Stroke is a cardiovascular disease. It affects the blood vessels that supply blood to the brain. When blood flow to the brain is impaired, oxygen and important nutrients cannot be delivered. The result is abnormal brain function. Blood flow to the brain can be disrupted by either a blockage or rupture of an artery to the brain. There are many causes for a stroke. This is a medical emergency. Prompt treatment could mean the difference between life and death. Early treatment can also minimize damage to your brain and potential disability.
Stroke is the third leading cause of death and the leading cause of adult disability; only cardiovascular disease and cancer cause more deaths annually
In an ischemic stroke a blood vessel becomes blocked, usually by a blood clot and a portion of the brain becomes deprived of oxygen and will stop functioning.
Ischemic strokes account for 80% of all strokes. Rapid diagnosis and treatment of acute ischemic strokes is essential to reduce death and disability from stroke. That's why learning the FAST acronym is so important:
Small strokes may not cause any symptoms, but can still damage brain tissue. These strokes that do not cause symptoms are referred to as silent strokes. According to The U.S. National Institute of Neurological Disorders and Stroke (NINDS), these are the five major signs of stroke:
Causes
A stroke disrupts the flow of blood through your brain and damages brain tissue. There are two chief types of stroke. The most common type — ischemic stroke — results from blockage in an artery. The other type — hemorrhagic stroke — occurs when a blood vessel leaks or bursts. A transient ischemic attack (TIA) — sometimes called a ministroke — temporarily disrupts blood flow through your brain.
Ischemic stroke
Almost 90 percent of strokes are ischemic strokes. They occur when the arteries to your brain are narrowed or blocked, causing severely reduced blood flow (ischemia). Lack of blood flow deprives your brain cells of oxygen and nutrients, and cells may begin to die within minutes. The most common ischemic strokes are:
Hemorrhage is the medical term for bleeding. Hemorrhagic stroke occurs when a blood vessel in your brain leaks or ruptures. Brain hemorrhages can result from a number of conditions that affect your blood vessels, including uncontrolled high blood pressure (hypertension) and weak spots in your blood vessel walls (aneurysms). A less common cause of hemorrhage is the rupture of an arteriovenous malformation (AVM) — an abnormal tangle of thin-walled blood vessels, present at birth. There are two types of hemorrhagic stroke:
A transient ischemic attack (TIA) — sometimes called a ministroke — is a brief episode of symptoms similar to those you'd have in a stroke. The cause of a transient ischemic attack is a temporary decrease in blood supply to part of your brain. Many TIAs last less than five minutes.
Like an ischemic stroke, a TIA occurs when a clot or debris blocks blood flow to part of your brain. But unlike a stroke, which involves a more prolonged lack of blood supply and causes permanent tissue damage, a TIA doesn't leave lasting effects because the blockage is temporary.
Seek emergency care even if your symptoms seem to clear up. If you've had a TIA, it means there's likely a partially blocked or narrowed artery leading to your brain, putting you at a greater risk of a full-blown stroke that could cause permanent damage later. And it's not possible to tell if you're having a stroke or a TIA based only on your symptoms. Up to half of those whose symptoms appear to go away are actually having a stroke that's causing brain damage.
There is opportunity to use alteplase (TPA) as a clot-buster drug to dissolve the blood clot that is causing the stroke. There is a narrow window of opportunity to use this drug. The earlier that it is given, the better the result and the less potential for the complication of bleeding into the brain.
Present American Heart Association guidelines recommend that if used, TPA must be given within 4 1/2 hours after the onset of symptoms. for patients who waken from sleep with symptoms of stroke, the clock starts when they were last seen in a normal state.
TPA is injected into a vein in the arm but, the time frame for its use may be extended to six hours if it is dripped directly into the blood vessel that is blocked requiring angiography, which is performed by an interventional radiologist. Not all hospitals have access to this technology.
TPA may reverse stroke symptoms in more than one-third of patients, but may also cause bleeding in 6% patients, potentially making the stroke worse.
For posterior circulation strokes that involve the vertebrobasilar system, the time frame for treatment with TPA may be extended even further to 18 hours.
Heparin and aspirin
Drugs to thin the blood (anticoagulation; for example, heparin) are also sometimes used in treating stroke patients in the hopes of improving the patient's recovery. It is unclear, however, whether the use of anticoagulation improves the outcome from the current stroke or simply helps to prevent subsequent strokes (see below). In certain patients, aspirin given after the onset of a stroke does have a small, but measurable effect on recovery. The treating doctor will determine the medications to be used based upon a patient's specific needs.
