| Two million Americans lie crippled from paralyzing strokes.
After AIDS and cancer, stroke is probably the most dreaded and disabling disease to afflict Western
civilization. In the U.S., stroke is the leading cause of adult disability.
What are a person's chances of developing a stroke?
Some 730,000 Americans suffer strokes each year and 160,000 die
from them. As with heart attacks, serious and even fatal strokes can occur without warning.
Around one-fourth of victims under age 70 die from the first attack; after that the figure doubles.
Of those who survive, 40% need some degree of on-going special care, but only 10%
require institutionalization.
The remaining 60% represent the good news. Some recover completely; nearly
all improve enough to care for themselves; most are able to resume their normal activities.
What causes a stroke?
A stroke, or Cerebral Vascular Accident (CVA), is most commonly related to
atherosclerosis--a thickening, narrowing, and hardening of arteries supplying the brain with
oxygenated blood. Atherosclerosis can occur both in the arteries within the brain and in
arteries leading to the brain. The roughened, ragged inner surfaces of damaged arteries become
seedbeds for clot formation and plaque buildup. When obstruction is complete, the arteries are
said to be thrombosed. Atherosclerosis can begin
in early adolescence, and is usually found in most major arteries. Atherosclerosis is
asymptomatic and not detected by most diagnostic methods during life until it is often too late.
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In the image to the right, the
cerebral and carotid arteries are common sites of plaque buildup due to athersclerosis
and resultant strokes. |
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Sometimes pieces of plaque or a blood clot break off from other parts of the
circulatory system and travel to smaller brain arteries, producing obstruction. These are
called emboli. Some 80% of CVA's result from either thrombotic or embolic
arterial blockage.
Hemorrhages, or blowouts, cause the rest of the strokes. Most of these are
associated with uncontrolled high blood pressure which forces blood through cracks in stiffened
artery walls. A few blowouts are caused by aneurysms. Aneurysms are ballooned-out
areas in certain arteries that eventually rupture.
Aneurysms often occur in arteries at the base of the brain and in the aorta (the main heart artery).
Either way, the result is bleeding into the brain. The larger an aneurysm becomes, the more likely it is to burst.
Strokes do their damage by preventing fresh blood from reaching an area of the
brain, which soon dies from lack of oxygen. If a large portion of the brain is affected, the
stroke will be severe or fatal. A smaller area of brain damage will cause lesser symptoms.
Contact
CHIP to learn more.
"Be Healthy by Choice, Not by Chance!". |
