02 Juli, 2010

All about "STROKE"

What is a Stroke?

Stroke, also known as a cerebrovascular accident (CVA) or a brain attack is a form of cardiovascular disease. It occurs when an artery or blood vessel supplying oxygen to the brain is either blocked by a clot or ruptures resulting in brain damage in the area of the event. Stroke has been described as a "a clinical syndrome characterized by rapidly developing clinical symptoms and/or signs of focal, and at times global, loss of cerebral function lasting more than 24 hours or leading to death with no apparent causes other than vascular origin." A similar clinical presentation typically lasting less than 24 hours but no longer than 5 minutes is called a transient ischemic attack (TIA) and is an important indicator that the person is at high risk for a stroke. According the American Heart Association, when compared with people who have not had a TIA, people who do experience a TIA are nine times more likely to go on to have a stroke at some future time.

Stroke is a medical emergency and help must be sought immediately. A person should never wait to see if the symptoms go away before calling for help. Warning signs of stroke include:

  • Sudden sensation of numbness or weakness in the face, arm, or leg, especially on one side of the body
  • Sudden difficulty speaking, a loss of fluency, or difficulty understanding speech
  • Sudden cognitive problems such as confusion, memory, attention, or problem solving
  • Sudden trouble maintaining balance
  • Sudden dizziness or difficulty walking
  • Sudden trouble seeing in one or both eyes, double vision, or blurred vision
  • Sudden, severe headache with no identifiable cause; nausea, or vomiting
  • Sudden impaired consciousness
Types of Stroke :

There are basically 2 types of stroke, hemorrhagic stroke and ischemic stroke:

Hemorrhagic Stroke

A hemorrhagic stroke is caused by a rupture of a blood vessel and may result in:

  • Subarachnoid hemorrhage, in which the blood vessel that bursts (usually due to an outpouching or aneurysm in the wall of the blood vessel) is on the brain surface and the blood hemorrhages into the space between the skull and the brain. Subarachnoid hemorrhage can cause a sudden, intense headache with neck pain, nausea, or vomiting, which may be followed by a rapid loss of consciousness or death.
  • Cerebral hemorrhage in which the blood vessel that bursts is deep in the brain and the blood hemorrhages into nearby brain tissue.

Both types of hemorrhage cause compression of brain tissue resulting in injury. The extent of compression and the amount of bleeding determine the severity of the stroke. If the hemorrhage occurs in the brainstem, it could lead to a coma or death. Many people die from hemorrhagic stroke, however, those who recover may not suffer long term damage since, when the compression eases, brain function may return. Hemorrhagic stroke accounts for 15-20% of strokes and carries a high risk of death. This type of stroke is associated with hypertension (high blood pressure), malformation of the vascular system, or disorders of blood clotting. Hemorrhagic strokes may occur at any age; the average age at occurrence is typically lower than that of ischemic stroke. Approximately 37% of patients who suffer a hemorrhagic stroke do not survive longer than 30 days.

Ischemic Stroke

Ischemic stroke accounts for approximately 85% of all strokes and is caused either by a cerebral thrombosis or cerebral embolism.

  • Cerebral thrombosis - a blood clot forms in an artery in the brain which has already been injured (typically by atherosclerosis, a fatty buildup in the walls of the artery). The interruption of the smooth flow of blood can cause a blood clot to form which then travels through the blood vessels until it blocks the flow of blood in an artery. The blockage causes cell death or injury to the surrounding brain tissue by depriving it of oxygen. According to the American Heart Association, this is the most common etiology of stroke. Cerebral thrombosis is often preceded by a TIA and tends to occur at night or early in the morning when blood pressure is low. Approximately 8-12% of patients who suffer an ischemic stroke do not survive longer than 30 days.
  • Cerebral embolism - a blood clot that forms in another part of the body, such as the heart or leg, is carried by the circulating blood until it finally lodges in an artery in the brain. The nerve cells are in that area of the brain are deprived of oxygen causing them to lose function and die within minutes. This type of clot is most typically caused by atrial fibrillation (a rhythm disorder in the atrial chamber of the heart).

Ischemic stroke tends to occur in older people above the age of 60 and the risk increases with older age. Approximately 75% of all ischemic strokes occur in people over the age of 65. It affects African-Americans more than whites; when compared with whites, young African-Americans have a 2-3 fold greater risk of experiencing an ischemic stroke. Ischemic stroke is more common in men until the age of 55, when the distribution equals between men and women.


