$Unique_ID{BRK02363}
$Pretitle{}
$Title{What Causes Strokes and What Do They Do?}
$Subject{stroke blood flow brain clot artery thrombosis wall hemorrhage supply
blockage atherosclerosis hardening arteries plaque vessels mini-stroke tia
transient ischemic attack blackout whiteout bruit carotid circulatory system
cerebrovascular accident accidents strokes clots }
$Volume{G-1}
$Log{
Sclerotic Arteries of the Brain*0002502.scf
Types of Ischemic Strokes I*0006901.scf
Types of Ischemic Strokes II*0006902.scf
Types of Hemorrhagic Strokes*0006903.scf
Atherosclerosis of Arteries*0009301.scf
Complications of Atherosclerosis*0009401.scf}

Copyright (c) 1992,1993   Tribune Media Services, Inc.


What Causes Strokes and What Do They Do?


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QUESTION:  I've just heard a story about a friend who died suddenly from a
stroke, yet I know many people who survived an episode that was diagnosed as
stroke without any ill effects.  Please clear up my confusion about strokes.
Just what happens?

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ANSWER:  Simply put, a stroke occurs when blood flow to the brain is cut off
or decreased.  This can be caused by a blood clot lodging in a brain artery
(thrombosis), or a break in the artery wall (hemorrhage).  Its after effects
can be as mild as a passing weakness or tingling in a limb or as profound as
paralysis, coma, and death.  You see, brain cells cannot store up the energy
they make from sugar and oxygen in the blood.  If their blood supply stops,
they die; and the functions they control, such as speech, muscle movement, and
reason, die with them.
     Nearly two-thirds of all strokes result from blockage due to
atherosclerosis, also called "hardening of the arteries".  Over time, a sticky
fatty substance (plaque) builds up in the lining of the blood vessels (like
corrosion in a water pipe) until the pipe either bursts or clogs up.
     About 10% of the time, a mini-stroke called a TIA (transient ischemic
attack) precedes a major stroke.  Among other things, a TIA can cause a brief
"blackout" or "whiteout" or blurred vision in one eye.  And though it doesn't
last long, one-third of all TIA victims can expect a disabling stroke within
five years.  So it's important to consult with your doctor.
     If atherosclerosis is the culprit, a swishing sound called a "bruit"
(pronounced brew-ee) may be heard when the stethoscope is applied to the
carotid arteries, located on each side of the neck.  If someone has a lot of
TIAs, more sophisticated tests will be ordered to pinpoint the narrowed
vessel.  It is possible to clean out these partially clogged arteries using
special surgical techniques.

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The material contained here is "FOR INFORMATION ONLY" and should not replace
the counsel and advice of your personal physician.  Promptly consulting your
doctor is the best path to a quick and successful resolution of any medical
problem.