Saturday, October 17, 2009


What Is a Stroke?

A stroke (known medically as a cerebrovascular accident or CVA) is a sudden episode that may affect consciousness, sensation, and movement, which results from a blockage or rupture of a blood vessel in the brain. It causes symptoms that last for at least 24 hours.There are two main types -ischemic and hemorrhagic.

Ischemic Stroke

The most common type of stroke is an ischemic stroke. Up to 80 percent of stroke cases are ischemic strokes. With this stroke, not enough essential oxygen- and nutrient- rich blood is able to get to certain parts of the brain for a long enough period of time that brain tissue is damaged. This lack of blood supply occurs because a blood vessel becomes severely narrowed or blocked.

There are several reasons why a blood vessel in the brain may become severely narrowed or blocked. The two most common causes are an embolism and thrombosis.A blood vessel can also become narrowed or blocked through stenosis.

A blood clot or other tissue in the blood, such as fat or air, from a part of the body other than the brain can travel through blood vessels and become wedged in a smaller brain artery. This free-roaming clot or tissue is called an embolus (plural: emboli). Emboli often form in the heart. They also commonly form in the neck arteries or within the aorta. A stroke caused by an embolus is called an embolic stroke.
Several conditions can increase a person's chances for developing an embolus. Some of the most common include atrial fibrillation, sick sinus syndrome, and other irregular heart rhythms. These conditions can cause poor blood flow, which allows harmful clots to form. Emboli are also more likely to form in people:

A blood clot can also form in one of the brain arteries (called cerebral arteries); however, instead of breaking free, the clot remains attached to the artery wall until it grows large enough to block blood flow. This type of stroke is known as a thrombotic stroke.
Most of the time, a thrombus occurs within an area of the brain damaged by atherosclerosis. In atherosclerosis (also known as hardening of the arteries), deposits of plaque (a mixture of fatty substances, includingcholesterol and other lipids) build up along the inner walls of large- and medium-sized arteries, causing thickening, hardening, and loss of elasticity of artery walls and decreased blood flow. This increases the risk that a thrombus will form, causing severe narrowing or complete blockage of the affected blood vessel.

A third ischemic stroke cause involves a type of artery narrowing known as stenosis. This narrowing most often occurs from the buildup of plaque from atherosclerosis. Over time, this narrowing can completely block a brain artery.

Hemorrhagic Stroke

Bleeding into the brain (or the spaces surrounding the brain) causes the second main type of stroke, called a hemorrhagic stroke. In a healthy, functioning brain, cells do not come into direct contact with blood. If an artery in the brain breaks, blood moves out into the surrounding tissue, causing damage. Hemorrhagic strokes account for approximately 20 percent of all strokes.
Common hemorrhagic stroke causes include:
  • Blood vessel breakage
  • Aneurysm
  • Arteriovenous malformation
  • Trauma
  • Tumor or cancer.

Blood Vessel Breakage
Bleeding can also occur when arterial walls break open. Plaque-encrusted artery walls eventually lose their elasticity and become brittle, thin, and prone to cracking. Hypertension, commonly known as high blood pressure, increases the risk that a brittle artery wall will give way and release blood into the surrounding brain tissue. In fact, high blood pressure is the most common underlying cause of hemorrhagic stroke.

A bleeding aneurysm is a weak or thin spot on an artery wall. Over time, these weak spots stretch or balloon out under high blood pressure. The thin walls of these ballooning aneurysms can rupture and spill blood into the space surrounding brain cells.

Arteriovenous Malformation
A person with an arteriovenous malformation (AVM) also has an increased risk of hemorrhagic stroke. AVMs are a tangle of defective blood vessels and capillaries within the brain that have thin walls, which can rupture.

Any type of head trauma can cause bleeding in the brain and result in a stroke.
Tumor or Cancer
Certain types of tumors and cancer are known to cause hemorrhagic strokes. These include:

Stroke Risk Factors That You Cannot Change:

  • Growing older (the risk of stroke tends to increase with age)
  • Being male (however, women are more likely than men to die from a stroke)
  • Being African American
  • Having a family history of stroke
  • Having a history of a stroke, TIA, or heart attack.

A transient ischemic attack (TIA) is a transient stroke, or "mini-stroke" that lasts only a few minutes. A TIA occurs when the blood supply to part of the brain is briefly interrupted. TIA symptoms, which usually occur suddenly, are similar to those of stroke symptoms but do not last as long. Most symptoms of a TIA disappear within an hour, although they may persist for up to 24 hours.

