STROKE
What Is A Stroke? A stroke occurs when a portion of the brain is damaged due to an interruption of its blood supply. This can happen in one of two ways; either an artery to the brain becomes blocked by a clot (an ischemic stroke; ischemic means poor blood supply), or the blood vessels are damaged and blood leaks out instead of reaching brain tissue (a hemorrhagic stroke). The resulting symptoms are dependent upon the part of the brain affected and the size of the damaged area. Stroke is the most common cause of brain damage in developed countries.
What Causes A Stroke? There are many potential causes for a disturbance in blood flow to the brain. Most commonly, a clot or embolus dislodges from elsewhere in the body, and ends up lodged in an artery to the brain. This happens mainly in people with atherosclerosis, a condition which causes fatty build-up and narrowing of the blood vessels, and in people with valvular heart disease. Less common causes include spasm of arteries in the brain, which closes them off; subarachnoid hemorrhage, in which a vessel in the brain with a weakened wall has ruptured; carbon monoxide poisoning; meningitis, an infection of the brain's protective covering, or decreased blood output by the heart, among others.
What Are The Risk Factors For Stroke? The risk factors for stroke are practically the same as those for heart disease / heart attacks, as all of these involve narrowed, hardened blood vessels. The major risk factors are high blood pressure, smoking, diabetes and high cholesterol. Less important, but still significant risk factors include a high-salt diet, alcohol abuse, heart disease, obesity, and family history of stroke.
What Are The Signs And Symptoms Of A Stroke? These depend greatly on which part of the brain is deprived of blood. Often, sensation is lost on one side of the body, which a person experiences as numbness, pins and needles, or clumsiness. Alternately, or in addition, one side of the body may lose its "motor" input from the brain, and movement will be impaired or impossible. Sometimes, the person will notice numbness and weakness in one arm which progresses to involve the entire side of the body over several hours. More often, the same symptoms develop more rapidly, and peak within minutes. The person may have impaired vision, and may be unable to speak clearly, or not at all. Fifty percent of people who have a stroke have previously experienced short-term events known as "transient ischemic attacks", or TIAs, which can be thought of as "mini-strokes" that resolve completely within 24 hours.
If you think someone is having a stroke, it is critical that you get the person to a hospital as quickly as possible! The severity of a stroke caused by a blood clot can be limited if "clot buster" drugs are administered early. Call 911. Do not drive if you yourself are the person involved.
With What Might A Stroke Be Confused? Several conditions can cause neurological symptoms resembling those of a stroke. For the most part, these are problems that affect only a portion of the brain: seizures, tumours, abscesses and abnormalities of blood vessel are examples. Other more generalized conditions that can resemble stroke include dementia, confusion and coma, all of which have multiple causes.
At The Hospital The medical team will ask questions to determine whether or not the person is in fact having a stroke, and if so, the extent and location of the damage. Often the person's history, risk factors, and symptoms are enough to make a diagnosis of stroke. Lab tests to aid in diagnosis include blood work to examine cholesterol levels and the ability of the blood to clot. A CT scan of the brain will be done (a special X-ray) to look directly at the brain, and the carotid arteries in the neck may be examined (e.g. by ultrasound) for narrowing and atherosclerosis.
Treatment The goals of stroke treatment are to limit brain damage, prevent complications that can occur from a long period of bed rest, and to prevent subsequent strokes. Medical staff will try to determine the exact cause of stroke, as this will determine the best preventive strategy. Early rehabilitation measures are important for recovery is to be as complete as possible.
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