diseases, or coronary heart disease (CAD), can increase the risk of a stroke. Coronary heart diseases include congestive heart failure, a previous heart attack, an infection of a heart valve (endocarditis), a particular type of abnormal heart rhythm (atrial fibrillation or AF), aortic or mitral valve disease, valve replacement, or a hole in the upper chambers of the heart (patent foramen ovale). AF increases stroke risk up to six times, because the abnormal pumping of the heart allows blood to pool within the chamber and form clots, which are then pumped into the bloodstream and travel throughout the body and potentially into the brain. About 15% of all people who have a stroke have AF. Additionally, atherosclerosis in blood vessels around the heart may indicate atherosclerosis in other blood vessels - including those in and around the brain.
  • Elevated homocysteine levels: The amino acid homocysteine occurs naturally in the body. Elevated levels of homocysteine have been linked with a high risk of coronary heart disease and stroke. Homocysteine stimulates the growth of cells that help form plaque (deposits of protein and cholesterol) in blood vessels, encouraging blood clotting and blockages in the vessels.
  • Birth control pills and hormone therapy: The risk of stroke is higher among women who take birth control pills (oral contraception), especially among smokers and those older than 35. Lower dosages may help decrease the risk of stroke. Hormone replacement therapy (HRT) used during menopause also carries an increased risk of stroke.
  • Sickle cell anemia: Sickle cell anemia, which can cause blood cells to clump up and block blood vessels, also increases stroke risk. Stroke is the second leading killer of people under 20 who suffer from sickle-cell anemia.
  • Others: Hypercoagulable (increase in blood clotting) conditions such as Factor V Leiden (the most common), prothrombin gene mutation (a hereditary condition), elevated levels of fibrinogen (a protein involved in clotting), deficiencies of natural proteins that prevent clotting (called anticoagulant proteins - such as antithrombin, protein C and protein S), and "sticky" platelets (easily clump together) increase the risk of stroke. Heavy or binge drinking (drinking more than 2 drinks per day may increase stroke risk by 50%), the use of illicit drugs such as cocaine and methamphetamine, some prescription stimulant drugs (amphetamines), and uncontrolled stress can also increase the risk of stroke.
Signs and Symptoms
  • Signs and symptoms of a stroke include sudden numbness or weakness of the face, arm or leg, especially on one side of the body, sudden confusion, trouble speaking or understanding, sudden trouble seeing in one or both eyes, sudden difficulty walking, dizziness, loss of balance or coordination, and sudden, severe headache with no known cause.
  • For most people, stroke has no warning. One possible indicator of a future stroke is a transient ischemic attack (TIA). A TIA is a temporary interruption of blood flow to some part of the brain. TIA signs and symptoms are similar to stroke, but last for a shorter period of time (usually several minutes to 24 hours), and then disappear with no apparent permanent effects. Individuals who have had a TIA are at a very high risk of having a stroke.
Diagnosis
  • Physical examination and tests: Risk factors of stroke are evaluated, including high blood pressure, high cholesterol levels, diabetes, medications, elevated levels of homocysteine, and obesity. Stroke symptoms are documented after the occurrence, often using scoring systems such as the National Institutes of Health Stroke Scale, the Cincinnati Stroke Scale, and the Los Angeles Prehospital Stroke Screen. These tests ask medical history questions and measure left and right paralysis (loss of muscle control and movement). The latter is used by emergency medical technicians (EMTs) to determine whether a patient needs transport to a stroke center (a hospital specializing in stroke).
  • Carotid ultrasonography: This procedure evaluates blood flow using a wand-like device (transducer) that sends high-frequency sound waves into the neck. Narrowing or clotting in the carotid arteries can be determined.
  • Arteriography: Arteriography views arteries in the brain not normally able to be seen in X-rays. During this procedure, a thin, flexible tube (catheter) is inserted through a small incision, usually in the groin area. The catheter is manipulated through the major arteries and into the carotid or vertebral artery. A dye is then injected through the catheter to provide X-ray images of the arteries.
  • Computerized tomography angiography (CTA): In computerized tomographic angiography (CTA), a dye is injected into the blood and X-ray beams create a three-dimensional image of the blood vessels in the neck and brain. CTA is used to look for aneurysms (weakened or ruptured blood vessel) or arteriovenous malformations (masses of abnormal blood vessels growing in the brain) and to evaluate arteries for narrowing. CT scanning, which is done without dye, can provide images of the brain and show hemorrhages, but without as much detailed information about the blood vessels.