Managing other Medical Problems
Blood pressure will be tightly controlled often using intravenous medication to prevent stroke symptoms from progressing. This is true whether the stroke is ischemic or hemorrhagic.
Supplemental oxygen is often provided.
In patients with diabetes, the blood sugar (glucose) level is often elevated after a stroke. Controlling the glucose level in these patients may minimize the size of a stroke.
Patients who have suffered a transient ischemic attacks, the patient may be discharged with blood pressure and cholesterol medications even if the blood pressure and cholesterol levels are within acceptable levels. Smoking cessation is mandatory.
Rehabilitation
When a patient is no longer acutely ill after a stroke, the health care staff focuses on maximizing the individuals functional abilities. This is most often done in an inpatient rehabilitation hospital or in a special area of a general hospital. Rehabilitation can also take place at a nursing facility.
The rehabilitation process can include some or all of the following:
Depending upon the severity of the stroke, some patients are transferred from the acute care hospital setting to a skilled nursing facility to be monitored and continue physical and occupational therapy.
Many times, home health providers can assess the home living situation and make recommendations to ease the transition home. Unfortunately, some stroke patients have such significant nursing needs that they cannot be met by relatives and friends and long-term nursing home care may be required.
REFERENCES:
del Zoppo GJ, et al. Expansion of the Time Window for Treatment of Acute Ischemic Stroke with Intravenous Tisse Plasminogen Activator: A Science Advisory from the AMerican Heart Association/American Stroke Association. Stroke 2009;40;2945-2948.
Goldtein, Larry. B. et al. Primary prevention of ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council: cosponsored by the Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group; Cardiovascular Nursing Council; Clinical Cardiology Council; Nutrition, Physical Activity, and Metabolism Council; and the Quality of Care and Outcomes Research Interdisciplinary Working Group: the American Academy of Neurology affirms the value of this guideline. Stroke. 2006 Jun;37(6):1583-633. Epub 2006 May 4.
Johnston SC. et al. National Stroke Association guidelines for the management of transient ischemic attacks. Ann Neurol. 2006 Sep;60(3):301-13.
Liferidge AT. et al. Ability of laypersons to use the Cincinnati Prehospital Stroke Scale. Prehosp Emerg Care. 2004 Oct-Dec:8(4):384-7.
Stroke is the third leading cause of death and the leading cause of adult disability; only cardiovascular disease and cancer cause more deaths annually
Types of Strokes
There are two major kinds of stroke, ischemic and hemorrhagic.In an ischemic stroke a blood vessel becomes blocked, usually by a blood clot and a portion of the brain becomes deprived of oxygen and will stop functioning.
Ischemic strokes account for 80% of all strokes. Rapid diagnosis and treatment of acute ischemic strokes is essential to reduce death and disability from stroke. That's why learning the FAST acronym is so important:
- F = Face: Is one side of the face drooping down?
- A = Arm: Can the person raise both arms, or is one arm weak?
- S = Speech: Is speech slurred or confusing?
- T = Time: Time is critical!! Call 9-1-1 immediately!
- Hemorrhagic Stroke
- A hemorrhagic stroke occurs when a blood vessel that carries oxygen and nutrients to the brain burst and spills blood into the brain. When this happens, a portion of the brain becomes deprived of oxygen and will stop functioning. Hemorrhagic stroke accounts for about 20% of strokes. The most common signs of a hemorrhagic stroke are:
- Sudden severe headache with no known cause, often described as "the worst headache of my life"
- Partial or total loss of consciousness
- Vomiting or severe nausea, when combined with other symptoms
- Sudden numbness or weakness of the face, arm or leg, especially on one side of the body
- Transient Ischemic Attacks
- Transient Ischemic Attacks (TIAs) are often called mini-strokes. The symptoms are the same as for a major stroke. In a TIA, the blood clot that is blocking the flow of blood in the brain breaks up on its own and the symptoms disappear after a short period of time. TIAs generally don't cause severe brain damage, but they are a warning sign of a future stroke and should be taken seriously. Even if symptoms disappear quickly, it is important to seek medical care immediately to prevent a future major stroke.
What are stroke symptoms?