Aftermath of Stroke

The clinical symptoms which follow a stroke are determined by the location of the clot, the function of that particular region, and the extent of damage to brain tissue. Regardless of the etiology of the stroke, hemorrhagic or ischemic, the side of the body opposite the location of the stroke is the side whose function is affected so that a stroke in the left hemisphere of the brain will affect the right side of the body and vise versa. The level of disability following the stroke ranges from mild to severe and, similarly, the impact on daily living activities can be minimal to significant.

The period immediately following a stroke is a critical one since stroke progression or recurrence is the cause of death for 90% of patients who die within the first week after a stroke. Prevention of stroke recurrence begins very soon after stroke onset since early stroke recurrence is estimated to occur in up to 8% of patients. Stroke recurrence is also estimated to be the cause of death in approximately 25% of survivors who die within the first several years after a stroke.

Comprehensive rehabilitation may improve the functional abilities of the stroke survivor, regardless of age and neurologic deficit, and decrease long-term patient care costs. Approximately 80% of stroke victims may benefit from inpatient or outpatient stroke rehabilitation. Ten percent of stroke survivors achieve complete spontaneous recovery within 8 to 12 weeks, and 10% of patients receive no benefit from any treatment. Sixteen percent of stroke survivors are institutionalized, making stroke the leading cause for admission to nursing homes or extended care facilities.


Risk Factors for Stroke

Risk factors for stroke include cardiovascular disease, metabolic conditions, and lifestyle:

  • Age - the stroke rate more than doubles for each 10 year period after the age of 55. Elderly patients have more severe strokes, higher fatality rates, and a greater percentage of patients discharged to long-term care facilities.
  • Gender - Up to the age of 55, the incidence of stroke is higher in men than women. After age 55, it is evenly distributed. Since women live longer than men, more women than men die each year of stroke.
  • Hypertension
  • Atrial fibrillation - this is thought to cause almost one half of cardioembolic strokes (clots originating in the heart).
  • Hyperhomocysteinemia - elevated levels of homocysteine are associated with poor nutritional intake in the elderly and dietary deficiency of vitamins B6, B12, and folic acid.
  • Cardiovascular disease
  • Carotid stenosis- narrowing of the carotid artery which reduced blood flow to the brain
  • Genetic conditions, such as sickle-cell disease
  • Congenital heart disease
  • Blood clotting abnormalities
  • Malformations in the veins or arteries in the brain
  • Previous stroke or TIA Social isolation
  • Diabetes
  • Hyperlipidemia (elevated lipids) or hypercholesterolemia (elevated cholesterol) in the blood
  • Obesity
  • Cigarette smoking
  • Poor diet
  • Low levels of body conditioning or physical activity
Facts about Stroke

Stroke remains one of the most serious neurologic problems in the world today. Facts regarding stroke include:

  • 700,000 new or recurrent cases of stroke occur annually in the United States, at a rate of one every 45 seconds. Approximately 500,000 are first strokes and 200,000 are second or recurrent strokes.
  • Worldwide, approximately 15 million people have a stroke each year.
  • Stroke kills more than 150,000 people per year, approximately one out of every 16 deaths.
  • Behind heart disease and cancer, stroke is the third most common cause of death in the Western world.
  • Approximately 28% of the strokes occur in patients under the age of 65.
  • Approximately 22% of men and 25% of women who suffer a stroke die within a year
  • The estimated cost of care and disability of stroke patients will be $62.7 billion in 2007, according to the World Health Organization.
  • According the National Stroke Association nearly 5 million people in the United States today have survived a stroke which translates into stroke affecting approximately 4 out of every 5 families.
  • The World Health Organization estimates that there are 15 million strokes worldwide and that high blood pressure is a major contributing factor in strokes that occur under the age of 40.

Despite gains in emergency treatments for stroke, many stroke survivors will be left with functional problems [National Heart, Lung, and Blood Institute (NHLBI) Framingham Stroke Study]:

  • 31% of stroke survivors require assistance in activities of daily living (ADL)
  • 20% of stroke survivors require assistance in mobility
  • 71% of stroke survivors who worked could not work 7 years after their strokes.