Stroke Risk Factors That You Can Change or Control:

Stroke Symptoms

For a person having a stroke, the symptoms may vary depending on which part of the brain is affected. Examples of specific symptoms can include:
  • Sudden numbness or weakness of face, arm, hand, or leg (especially on one side of the body)
  • Sudden confusion
  • Sudden trouble speaking or understanding speech
  • Sudden trouble seeing in one or both eyes (such as double vision, blurred vision, or blindness)
  • Sudden dizziness, lightheadedness, or trouble walking
  • Sudden loss of balance or coordination
  • Sudden severe headache with no known cause
  • Vomiting
  • Loss of consciousness
  • Spinning sensation (vertigo)
  • Sudden collapse
  • Seizures (in a small number of cases).

There are now effective therapies for stroke that need to be administered at a hospital; however, they lose their effectiveness if they are not received within the first three hours after stroke-related symptoms appear.
Also, keep in mind that it is common for a stroke victim to protest or deny that he or she is having a stroke. If you notice a person exhibiting any of the possible symptoms of a stroke discussed above, get help right away.

Stroke Treatment

For Ischemic Stroke (Restore Blood Flow)

The main treatments used to restore blood flow to the heart involve thrombolytic drugs.
Healthcare providers may prescribe thrombolytic ("clot-busting") drugs to dissolve blood clots that are blocking blood flow to the brain. When given soon after an ischemic stroke begins, these drugs can limit or prevent permanent damage to the brain by dissolving the blood clot. In treating a stroke that has just occurred, every minute counts. Get a person who has had a stroke to the hospital as soon as possible afterstroke symptoms start so he or she may be evaluated and receive treatment as soon as possible.
A thrombolytic drug known as tissue plasminogen activator (t-PA, Activase®) can be effective for treating a stroke if a person receives it within three hours after his or her stroke symptoms have started. Because thrombolytic drugs can increase bleeding, doctors only use t-PA when they are certain that the person has suffered an ischemic stroke and not a hemorrhagic stroke.

For Hemorrhagic Stroke (Stop the Bleeding)
In people with a hemorrhagic stroke, treatment options will depend on what is causing the bleeding. The key with this type of treatment is to stop the bleeding as quickly as possible. Surgery may be one option. For example, in people with a brain aneurysm that that has bled, healthcare providers may recommend a technique called "clipping." Clipping involves clamping off the aneurysm from the blood vessel, which reduces the chance that it will burst and bleed.
The detachable coil technique is a new therapy for treating high-risk intracranial aneurysms, or aneurysms that occur inside the skull. Doctors insert a small platinum coil through an artery in the thigh and thread it through the arteries to the site of the aneurysm. They then release the coil into the aneurysm, where it triggers an immune response from the body. This immune response causes a blood clot to form inside the aneurysm, strengthening the artery walls and reducing the risk of rupture. Once the aneurysm is stabilized, a neurosurgeon can clamp it off with less risk of bleeding and death to the patient.

Medications Used for Treating a Stroke

In addition to treatments to restore blood flow in people who have suffered anischemic stroke, healthcare providers may use other medications or therapies as part of stroke treatment to reduce complications or the chances of another stroke. Some of these medicines can include:
  • Anticoagulants
  • Antiplatelets.
Anticoagulants reduce the risk of another stroke by decreasing the ability for blood to clot and also prevent existing clots from growing. These drugs are particularly useful in preventing the formation of clots in people with atrial fibrillation. The most commonly used anticoagulants for stroke treatment include warfarin (Coumadin®), heparin, and enoxaparin (Lovenox®).
Antiplatelet drugs prevent clotting by decreasing the activity of platelets, which are blood cells that help blood clot. By reducing the risk of blood clots, these drugs lower the risk of ischemic stroke. In the case of stroke treatment, doctors prescribe antiplatelet drugs mainly for prevention of another stroke. The most widely known and used antiplatelet drug is aspirin. Other antiplatelet drugs include:
  • Clopidogrel (Plavix®)
  • Ticlopidine (Ticlid®)
  • Dipyridamole (Persantine®)
  • Aspirin and dipyridamole (Aggrenox®)
  • .