  • Magnetic resonance imaging (MRI): An MRI uses a strong magnetic field to generate a three-dimensional view of the brain. This test is sensitive for detecting an area of brain tissue damaged by an ischemic stroke. Magnetic resonance angiography (MRA) uses this magnetic field and a dye injected into the veins to evaluate arteries in the neck and brain.
Complications
  • A stroke may cause physical or behavioral changes in an individual. Physical changes are dependent on the side and part of the brain affected by the stroke. Stroke may affect the ability to process language, reading, articulation (ability to enunciate words), or even the ability to swallow. Behavioral changes can include depression and other mental illnesses.
  • Right brain: Different sides of the brain control opposite sides of the body. Therefore, a stroke affecting one side will result in neurological (nervous system or nerve) complications on the side of the body if affects. For example, if the stroke occurs in the brain's right side, the left side of the body will be affected. The symptoms include paralysis on the left side of the body, vision problems, quick, inquisitive behavioral style, and memory loss.
  • Left brain: If the stroke occurs in the left side of the brain, the right side of the body (and the left side of the face) will be affected, producing effects including paralysis on the right side of the body, speech/language problems, slow, cautious behavioral style, and memory loss.
Treatment
  • The earlier the treatment is received, the higher the chance of survival and recovery. It is imperative to seek medical attention immediately if a stroke is suspected. Helping identify a stroke victim includes asking the individual to smile, to raise both arms and keep them raised, or to speak a simple sentence (coherently).
  • Guidelines for stroke prevention have been developed by the American Heart Association. Primary prevention focuses on preventing a stroke, while secondary prevention focuses on preventing stroke in those with a history of stroke or TIA.
  • Ischemic stroke :
  • Emergency treatment for an ischemic stroke depends on the location and cause of the clot. Measures are taken to stabilize vital signs, including intravenous (into the veins) fluids and medications such as clot dissolving drugs and anti-platelet drugs.
  • Tissue plasminogen activator (tPA): If the stroke is diagnosed within three hours of the start of symptoms, a clot-dissolving medication called tissue plasminogen activator (t-PA) is usually given, which may increase the chance of survival and recovery. Tissue plasminogen activator is not safe for hemorrhagic stroke (bleeding in the brain), as use of t-PA would be life-threatening by increasing bleeding.
  • Anti-platelet drugs: Platelets are cells in the blood that initiate clot formation. Anti-platelet drugs make the platelets less sticky and are therefore less likely to clump (aggregate) and form clots. The most frequently used anti-platelet medication is over the counter aspirin in doses of 81 to 325 milligrams daily. Aggrenox®, a prescription combination product of low-dose aspirin and the anti-platelet agent dipyridamole, may also be used to reduce blood clotting. Other anti-platelet drugs, such as clopidogrel (Plavix®) or ticlopidine (Ticlid®) may also be utilized. The drugs may be used in combination. However, initiation of these therapies are not recommended within 24 hours of treatment with t-PA due to an increase in serious bleeding problems. Side effects include increased risk of bleeding. There are many possible drug and supplement interactions while taking anti-platelet therapy.
  • Anticoagulants: Anticoagulation treatments slow the time that it takes for the blood to clot. The drugs used in this class include heparin and warfarin (Coumadin®). They affect the mechanism of clotting differently than anti-platelet medications. Heparin, an injection, is a fast acting agent and is used short-term in the hospital, while warfarin, taken by mouth, acts more slowly and is used over a longer term. These drugs have a profound effect on blood clotting and require that the patient work closely with their provider to ensure that they are within therapeutic range as well as to reduce the risk of adverse bleeding events. As with the anti-platelet medications, there are many possible drug and supplement interactions while taking anticoagulant therapy.
  • Biological therapy: Biologic therapy treats the immune system. The use of abciximab (ReoPro®) in acute stroke is being studied. This injectable drug has anti-platelet activity and must be used within six hours of stroke.
