Stroke is a "brain attack" causing a blockage of blood to thebrain that can lead to damage of the brain. It is like a blockedpipe under the sink that prevents water from going down thedrain. A patient who has a stroke will typically develop weakness,numbness, or speech problems. (More information about strokecan be found on the next page.)
Thrombolytic therapy is the injection of a medication—tissueplasminogen activator (tPA)—that breaks up a blood clot("clot buster"). tPA can be injected with a needle into a vein(intravenous [IV]), an artery (intra-arterial [IA]), or both(IV/IA)—one after the other. It is like liquid "Draino"for the blocked sink (figure).
Figure. Cartoon of a blocked artery in the brain that will cause a stroke if the blood clot that is blocking the blood to the brain is not removed/broken up. IV tPA travels in the blood throughout the body and can attack the blood clot. IA tPA is given through a catheter (straw) right where the clot is.
IV tPA must be given very early after a stroke by a neurologist,emergency room physician, or other physician specifically trainedin stroke. It is given within 3 hours after the first appearanceof the stroke. IA tPA can be given up to 6 hours after the strokehas occurred under x-ray guidance to the blood vessels to thebrain by a specially trained doctor. Not all hospitals havethe equipment and types of doctors needed to use IA tPA.
In this issue of Neurology, Flaherty et al.1 looked at givingIV and IA tPA together. This study describes 62 patients whocame to the hospital early enough to be treated with IV thrombolysis.The patients were first treated with IV tPA and then given IAtPA. They were evaluated after 3 months to see how well theyrecovered from their strokes.
About 35% to 50% of patients had relatively good recovery. Inother words, 3 months after their stroke, up to half of thepatients receiving IV/IA treatment were able to live their dailylives without significant problems. Patients who had severestroke symptoms at the onset of their stroke and received IV/IAhad better recovery and less long-term disability, than patientsin other studies with similarly bad strokes. Patients over theage of 80 years old had more significant disability at 3 months.This has also been seen in other studies.
What are some of the complications of this therapy?
Bleeding into the brain is the most feared complication andcan occur after IV, IA, or IV/IA administration. This occurredin one out of every 12 to 13 patients. Another complicationis death. The overall death rate after IV/IA was about 1 in6 people (18%). The death rate appeared to be higher in patientsover the age of 80-years-old (63%) compared to those less than80 years old (11%). However patients over age 80 years had moresevere strokes before treatment.
This study was not meant to say that IV/IA therapy is betterthan either IV or IA tPA alone. It does suggest that researchersshould do more studies comparing these treatments. The combinedtreatment has the benefit of early treatment with IV tPA plusmore directly attacking the "plug" in the artery with IA tPA.Another advantage of IA tPA is that it can be injected at theexact site of the blockage causing the stroke. Because of thisit may be better than IV tPA for large blood clots. As a rule,the sooner someone gets tPA after stroke symptoms start, thebetter it will work. Remember, stroke is an emergency! If youthink you might be having a stroke, get to the hospital as quicklyas you can by calling 911.
A stroke, or brain attack, is caused by the sudden loss of bloodflow to the brain or bleeding inside the head. A stroke cancause brain cells to die. This damage can cause paralysis, speechproblems, loss of feeling, memory and reasoning problems, coma,and possibly death. Fortunately, there are effective ways toprevent stroke. If you develop a stroke, seeking immediate medicalattention can help reduce your chances of death and disability.
Every year, about 750,000 people in the United States suffera stroke and about 160,000 die. Stroke is the nation's numberthree killer after heart disease and cancer. Stroke is the numberone cause of adult disability.
Call 911 immediately if you or someone you know experiencesany of the above warning signs. Jot down the time the symptomsstarted. Sometimes these warning signs last for only a few minutesand then stop. But, even if that happens or if you feel better,call 911 for help.
Risk factors for stroke that can be treated or changed
There are two types of stroke or brain attack. Ischemic strokeis caused by an interruption of blood flow to the brain. Hemorrhagicstroke is caused by bleeding inside the brain.
Eighty percent of all strokes are ischemic. Ischemic strokecan be caused by narrowing of the large arteries to the brain,also known as atherosclerosis. If a clot forms in the neck vessels,pieces can break off and block a brain blood vessel. Clots mayalso form in the heart and travel by blood flow to the brainvessels where they become lodged.
Hemorrhagic stroke is caused by the bursting of a blood vesselin the brain. It accounts for 20% of strokes. Subarachnoid hemorrhageoccurs when there are weak spots on brain arteries (aneurysms)that burst and cover the brain with blood. Blood vessels inthe brain can also burst if they are weakened by high bloodpressure, diabetes, and aging. Severe headache usually occurswith this type of stroke, as well as impaired consciousnessand vomiting.
Immediate medical care is critical for the person who is havinga stroke or brain attack. New treatments work only if givenwithin a few hours after the onset of a stroke. For example,a clot-busting drug must be given within three hours of strokeonset.
Some risk factors—age, sex, race, and a history of strokein the family—cannot be changed. However, many otherscan be controlled. Most controllable risk factors relate tothe health of the heart and blood vessels. The following canhelp prevent stroke:
Having regular medical check-ups
Controlling high blood pressure
Not smoking—stopping if you do
Treating heart disease,especially an irregular heart beat calledatrial fibrillation
Improving diet: Avoid excess fat, salt, and alcohol
Exercising
Controlling diabetes
Seeking immediate medical attentionfor warning signs of stroke
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