The Hospital Stay

The length of your hospital stay after a stroke depends on factors such as:
  • Your condition
  • Your response to the stroke treatment
  • Tests doctors recommend to find the stroke cause.
Most people spend several days in the hospital after a stroke. While in the hospital, healthcare providers will monitor your condition, and you will receive treatment for any complications that may arise.

Treatment During the Recovery Period

Treatment for a stroke does not end when a person leaves the hospital. In fact, leaving the hospital is when treatment really begins in many cases. For a lot of people who have had a stroke, treatment is a lifelong process.
When it is time to leave the hospital, you will likely receive:
  • Specific dietary and rehabilitation instructions
  • Discharge instructions concerning driving, activity level, and medication
  • Any other restrictions.

Stroke Rehabilitation

Rehabilitation is designed to help stroke survivors become as independent as possible. It helps stroke survivors relearn the skills they lose as a result of brain damage. Another aspect of rehabilitation for stroke survivors involves teaching them how to compensate for any residual disabilities. Rehabilitation often begins 24 to 48 hours after the stroke at an acute-care hospital and may continue at inpatient, outpatient, or nursing facilities -- or at home.

Professionals Involved With Rehabilitation

Professionals involved with rehabilitation after a stroke include:
  • Physicians
  • Rehabilitation nurses
  • Physical therapists
  • Occupational therapists
  • Recreational therapists
  • Speech-language therapists
  • Vocational therapists
  • Mental health professionals.

Physicians have the primary responsibility for managing and coordinating the long-term care of stroke survivors, including recommending which rehabilitation programs will best address individual needs. Physicians are also responsible for caring for the stroke survivor's general health and providing guidance aimed at preventing a second stroke, such as:

Rehabilitation Nurses
Nurses specializing in stroke rehabilitation help survivors relearn how to carry out the basic activities of daily living. Rehabilitation nurses also educate survivors about routine healthcare, such as:
  • How to follow a medication schedule
  • How to care for the skin
  • How to manage transfers between a bed and a wheelchair
  • Special needs for people withdiabetes.
These nurses also work with survivors to reduce risk factors that may lead to a second stroke, and provide training for caregivers.
Nurses are closely involved in helping stroke survivors manage personal care issues, such as bathing and controlling incontinence. Most stroke survivors regain their ability to maintain continence, often with the help of strategies learned during rehabilitation. These strategies include strengthening pelvic muscles through special exercises and following a timed voiding schedule. If problems with incontinence continue, nurses can help caregivers learn to insert and manage catheters and to take special hygienic measures to prevent other incontinence-related health problems from developing.

Physical Therapists
Physical therapists specialize in treating disabilities related to motor and sensory impairments. They are trained in all aspects of anatomy and physiology related to normal function, with an emphasis on movement. Physical therapists can:
  • Assess the stroke survivor's strength, endurance, range of motion, gait abnormalities, and sensory deficits to design individualized rehabilitation programs aimed at regaining control over motor functions.
  • Help survivors regain the use of stroke-impaired limbs, teach compensatory strategies to reduce the effect of remaining deficits, and establish ongoing exercise programs to help people retain their newly learned skills. Disabled people tend to avoid using impaired limbs, a behavior called learned non-use. However, the repetitive use of impaired limbs encourages brain plasticity and helps reduce disabilities.
  • Encourage the use of impaired limbs. Selective sensory stimulation such as tapping or stroking, active and passive range-of-motion exercises, and temporary restraint of healthy limbs while practicing motor tasks.
  • Use a new technology, transcutaneous electrical nerve stimulation (TENS), which encourages brain reorganization and recovery of function. TENS involves using a small probe that generates an electrical current to stimulate nerve activity in stroke-impaired limbs.
In general, physical therapy emphasizes practicing:
  • Isolated movements
  • Repeatedly changing from one kind of movement to another
  • Rehearsing complex movements that require a great deal of coordination and balance, such as walking up or down stairs or moving safely between obstacles.
People who are too weak to bear their own weight can still practice repetitive movements during hydrotherapy (water provides sensory stimulation as well as weight support) or while being partially supported by a harness. A recent trend in physical therapy emphasizes the effectiveness of engaging in goal-directed activities, such as playing games, to promote coordination. Physical therapists frequently employ selective sensory stimulation to encourage use of impaired limbs and to help survivors regain awareness of stimuli on the neglected side of the body.