When brain cells are deprived of oxygen, they cease to perform their usual tasks. The symptoms that follow a stroke depend on the area of the brain that has been affected and the amount of brain tissue damage.Small strokes may not cause any symptoms, but can still damage brain tissue. These strokes that do not cause symptoms are referred to as silent strokes. According to The U.S. National Institute of Neurological Disorders and Stroke (NINDS), these are the five major signs of stroke:
- Sudden numbness or weakness of the face, arm or leg, especially on one side of the body. The loss of voluntary movement and/or sensation may be complete or partial. There may an associated tingling sensation in the affected area.
- Sudden confusion or trouble speaking or understanding. Sometimes weakness in the muscles of the face can cause drooling.
- Sudden trouble seeing in one or both eyes
- Sudden trouble walking, dizziness, loss of balance or coordination
- Sudden, severe headache with no known cause
A stroke disrupts the flow of blood through your brain and damages brain tissue. There are two chief types of stroke. The most common type — ischemic stroke — results from blockage in an artery. The other type — hemorrhagic stroke — occurs when a blood vessel leaks or bursts. A transient ischemic attack (TIA) — sometimes called a ministroke — temporarily disrupts blood flow through your brain.
Ischemic stroke
Almost 90 percent of strokes are ischemic strokes. They occur when the arteries to your brain are narrowed or blocked, causing severely reduced blood flow (ischemia). Lack of blood flow deprives your brain cells of oxygen and nutrients, and cells may begin to die within minutes. The most common ischemic strokes are:
- Thrombotic stroke. This type of stroke occurs when a blood clot (thrombus) forms in one of the arteries that supply blood to your brain. A clot usually forms in areas damaged by atherosclerosis — a disease in which the arteries are clogged by fatty deposits (plaques). This process can occur within one of the two carotid (kuh-ROT-id) arteries of your neck that carry blood to your brain, as well as in other arteries of the neck or brain.
- Embolic stroke. An embolic stroke occurs when a blood clot or other debris forms in a blood vessel away from your brain — commonly in your heart — and is swept through your bloodstream to lodge in narrower brain arteries. This type of blood clot is called an embolus. It's often caused by irregular beating in the heart's two upper chambers (atrial fibrillation). This abnormal heart rhythm can lead to pooling of blood in the heart and the formation of blood clots that travel elsewhere in the body.
Hemorrhage is the medical term for bleeding. Hemorrhagic stroke occurs when a blood vessel in your brain leaks or ruptures. Brain hemorrhages can result from a number of conditions that affect your blood vessels, including uncontrolled high blood pressure (hypertension) and weak spots in your blood vessel walls (aneurysms). A less common cause of hemorrhage is the rupture of an arteriovenous malformation (AVM) — an abnormal tangle of thin-walled blood vessels, present at birth. There are two types of hemorrhagic stroke:
- Intracerebral hemorrhage. In this type of stroke, a blood vessel in the brain bursts and spills into the surrounding brain tissue, damaging cells. Brain cells beyond the leak are deprived of blood and are also damaged. High blood pressure is the most common cause of this type of hemorrhagic stroke. Over time, high blood pressure can cause small arteries inside your brain to become brittle and susceptible to cracking and rupture.
- Subarachnoid hemorrhage. In this type of stroke, bleeding starts in an artery on or near the surface of the brain and spills into the space between the surface of your brain and your skull. This bleeding is often signaled by a sudden, severe "thunderclap" headache. This type of stroke is commonly caused by the rupture of an aneurysm, which can develop with age or be present from birth. After the hemorrhage, the blood vessels in your brain may widen and narrow erratically (vasospasm), causing brain cell damage by further limiting blood flow to parts of your brain.
A transient ischemic attack (TIA) — sometimes called a ministroke — is a brief episode of symptoms similar to those you'd have in a stroke. The cause of a transient ischemic attack is a temporary decrease in blood supply to part of your brain. Many TIAs last less than five minutes.
Like an ischemic stroke, a TIA occurs when a clot or debris blocks blood flow to part of your brain. But unlike a stroke, which involves a more prolonged lack of blood supply and causes permanent tissue damage, a TIA doesn't leave lasting effects because the blockage is temporary.
Seek emergency care even if your symptoms seem to clear up. If you've had a TIA, it means there's likely a partially blocked or narrowed artery leading to your brain, putting you at a greater risk of a full-blown stroke that could cause permanent damage later. And it's not possible to tell if you're having a stroke or a TIA based only on your symptoms. Up to half of those whose symptoms appear to go away are actually having a stroke that's causing brain damage.
What is the treatment of a stroke?
Tissue plasminogen activator (TPA)There is opportunity to use alteplase (TPA) as a clot-buster drug to dissolve the blood clot that is causing the stroke. There is a narrow window of opportunity to use this drug. The earlier that it is given, the better the result and the less potential for the complication of bleeding into the brain.