Signs and Symptoms of Stroke

Brain damage from stroke may result in a variety of signs and symptoms, including:

  • Weakness or paralysis of muscles
  • Loss or reduced muscle coordination
  • Loss of sensation
  • Loss of balance
  • Blindness in portions of the visual fields
  • Double vision or blurred vision
  • Speech problems: fluency, understanding, slurred speech, reading, writing
  • Cognitive problems: memory, attention, problem solving, calculations, confusion
  • Hemineglect (problems in paying attention to one side of the body)
  • Swallowing problems
  • Dizziness
  • Nausea and vomiting
  • Headache
  • Seizure
  • Impaired consciousness

Impairment of motor function is on the opposite side as that of the brain damage so that left hemisphere strokes affect the right side, and vice versa. Certain functions such as speech are usually affected more when the stroke occurs in the left hemisphere of the brain. The stroke patient may also experience symptoms that may be (but are not necessarily) due to the stroke itself such as fatigue, depression, insomnia, and sleep disordered breathing, and urinary incontinence.


Physiological Basis of Stroke Rehabilitation

Motor recovery usually occurs in well-described patterns after stroke. Within 48 hours of loss of movement, reflexes become more active in the involved arm and leg. As muscle tone returns, the arm and leg position themselves in resting postures known as synergy patterns.

  • Arm flexor synergy: Shoulder flexion, adduction, internal rotation; elbow flexion; wrist flexion; finger flexion
  • Arm extensor synergy: Shoulder, elbow, wrist, finger extension
  • Leg flexor synergy: Hip flexion, adduction; knee flexion; ankle dorsiflexion
  • Leg extensor synergy: Hip, knee extension; ankle plantar flexion

Voluntary movement may eventually return, and spasticity decreases with increased voluntary movement. However, muscle stretch reflexes always remain increased despite total recovery. Predictors for poor return of movement include absence of motion after 4 weeks.

Researchers are beginning to confirm the theories of motor recovery despite brain damage after stroke, which were first presented in the early 1980's. Plastic responses may occur in areas of the brain outside the damaged areas that result in partial return of lost function. Although findings such as these continue to support the need for rehabilitation services months or even years after a stroke occurs, these studies have small numbers of subjects. Large randomized clinical trials need to be completed in the future to convince the medical community that intensive rehabilitation interventions contribute to the improvement and maintenance of poststroke functional skills.


Goals of Stroke Rehabilitation

Several clinical trials have shown that rehabilitation should begin immediately after the stroke, as soon as the patient is medically stable. Basic goals of stroke rehabilitation include:

  • Preventing recurrent stroke and secondary medical complications
  • Avoiding medical complications such as deconditioning due to immobility and prolonged bed rest
  • Encouraging self-care for the patient
  • Teaching the patient to function as independently as possible in Activities of Daily Living through intensive therapy
  • Providing guidance and emotional support to the family and caregiver
  • Helping the patient and family reintegrate into the community

Progression of Stroke Rehabilitation

Rehabilitation for the stroke patients starts in the hospital as soon as the patient's medical condition has been stabilized, usually within 24-48 hours, and begins with promoting independent movement of the limbs by engaging in passive or active "range of motion" exercises. Depending on the severity of the stroke, patients then progress from sitting up to transferring to a chair to standing and bearing their own weight and then walking, with or without assistance. An important goal of this first stage of recovery is restoring functional independence by promoting self care, such as washing, brushing teeth, and taking care of personal needs.

When the patient is ready to be discharged from the hospital, depending on their functional and medical status, they may be discharged either to a rehabilitation facility, a long-term nursing facility, or to their own home for home-based or community based rehabilitation. A member of the health care team, such as a social worker, will meet with the patient and family and help them evaluate what will be most beneficial for the patients continued recovery. Regardless of which option is chosen, it is important that the patient continue to receive as intense a level of rehabilitation as they can tolerate.

The ideal level intensity for greatest efficacy of therapy has not been established, although it appears that younger stroke patients can tolerate greater amounts of exercise than older stroke patients. There is evidence that increased intensity of rehabilitation does influence outcome but attenuates over time, however, there is little understanding of this relationship and the effect on long-term functionality for stroke patients. It has been noted in various studies that greater exercise intensity has a more beneficial effect on lower limb function than for upper limbs.


Selection of a Stroke Rehabilitation Facility

There is growing evidence that the intensity level of stroke rehabilitation is correlated with outcome. Overall, intensive stroke rehabilitation is associated with significantly lower mortality, institutionalization, and dependency. In addition, studies have shown that there is a significant relationship between the intensity of rehabilitation and improvement of daily living activities, walking, and dexterity. Stroke survivors in integrated acute and rehabilitation programs make greater functional gains, are more likely remain at home, have decreased 5-year and 10-year mortality, and better quality of life than patients who are admitted to general medical units for rehabilitation. In the United States, stroke units that are characterized by coordinated interdisciplinary rehabilitation, stroke education and training, and specialized medical and nursing staff also report decreased dependency on others, less frequent institutionalization, and a lower 1-year mortality rate.