Occupational and Recreational Therapists

Like physical therapists, occupational therapists are concerned with improving motor and sensory abilities during rehabilitation. Occupational therapists help survivors relearn skills that are needed for performing self-directed activities, such as personal grooming, preparing meals, and housecleaning.

Occupational therapists can teach some survivors how to:
  • Adapt to driving and provide on-road training. They can teach people to divide a complex activity into its component parts, practice each part, and then perform the whole sequence of actions. This strategy can improve coordination and may help people with apraxia relearn how to carry out planned actions.
  • Develop compensatory strategies and how to change elements of their environment that limit activities of daily living. For example, people with the use of only one hand can substitute Velcro closures for buttons on clothing.
  • Make changes in their homes to increase safety, remove barriers, and facilitate physical functioning, such as installing grab bars in bathrooms.
Recreational therapists help people with a variety of disabilities to develop and use their leisure time to enhance their health, independence, and quality of life.

Speech-Language Pathologists
Speech-language pathologists can help stroke survivors with aphasia relearn how to use language or develop alternative means of communication. Speech-language pathologists can also help people improve their ability to swallow and work with patients to develop problem-solving and social skills to cope with the aftereffects of a stroke.
Many specialized therapeutic techniques have been developed to assist people with aphasia, and some forms of short-term therapy can improve comprehension rapidly.
Intensive exercises form the cornerstone of language rehabilitation. These intensive exercises can include:
  • Repeating the therapist's words
  • Practicing following directions
  • Doing reading or writing exercises.
Conversational coaching and rehearsal, as well the development of prompts or cues to help people remember specific words, are sometimes beneficial. Speech-language pathologists also help stroke survivors develop strategies for overcoming language disabilities. These strategies can include the use of symbol boards or sign language. Recent advances in computer technology have spurred the development of new types of equipment to enhance communication.
Speech-language pathologists use noninvasive imaging techniques to study swallowing patterns of stroke survivors and identify the exact source of their impairment. Difficulties with swallowing (also known as dysphagia) may be caused by several different things, including:
  • A delayed swallowing reflex
  • An inability to manipulate food with the tongue
  • An inability to detect food remaining lodged in the cheeks after swallowing.
Once they have identified the cause of the swallowing problems, speech-language pathologists will work with the individual to devise strategies to overcome or minimize the deficit. Sometimes, simply changing body position and improving posture during eating can bring about improvement. The texture of foods can be modified to make swallowing easier; for example, thin liquids, which often cause choking, can be thickened. Changing eating habits by taking small bites and chewing slowly can also help alleviate dysphagia.

Vocational Therapists
Approximately one-fourth of all strokesoccur in people between the ages of 45 and 65. For most people in this age group, returning to work is a major concern. Vocational therapists perform many of the same functions that ordinary career counselors do. They can help people:
  • With residual disabilities
  • Identify vocational strengths
  • Develop resumes that highlight those strengths
  • Identify potential employers
  • Assist in specific job searches
  • Provide referrals to stroke vocational rehabilitation agencies.
Most important, vocational therapists educate disabled individuals about their rights and protections as defined by the Americans with Disabilities Act of 1990. This law requires employers to make "reasonable accommodations" for disabled employees. Vocational therapists frequently act as mediators between employers and employees to negotiate the provision of reasonable accommodations in the workplace.

Mental Health Professionals
Addressing a stroke survivor's mental and emotional health can be an important part of stroke rehabilitation. For example, stroke survivors often experience depression (see Stroke and Depression). Treatment for such depression may shorten the rehabilitation process and lead to a more rapid recovery.
Mental health professionals that may be involved in the rehabilitation process include:
  • Psychologists
  • Psychiatrists
  • Clinical social workers.

Stroke Effects

There are many possible effects of a stroke, including paralysis, pain, and problems using or understanding language. A person who has had a stroke may also have incontinence, difficulty swallowing, and numbness. Other possible effects can involve problems with thinking and memory, as well as emotional disturbances (such as clinical depression).

Stroke Research

In the case of stroke, research currently under way includes work being done to better understand the impact of high blood pressure and other risk factors on a person's chances of having a stroke. Researchers are also studying the causes of stroke at a cellular level to find information that will help improve diagnosis, treatment, and prevention of stroke. Ongoing stroke research also includes an evaluation of constraint-induced movement therapy to improve motor function in stroke survivors.

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