  • Other medications: Other medications may be given to control blood sugar levels (such as oral blood sugar lowering drugs), fever (including acetaminophen or Tylenol®), and seizures (such as anticonvulsant drugs). In general, high blood pressure is not treated immediately unless systolic pressure is greater than 220 millimeters of mercury (mmHg) and diastolic is more than 120 mmHg (reading as 220/120 mmHg).
  • Surgical and other procedures: Procedures to open up the artery that has been moderately to severely narrowed by plaque (deposits of cholesterol and protein in the blood) may be necessary. These include carotid endarterectomy and angioplasty.
  • Carotid endarterectomy: After a stroke has occurred, an incision in the neck is made to expose the carotid artery. The artery is opened and the plaques are removed, thereby reducing the risk of ischemic stroke. However, in addition to the usual risks associated with any surgery, a carotid endarterectomy itself can also trigger a stroke or heart attack by releasing a blood clot or fatty debris in blood vessels in the brain. As a standard practice, surgeons now place filters at strategic points in the bloodstream to "catch" any material that may break free during the procedure, preventing it from traveling to the heart or brain.
  • Angioplasty: Angioplasty widens the inside of an artery leading to the brain (usually the carotid artery). During this procedure, a balloon-tipped catheter is maneuvered into the obstructed area of the suspected artery. The balloon is inflated, compressing the plaques against the artery walls. A metallic mesh tube (stent) is usually left inside the artery following the procedure to prevent recurrent narrowing. Stents can stay in for many years, but occasionally must be replaced. Anticoagulant drugs such as aspirin and/or clopidogrel (Plavix®) are commonly used after stent placement.
  • Hemorrhagic stroke :
  • Surgery may be used to treat a hemorrhagic stroke or prevent recurrence. The most common procedures include aneurysm (weakened or ruptured blood vessel) clipping and arteriovenous malformation (AVM) (masses of abnormal blood vessels growing in the brain) removal, and both surgeries carry high risks such as an increase in bleeding and damage to the brain, causing long-term complications such as paralysis (loss of muscle control and use) and behavioral changes.
  • Surgical AVM removal: Surgical removal of a smaller AVM from a more accessible portion of the brain can eliminate the risk of rupture, lowering the overall risk of hemorrhagic stroke. Other treatment options for AVMs include radiation or embolization, in which the small arteries supplying the blood to the AVM are blocked with clamps, shrinking the AVM and reducing the chances of rupture.
  • Aneurysm clipping: A tiny clamp is placed at the base of the aneurysm, isolating it from the circulation of the artery. The clamp is attached to the vessels to keep it from bursting (rupturing) or bleeding.
  • Coiling: During coil embolization, tiny, soft platinum coils are placed within a bulging brain aneurysm in order to relieve pressure from circulating blood on the walls of the aneurysm and to prevent rupture. The coils are guided to the aneurysm through the use of a catheter inserted into the femoral artery at the groin. Through the use of precision radiologic monitors, and 3D imaging, the coils are advanced to the aneurysm.
  • Recovery and rehabilitation: Stroke rehabilitation (for both ischemic and hemorrhagic stroke) is the process by which patients with stroke-induced disabilities undergo treatment to help them regain and relearn the skills necessary for everyday living. It also aims to help the survivor understand and adapt to difficulties such as speech and movement, prevent secondary complications, and educate family members to play a supporting role. Following a stroke, the period of recovery and rehabilitation necessary varies between patients depending on the area of the brain involved and the amount of tissue damaged. Harm to the right side of the brain may impair movement and sensation on the left side of the body. Damage to brain tissue on the left side may affect movement on the right side; this damage may also cause speech and language disorders. In addition, individuals who have experienced a stroke may experience problems with breathing, swallowing, balancing and hearing, and loss of vision, bladder or bowel function. Recovery may take years. Some may recover in full, while others may not progress at all. This depends on each individual and the extent of the stroke damage.
References

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

  • American Stroke Association. . Accessed April 29, 2009.
  • National Institutes of Health. . Accessed April 29, 2009.
  • National Institute of Neurological Disorders and Stroke. . Accessed April 29, 2009.
  • National Stroke Association. . Accessed April 29, 2009.
  • Natural Standard: The Authority on Integrative Medicine. . Copyright © 2009. Accessed April 29, 2009.
  • Society for Interventional Radiology. . Accessed April 29, 2009.