Stroke

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Stroke is a medical emergency. Especially if you or loved ones are at risk of stroke, it is vital to know the warning signs of a stroke so that you can seek out prompt emergency medical care.

Doctors today have a range of options to draw from when tailoring treatment for patients. In the acute phase of treatment they can administer drugs that minimize damage to the brain. Clot dissolvers, such as thrombolytic agents, are most effective when used within three hours of a thrombotic or an embolic stroke. There also are new treatments in the pipeline: Clinical trials are underway on several drugs designed to protect brain tissues after a stroke occurs. Further, preliminary studies with techniques that chill the brain have shown that inducing hypothermia may reduce stroke damage.

Doctors also have at their disposal a number of medications to help ward off strokes in high-risk patients, particularly those who have experienced transient ischemic attacks (TIAs) or "ministrokes." These include anticoagulants, such as heparin or warfarin, and antiplatelet agents, including aspirin, dipyridamole, and clopidogrel.

Interventional procedures, too, can help patients with certain conditions that result from or often lead to strokes. For years, doctors "clipped" aneurysms to prevent further bleeding. However, more recently they have honed a number of more sophisticated techniques, including introducing coils into the aneurysms that can prevent rupture without the risks of brain surgery.

This section includes information on:

  • Drugs for emergency treatment of stroke
  • Medications for preventing stroke
  • Endovascular procedures
  • Carotid endarterectomy
  • Stereotactic procedures
  • Revascularization
  • Hypothermia
  • Drugs for emergency treatment of stroke

    The only FDA-approved medication for treatment of an acute ischemic stroke—the kind caused by blood clots that block blood flow to the brain—is a clot-dissolving medication known as a clotbuster. This thrombolytic agent (called tPA for "tissue plasminogen activator") is most effective if administered intravenously within the first three hours after a stroke, so it is extremely important for people experiencing symptoms to get prompt emergency treatment.

    New drugs, called neuroprotective agents, that may make the brain more resistant to damage from stroke are being tested in clinical trials at some medical centers.

    Drugs for preventing stroke

    A number of medications help ward off stroke in high-risk patients. These drugs fall into two major categories: anticoagulants or "blood thinners" (such as heparin or warfarin) and antiplatelet agents (such as aspirin, dipyridamole, and clopidogrel).

    This section has more on:

    • Anticoagulants
    • Antiplatelet agents
    • Anticoagulants

      Anticoagulants are medications that reduce the ability of the blood to clot by altering the function or production of substances that cause clots. These drugs are often used to treat deep vein thromboses and pulmonary emboli and are effective at preventing a stroke in patients with atrial fibrillation (rapid, irregular twitching of the muscles in the atria of the heart) or some other causes of cardiac embolism.

      Heparin: This anticoagulant must be injected under the skin or into a vein—it cannot be taken orally. So it is almost always used in hospitalized patients. Doctors typically prescribe it to reduce the risk of blood clots in the legs and reduce the risk of additional strokes or stroke damage in patients who have been hospitalized for specific types of stroke, such as cerebral sinus thrombosis (in which clots form in veins that drain blood from the brain).

      Warfarin: Also known by the brand name Coumadin, this anticoagulant is prescribed to prevent clots in the heart from forming or growing larger. It is taken by mouth, as a tablet. Many other medications interfere with the action of warfarin and the blood's clotting ability. Before starting the drug, you should give the doctor a list of all drugs and herbal supplements you take, and you should not start taking new drugs without first consulting with your doctor. Foods that contain vitamin K, including liver, leafy green vegetables, green tea, and cauliflower, also affect the blood's ability to clot. Patients taking Coumadin should try to avoid large variations in the amount of these foods they consume. Your doctor will monitor your response to the drug through blood tests conducted at regular intervals.

      Antiplatelet agents

      Antiplatelet agents work by preventing or reducing the occurrence of platelet aggregation of the blood. Platelet aggregation is when disklike components of the blood called platelets migrate to the site of injuries to blood vessels and stick together to form what is essentially a plug. This aggregation can sometimes result in the formation of a thrombus (blood clot) that may totally block the artery or may break loose and block a smaller artery. By preventing platelet aggregation, antiplatelet agents can reduce the risk of stroke in patients who have had transient ischemic attacks (TIAs) or ischemic strokes.

      Aspirin (acetylsalicylic acid)

      Aspirin, a common, over-the-counter pain, fever, and inflammation reducer, is also a good antiplatelet agent that can reduce the risk of stroke in patients who have experienced TIAs or ischemic strokes. Doctors will prescribe a dosage that is appropriate for each patient. Since aspirin can irritate the stomach, doctors might recommend that patients take the medication with water, milk, or food. Patients should also watch for signs of any unusual bleeding and report them to their doctor immediately.

      Dipyridamole

      Drugs like Aggrenox combine aspirin and another antiplatelet drug, dipyridamole, in one time-release pill. Dipyridamole works in a different way from aspirin to keep platelets from forming a clot. Doctors normally prescribe one pill twice a day. Some patients who take the drug develop a headache that usually subsides in several days. The drug must be swallowed whole, not broken or crushed, for it to work effectively. Patients should watch for signs of any unusual bleeding and report them to their doctor immediately.

      Clopidogrel

      Clopidogrel, also known by the brand name Plavix, is another antiplatelet agent used to help prevent the recurrence of stroke. Doctors usually prescribe one 75-mg tablet once a day. Patients should watch for signs of any unusual bleeding and report them to their doctor immediately.

