Stroke 101
Stroke can cause brain cells to die. Stroke is a serious event which occurs when blood flow to a part of the brain is suddenly interrupted. The brain normally receives 20% of the whole body's blood supply. The blood carries oxygen and nutrients which the brain needs for it to function. If oxygen supply to the brain is cut off for about 60 seconds, brain tissue ceases to function. Several hours without oxygen would lead to irreversible damage of the brain tissue, resulting in an infarct.
What is Stroke?
Stroke can cause brain cells to die. Stroke is a serious event which occurs when blood flow to a part of the brain is suddenly interrupted. The brain normally receives 20% of the whole body's blood supply. The blood carries oxygen and nutrients which the brain needs for it to function. If oxygen supply to the brain is cut off for about 60 seconds, brain tissue ceases to function. Several hours without oxygen would lead to irreversible damage of the brain tissue, resulting in an infarct.
There are two types of stroke: ischemic stroke and hemorrhagic stroke. Ischemic stroke (which comprises 80% of all strokes) is caused by an interrupted blood flow to the brain. This is usually caused by a blood clot blocking the brain blood vessel or arteries (called atherosclerosis). Hemorrhagic stroke (the remaining 20%) occurs when there is bleeding inside the brain. This usually happens when weakened blood vessels or “aneurysms” (a term for weak spots in the brain arteries) suddenly burst.
What are the symptoms of stroke?
The warning signs and symptoms of stroke are always sudden. The damage to brain tissue can cause weakness or numbness on one side of the body (face, arm, or leg); trouble seeing in one or both eyes; slurring of speech; trouble speaking, thinking or understanding; dizziness and imbalance. A hemorrhagic stroke can also cause a severe headache, vomiting, and/ or drowsiness.
The Medical City Section of Neurology devised a simple way of remembering symptoms of stroke. Just remember KAMBIO!
The following are stroke risk factors:
- Age
- High blood pressures
- Diabetes
- Cigarette smoking
- Alcohol abuse
- High level of cholesterol
- Heart disease
- Irregular heart beat (atrial fibrillation)
- Physical inactivity
- Obesity
- Family history
Stroke is an emergency
Every second counts in a stroke. Each second that blood flow to the brain is stopped could mean an irreversible amount of injury to the brain tissues. A stroke patient should therefore be managed immediately to prevent further disability.
Stroke is treatable
Timely intervention is critical for the stroke patient. In the case of ischemic strokes, a clot busting drug may be given within three hours from stroke onset. However, the patient must have arrived at the hospital within one hour of having a stroke for him/ her to be properly evaluated.
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