A stroke occurs when the blood supply to part of the brain is suddenly blocked or when a blood vessel in the brain bursts, spilling blood into the spaces surrounding brain cells. In the same way that a person suffering a loss of blood flow to the heart is said to be having a heart attack, a person with a loss of blood flow to the brain or sudden bleeding in the brain can be said to be having a "brain attack."
Paralysis is a common feature of stroke, often on one side of the body (hemiplegia). The paralysis or weakness may affect only the face, an arm, or a leg or may affect one entire side of the body and face.
A person who suffers a stroke in the left hemisphere of the brain will show right-sided paralysis or paresis. Conversely, a person with a stroke in the right hemisphere of the brain will show deficits on the left side of the body.
Ischemia is the term used to describe the loss of oxygen and nutrients for brain cells when there is inadequate blood flow. Ischemia ultimately leads to infarction, the death of brain cells, which are eventually replaced by a fluid-filled cavity (or infarct) in the injured brain.
When blood flow to the brain is interrupted, some brain cells die immediately; others remain at risk for death. The damaged cells can be saved by early intervention with drugs. Researchers have learned that restoring blood flow to these cells can be achieved by administrating the clot-dissolving agent tissue plasminogen activator (t-PA) within 3 hours of the start of the stroke. Many neuroprotective drugs are being tested to prevent the wave of damage after the initial attack.
Stroke has always been viewed as unpreventable and untreatable. Added to this fatalism was the wrong belief that stroke happens only to the elderly and is therefore not of concern.
As a result of these misconceptions, the average stroke patient waits more than 12 hours before arriving at the emergency room. Health care providers take an attitude of "watchful waiting" instead of treating stroke as a medical emergency.
With the use of the term "brain attack," stroke has a definitive, descriptive name. The appropriate response to a brain attack is emergency action, both by the person it strikes and the medical community. Educating the public to treat stroke as a brain attack and to seek emergency treatment is crucial because every minute lost, from the onset of symptoms to the time of emergency contact, cuts into the limited window of opportunity for intervention.
The symptoms of a stroke are easy to spot: sudden numbness or weakness, especially on one side of the body; sudden confusion or trouble speaking or understanding speech; sudden trouble seeing in one or both eyes; sudden trouble walking, dizziness, or loss of balance or coordination; or sudden severe headache with no known cause. Stroke can usually be distinguished from other causes of dizziness or headache. These symptoms may indicate that a stroke has occurred and that medical attention is needed immediately.
The most important risk factors for stroke are hypertension, heart disease, diabetes, and cigarette smoking. Others include heavy alcohol consumption, high blood cholesterol levels, illicit drug use, and genetic or congenital conditions, particularly vascular abnormalities.
In ways not clearly understood, the brain compensates for the damage caused by stroke or brain attack. Some brain cells may be only temporarily damaged, not killed, and may resume functioning. In some cases, the brain can reorganize its own functioning. Sometimes, a region of the brain takes over for a region damaged by the stroke. Stroke survivors sometimes experience remarkable and unanticipated recoveries that can't be explained.
General recovery guidelines show:
* 10 percent of stroke survivors recover almost completely
* 25 percent recover with minor impairments
* 40 percent experience moderate to severe impairments requiring special care
* 10 percent require care in a nursing home or other long-term care facility
* 15 percent die shortly after the stroke
Rehabilitation starts in the hospital as soon as possible after the stroke. In patients who are stable, rehabilitation may begin within two days after the stroke has occurred, and should be continued as necessary after release from the hospital. Rehabilitation options may include the rehab unit of a hospital, a subacute care unit, a rehab hospital, home therapy, outpatient care, or long term care in a nursing facility.
The goal in rehabilitation is to improve function so that the stroke survivor can become as independent as possible. This must be accomplished in a way that preserves dignity while motivating the survivor to relearn basic skills the stroke may have taken away – such as eating, dressing and walking.
Although stroke is a disease of the brain, it can affect the entire body. Some of the disabilities that can result from a stroke include paralysis, cognitive deficits, speech problems, emotional difficulties, daily living problems, and pain.
Stroke may cause problems with thinking, awareness, attention, learning, judgment, and memory. A stroke patient may be unaware of his or her surroundings, or may be unaware of the mental deficits that resulted from the stroke.
Stroke victims often have problems understanding or forming speech. Language problems usually result from damage to the left temporal and parietal lobes of the brain.
A stroke can lead to emotional problems. Stroke patients may have difficulty controlling their emotions or may express inappropriate emotions in certain situations. One common disability that occurs with many stroke patients is depression -- more than a general sadness resulting from the stroke incident.
Stroke patients may experience pain, uncomfortable numbness, or strange sensations after a stroke. These sensations may be due to many factors including damage to the sensory regions of the brain, stiff joints, or a disabled limb.
According to the National Stroke Association, the total cost of stroke to the United States is about $43 billion a year, with direct costs for medical care and therapy estimated at about $28 billion a year.
Sources: National Stroke Association, National Institute of Neurological Disorders and Stroke.