Present American Heart Association guidelines recommend that if used, TPA must be given within 4 1/2 hours after the onset of symptoms. for patients who waken from sleep with symptoms of stroke, the clock starts when they were last seen in a normal state.
TPA is injected into a vein in the arm but, the time frame for its use may be extended to six hours if it is dripped directly into the blood vessel that is blocked requiring angiography, which is performed by an interventional radiologist. Not all hospitals have access to this technology.
TPA may reverse stroke symptoms in more than one-third of patients, but may also cause bleeding in 6% patients, potentially making the stroke worse.
For posterior circulation strokes that involve the vertebrobasilar system, the time frame for treatment with TPA may be extended even further to 18 hours.
Heparin and aspirin
Drugs to thin the blood (anticoagulation; for example, heparin) are also sometimes used in treating stroke patients in the hopes of improving the patient's recovery. It is unclear, however, whether the use of anticoagulation improves the outcome from the current stroke or simply helps to prevent subsequent strokes (see below). In certain patients, aspirin given after the onset of a stroke does have a small, but measurable effect on recovery. The treating doctor will determine the medications to be used based upon a patient's specific needs.
Managing other Medical Problems
Blood pressure will be tightly controlled often using intravenous medication to prevent stroke symptoms from progressing. This is true whether the stroke is ischemic or hemorrhagic.
Supplemental oxygen is often provided.
In patients with diabetes, the blood sugar (glucose) level is often elevated after a stroke. Controlling the glucose level in these patients may minimize the size of a stroke.
Patients who have suffered a transient ischemic attacks, the patient may be discharged with blood pressure and cholesterol medications even if the blood pressure and cholesterol levels are within acceptable levels. Smoking cessation is mandatory.
Rehabilitation
When a patient is no longer acutely ill after a stroke, the health care staff focuses on maximizing the individuals functional abilities. This is most often done in an inpatient rehabilitation hospital or in a special area of a general hospital. Rehabilitation can also take place at a nursing facility.
The rehabilitation process can include some or all of the following:
- speech therapy to relearn talking and swallowing;
- occupational therapy to regain as much function dexterity in the arms and hands as possible;
- physical therapy to improve strength and walking; and
- family education to orient them in caring for their loved one at home and the challenges they will face.
Depending upon the severity of the stroke, some patients are transferred from the acute care hospital setting to a skilled nursing facility to be monitored and continue physical and occupational therapy.
Many times, home health providers can assess the home living situation and make recommendations to ease the transition home. Unfortunately, some stroke patients have such significant nursing needs that they cannot be met by relatives and friends and long-term nursing home care may be required.
Preventing Strokes
Reducing Stroke Risk
All persons can take steps to reduce their risk for stroke by knowing their own risk factors for stroke and taking action to reduce those risks. Talk to your doctor about what you can do to reduce your risk for stroke.- High Blood Pressure or Hypertension (leading cause of stroke)
- Carotid or Coronary Artery Disease
- Atrial Fibrilation (Irregular Heart Beat)
- Diabetes
- Tobacco Use
- Prior Transient Ischemic Accident (TIA) or Stroke
- Elevated levels of cholesterol
- Excessive Alcohol use
- Genetics
REFERENCES:
del Zoppo GJ, et al. Expansion of the Time Window for Treatment of Acute Ischemic Stroke with Intravenous Tisse Plasminogen Activator: A Science Advisory from the AMerican Heart Association/American Stroke Association. Stroke 2009;40;2945-2948.
Goldtein, Larry. B. et al. Primary prevention of ischemic stroke: a guideline from the American Heart Association/American Stroke Association Stroke Council: cosponsored by the Atherosclerotic Peripheral Vascular Disease Interdisciplinary Working Group; Cardiovascular Nursing Council; Clinical Cardiology Council; Nutrition, Physical Activity, and Metabolism Council; and the Quality of Care and Outcomes Research Interdisciplinary Working Group: the American Academy of Neurology affirms the value of this guideline. Stroke. 2006 Jun;37(6):1583-633. Epub 2006 May 4.
Johnston SC. et al. National Stroke Association guidelines for the management of transient ischemic attacks. Ann Neurol. 2006 Sep;60(3):301-13.
Liferidge AT. et al. Ability of laypersons to use the Cincinnati Prehospital Stroke Scale. Prehosp Emerg Care. 2004 Oct-Dec:8(4):384-7.
