Stroke: The Brain’s Equivalent of a Heart Attack
Each minute that ticks by after a ]]>stroke]]> brings death to more brain tissue. The only approved treatment must be administered within a few hours of the first symptoms. Know the signs. A call for help could save a life.
Every 60 seconds, someone in the United States suffers a stroke, the equivalent in the brain of a heart attack. Men have a slightly higher risk of stroke, but women have a greater chance of dying from one. African Americans have the greatest risk, as their chances of suffering from a stroke are double that of whites.
Death of a Brain Cell
A stroke occurs when a clot forms in a blood vessel, blocking blood flow to the brain; or, less commonly, when a blood vessel in the brain ruptures and blood floods into the surrounding tissue. The first kind, responsible for 80% of attacks, is called an ischemic stroke. The second kind is called a hemorrhagic stroke. Either way, without the oxygen carried by the blood, brain cells begin to die.
"It is vital for people to recognize the signs of strokes—sudden numbness, weakness, difficulty speaking, blurred vision, dizziness, and severe headaches—and seek immediate medical attention," urges Dr. Anthony J. Furlan, medical director of the Cleveland Clinic's Cerebrovascular Center. People often wait as long as 24 to 48 hours to seek medical attention, hoping the symptoms will go away. That delay costs them dearly.
Seek immediate medical attention if you experience:
- Weakness, numbness, or tingling on one side
- Dim or blurry vision
- No vision, usually in one eye
- Inability to speak clearly
- Inability to comprehend others
- Difficulty swallowing
- Sudden falls, loss of balance
- Sudden, severe headache or a change in headache pattern
Temporary Stroke: A Big Hint
Prior to a major stroke, you may experience warning signs or what people sometimes think of as a temporary stroke. During one of these ]]>transient ischemic attacks]]> (TIAs), a clot obstructs an artery for a short time and creates symptoms similar to those of a stroke but lasts only minutes or hours. Because of the rapid recovery, people frequently dismiss the symptoms and neglect to tell anyone.
The TIA can precede a major stroke by days, weeks, or months. About one third of patients with a TIA will go on to have a stroke within five years if untreated. Of all people who had a TIA preceding their stroke, the stroke occurred within one month in 20% of the cases, and within a year in 50% of the cases. Often, prompt medical treatment after the TIA can prevent a fatal or disabling stroke.
Medications and Timing
For many years, even with the best care, little could be done to help stroke victims. Strokes became the foremost cause of long-term disability and the third leading cause of death.
Now a clot-busting, or thrombolytic, drug given within hours after the first symptoms appear can decrease brain damage caused by clots during a stroke. Tissue plasminogen activator (t-PA), commonly known as Activase, is the only stroke treatment approved by the US Food and Drug Administration (FDA). It is only used for treatment of ischemic strokes, and tests must be performed to rule out hemorrhagic stroke. Prourokinase (ProUK), another thrombolytic agent not yet approved by the FDA to treat strokes, can be given up to six hours after symptoms appear. It may be given intravenously (IV) or intra-arterially (IA). Other thrombolytic therapies are being investigated.
"When you're in a situation where the brain or nerves are without oxygen, the sooner the treatment, the better," explains Dr. Arthur L. Day of Brigham and Woman's Hospital in Boston. If the treatment is delayed significantly not only do you greatly lessen its effectiveness, but you also increase the risk of bleeding.
Another approach to treatment of strokes involves drugs that might protect brain cells from damage: neuroprotective agents. A wide variety of medications have shown promise for preventing irreversible injury to brain neurons. Some are potentially most helpful during the initial four hours after the onset of a stroke, while some might offer benefit for a slightly later period, by preventing the damage caused by the return of full blood supply to partially deprived cells (“reperfusion injury”). However, while numerous drugs have undergone study as neuroprotective agents, none have yet emerged as definitively helpful.
Prevention in High-Risk People
Anticoagulant and antiplatelet drugs are commonly used as preventive treatments for patients at high risk for having a stroke. ]]>Aspirin]]> (eg, Bayer), ]]>clopidogrel]]> (Plavix), and ]]>dipyridamole plus low-dose aspirin]]> (Aggrenox) all act to prevent clumping of blood platelets that can lead to strokes. ]]>Warfarin]]> (Coumadin) is often used in patients with ]]>atrial fibrillation]]> , as well as in other cardiac scenarios to decrease the risk of stroke.