While still in acute care in the hospital, rehabilitation focuses on trying to teach the patient to move from the bed to a chair, to learn compensatory techniques that allows them to carry out activities of daily living as independently as possible (such as learning to wash with one hand), and to walk with a walker or a cane. Each of these goals must be modified to address the severity of the stroke and the immediate needs and abilities of the patient. Preventing deconditioning, which develops with prolonged immobility, is a high priority.

Patients who are too disabled to return home and need ongoing medical supervision but who have the stamina and cognitive ability to undergo intensive therapy for 3 hours a day or more usually benefit from inpatient rehabilitation units. Most patients (80%) who go through inpatient rehabilitation facilities are discharged to their homes where they continue with home-based or outpatient rehabilitation. While studies comparing inpatient rehabilitation to generalized hospital care for stroke patients clearly showed benefit for inpatient settings, a study comparing rehabilitation at an inpatient stroke unit with an intensive community-based outpatient stroke rehabilitation facility showed that functional outcomes of patients are comparable. The key in any rehabilitation unit is the intensity level and the interdisciplinary approach to rehabilitation. Clinical trials have shown a significant relationship between the intensity of rehabilitation and increased functionality for activities of daily living, walking, dexterity, and other motor deficits and cognitive deficits.

Questions that patients and families should ask about stroke rehabilitation services include:

  • What types of services are provided in the rehabilitation facility?
  • Does the rehabilitation facility provide services at the level that the patient needs? For example, is it too demanding or is it demanding enough?
  • How much therapy will be provided in the rehabilitation facility?
  • Does the program actively involve caregivers and family members?
  • Does the patient's health insurance cover rehabilitation services or the facility itself?
  • Is the patient responsible for any portion of the charges for rehabilitation services or equipment?
  • Is the facility close enough to the patient's home so that family, friends, and/or caregivers can visit easily?
  • If it is an outpatient facility, is transportation available for the patient?
  • Is the facility certified? What are the credentials of the staff?
The Stroke Rehabilitation Team

There are several health care professionals that are involved in stroke recovery and rehabilitation including:

  • Physician - to manage the medical care of the patient; may include a family internist, geriatrician, neurologist, or physiatrist (a doctor who specializes in physical medicine and rehabilitation)
  • Rehabilitation nurse - to coordinate care of the patient; provide direct care for the patient; educate the patient and family regarding relevant issues; be a liaison to the doctor
  • Physical therapist - to evaluate and treat physical disabilities through training and exercise (e.g., improving walking, teaching the patient how to get in and out of a chair, how to stand and move without losing their balance, how to walk up or down stairs, etc.). The physical therapist will also adapt aspects of therapy to suit the needs of the patient when they go home.
  • Occupational therapist - to teach patients to carry out activities of daily living that they could do before the stroke or to adapt to new ways of doing those activities if the disability makes that no longer possible - for example teaching the patient to eat, dress, or bathe using compensatory techniques so they can be as independent as possible.
  • Speech and language therapist - to help the patient with communication skills involving both understanding others as well as expressing themselves. The speech therapist will also work with the family to adapt to the communication skills of the patient. In addition, the speech therapist evaluates and treats the patient with dysphagia (swallowing difficulties).
  • Social worker - to help the patient and/or their family make decisions regarding rehabilitation facilities; arranging for support services to plan for long-term financial issues, insurance policies, future expenditures or answer questions about health insurance; provide counseling for the patient and family members who need support in coping with the new reality; and helping the patient and families plan for the return home.
  • Psychologist - to help the patient and family with mental or emotional problems they may be experiencing, and also to either work with or recommend professionals to work with the patient who may have memory or cognitive difficulties.
  • Other professionals who can address complications that may arise in the patient's treatment, such as a urologist if the patient is experiencing problems with incontinence, a psychiatrist for depression, orthotist if the patient needs special braces for legs or arms, a nutritionist if the patient is experiencing difficulties eating, or vocational counselors if the patient is able to anticipate returning to work.

The rehabilitation team should be available for the patient and their families to address any issues that arise in the course of the patient's recovery from stroke.

- A visual guide to understanding stroke

- stroke menyerang tanpa tanda-tanda yang meyakinkan


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