      Endovascular procedures

      Doctors often recommend these relatively new surgical procedures to patients who may not be able to withstand the stresses of major surgery, whether because of advanced age or because they have other serious medical conditions. However, these procedures are appropriate for less frail patients, too. Advantages include local or regional anesthesia instead of general anesthesia, shorter recovery time, less pain, smaller incisions, and less stress on the heart. These procedures may be used to treat aneurysms, cerebral vascular malformations, and arteries that have been occluded by plaque.

      • Treatment of aneurysms: To repair an aneurysm, or a section of a vessel that has ballooned out, surgeons guide a coil (essentially, an artificial graft) into the damaged blood vessel and anchor it into place. This allows blood to flow normally again through the vessel, lowering the patient's risk of a future hemorrhagic stroke. A long plastic tube called a catheter, which has been threaded up through a tiny incision in an artery in the thigh up to the trouble spot, is used to position the coil. X-ray imaging is used to guide the catheter.
      • Treatment of cerebral vascular malformations: Endovascular surgeons may use a "superglue" substance introduced via a tiny catheter to eliminate or reduce the size of the cerebral vascular malformations. Often this facilitates further microsurgical or radiation treatment.
      • Mechanical removal of blood clots: A new tool for treating hemorrhagic stroke is a tiny device used to physically remove blood clots that are blocking blood vessels within the brain. The Food and Drug Administration recently approved one such device, the Merci Retrieval System, which works like a corkscrew to pluck out clots. In nonbleeding (ischemic) strokes, blood clots damage the brain by depriving brain cells of the oxygen and nutrients (carried in the blood) they need to survive. But when used within the first several hours after a stroke, the device can extract clots and may reduce permanent damage.
      • Angioplasty and stenting of vessels in the neck and brain: This new intervention is available at many medical centers. Cerebral angioplasty is similar to the widely used cardiology procedure, in which a tiny balloon attached to the tip of a catheter is threaded into a blocked artery and then inflated. In this case, the vessels are the carotid arteries in the neck, and a tiny tube-shaped bit of wire scaffolding, or a "stent," is inserted into the blockage to keep it open after the balloon has been withdrawn. This procedure often is offered as an alternative to carotid endarterectomy for patients for whom the more invasive surgery is thought to be too risky, whether because of the patient's overall health or because of the location of the blockage. Because angioplasty and stenting is fairly new, researchers are still investigating how well the stents hold up and how well the procedure reduces patients' risk of stroke over the long term.
      • Intra-Arterial Thrombolysis: For this procedure, doctors insert a small catheter into the blood vessels of the brain during cerebral angiography and deliver clot-dissolving medications directly to the blocked blood vessel.
      • Carotid endarterectomy

        Carotid endarterectomy is a surgical procedure used to remove atherosclerotic plaque (fatty deposits associated with cardiovascular disease) from the carotid arteries. For selected patients who have had minor strokes or transient ischemic attacks (TIAs or ministrokes), carotid endarterectomy can be highly beneficial in preventing future strokes.

        The primary factor doctors consider when weighing this procedure for an individual patient is the extent to which plaque has narrowed the affected artery ("stenosis"). For patients with less than 50 percent stenosis, the benefits of carotid endarterectomy normally do not outweigh the risks. However, in patients with 70 to 99 percent stenosis who have had recent symptoms caused by the stenosis, the surgery lowers the two-year risk of stroke by about 80 percent.

        For this procedure, patients are anesthetized. The surgeon then makes an incision in the neck at the site of the blockage. To reroute blood flow around the problem area, the surgeon may insert a tube into the artery above and below the atherosclerotic plaque. He or she then makes a lengthwise incision along the portion of the artery with the plaque, removes the plaque, and stitches the vessel closed. The surgeon then removes the tube.

        Doctors have performed these surgeries for over 40 years. In 1995, doctors in the United States performed about 132,000 carotid endarterectomies.

        Stereotactic procedures

        Stereotactic techniques, which involve placing markers on the patient's head to create reference points for very precise surgeries, allow surgeons to treat vascular malformations that were previously too difficult to reach. Stereotactic surgeries employ sophisticated computer technology in combination with MRI or CT scans to pinpoint the trouble spot. Using microscope-enhanced methods and delicate instruments, the surgeons can operate without affecting normal brain tissue.

        A nonsurgical radiosurgery technique, the CyberKnife, focuses a beam of radiation on a cerebral vascular malformation, causing it to clot and disappear. The technique, often performed on an outpatient basis, usually leaves healthy brain tissue intact.

        Revascularization

        Revascularization is a surgical technique for treating aneurysms or blocked cerebral arteries associated with atherosclerosis or moyamoya disease (a rare disease resulting in narrow or blocked vessels to the brain and irregular blood vessels). The technique essentially provides a new route of blood to the brain by grafting a blood vessel from the surface of the face near the temple to a cerebral artery through a hole in the skull.

        Hypothermia

        Preliminary studies with techniques that cool the brain or body suggest that doing so may improve outcomes for stroke patients in a variety of situations. Surgeons operating on stroke patients to correct cerebral vascular malformation and aneurysms, for instance, are finding that if they first chill the patient's brain, he or she may be less likely to suffer another stroke during the surgery. Inducing hypothermia may also give the surgeon extra time to operate.

        Studies of patients who are comatose after a cardiac arrest have shown that chilling their entire bodies improves their chances of a favorable neurological recovery. This has led other doctors to try cooling down stroke patients. As with stroke, brain injury in cardiac arrest patients is caused by the interruption of the blood flow to the brain. Currently, doctors are trying to determine how long and to what degree the body should be cooled, and whether the risks of cooling outweigh the benefits in stroke patients.

        Last reviewed on 09/15/2005

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