Men at Risk
Two risk factors for stroke are currently out of our control: brain attacks occur more frequently in older adults, and the prevalence is higher in men.
"It's not entirely clear if women are protected by some process or whether men are more vulnerable," says Professor James W. Simpkins, who has been studying the effects of estrogen and brain attacks.
"We have evidence that androgens (male hormones) are bad players. They are significant in terms of providing the environment for a high incidence of stroke in men," Simpkins continues. "Testosterone (a male hormone) causes things to happen in platelets that make them more sticky. It also stimulates secretion of things in the brain that cause blood vessels to constrict."
A Host of Risk Factors
"In general, ]]>high blood pressure]]> (hypertension) is the number one risk factor. ]]>Heart disease]]> and ]]>smoking]]> are the two next most important. These are among the treatable risk factors," says Dr. Greg Albers, director of the Stanford Stroke Center in California.
Lifestyle changes and medical care can minimize stroke probability.
- Hypertension—Controlling blood pressure with diet, weight control, and medication decreases, but does not eliminate, the chance of a stroke. "Hypertension is very treatable. If you treat it, the risk of stroke comes down considerably," Albers says.
- Heart disease—Elevated cholesterol levels and hardening of the arteries are common to both heart disease and stroke.
- Damaged heart valves and irregular heart beats—In these cases, clots can form, break loose, and travel to the brain. Doctors often order medication to reduce the chance of clot formation.
- Cigarettes —"Smoking does several different things. First it causes blood to clot. Second, it promotes ]]>atherosclerosis]]> . And third, it causes small blood vessels to constrict. It's a triple whammy," Albers says. "The risk decreases substantially if you ]]>quit]]> ."
- Elevated red blood cell count—This can cause blood to clot, but is medically treatable.
- ]]>Obesity]]> and physical inactivity —Excess weight can stress the blood vessels and has a close association with high blood pressure.
- Excessive ]]>alcohol]]> intake —"If you drink heavily or binge drink, it's associated with an increased risk of stroke. It's more the quantity of the drinking," Albers explains.
Other factors that increase stroke odds include:
- Family history of stroke
- African-American, Asian-Pacific Island or Hispanic heritage
- ]]>Diabetes]]> or high blood sugar levels
- Prior stroke
Ways to Improve Your Odds
Devastating as this all sounds, your likelihood of having a severe stroke can be minimized with three simple steps:
- During your regular check up, discuss the risk factors with your doctor and develop a plan to improve your odds.
- At the first sign of trouble, call for emergency medical care.
- Don't assume symptoms will go away. The situation is as urgent as a ]]>heart attack]]> and warrants the same emergency actions.
American Heart Association
National Stroke Association
Heart and Stroke Foundation of Canada
Albers GW, Amarenco P, Easton JD, et al. Antithrombotic and thrombolytic therapy for ischemic stroke. In: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. 8th ed. Chicago, IL: The College; 2008.
Biller J, Love BB. Bradley WG, Daroff RB, Fenichel G, Jankovic J, eds. Vascular Diseases of the Nervous System—Ischemic Cerebrovascular Disease In Neurology in Clinical Practice. 4th ed. Philadelphia, PA: Elsevier; 2004: 1202-1203.
Emergency treatment for brain attack. Cleveland Clinic website. Available at: http://www.ccf.org/ .
NINDS stroke information page. National Institute of Neurological Disorders and Stroke (NINDS) website. Available at: http://www.ninds.nih.gov/disorders/stroke/stroke.htm .
Stanford Stroke Center website. Available at: http://www.stanford.edu/group/neurology/stroke/ .
¹10/23/2009 DynaMed Systematic Literature Surveillance DynaMed's Systematic Literature Surveillance : Lin HJ, Lee BC, Ho YL, et al. Postprandial glucose improves the risk prediction of cardiovascular death beyond the metabolic syndrome in the nondiabetic population. Diabetes Care. 2009;32:1721-1726.
Last reviewed January 2009 by ]]>Rimas Lukas, MD]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
Copyright © 2007 EBSCO Publishing All rights reserved.