Stroke or "brain attack"
The origination of the term "brain
attack" and its application to stroke are credited to two
world-renowned neurologists from Canada. The National Stroke
Association began to champion the term in 1990 because it
characterizes the medical condition and communicates the actual
event more clearly to the public than does the word "stroke." The
brain is the most delicate organ in the body. In order to give the
best chance of limiting damage, brain attacks should be heeded even
more urgently than heart attacks.
Besides being the third-leading cause of death, stroke is one of
the major causes of serious disability in the United States. It can
paralyze the arms and legs and can slur speech.
What causes a stroke?
A stroke occurs when a blood vessel bringing oxygen and nutrients
to the brain bursts or is clogged by a blood clot or some other
particle. Because of this rupture or blockage, part of the brain
doesn't get the blood flow it needs. Deprived of oxygen, nerve cells
in the affected area of the brain can't function and die with
When nerve cells can't function, the part of the body controlled
by these cells can't function either. The devastating effects of
stroke are often permanent because dead brain cells aren't replaced.
As the brain controls everything we say, do and think, a stroke
can have a wide variety of effects. A stroke can affect personality,
emotions, behavior and the ability to:
Move and coordinate
temperature, pain and movement.
See or interpret what
understand, plan, reason or problem-solve.
Types of stroke
About 80 percent of strokes are ischemic. An ischemic stroke is
the result of the interruption of the flow of blood to the brain by
a blood clot. The buildup of plaque (atherosclerosis or "hardening
of the arteries") is involved in most ischemic strokes.
Doctors often refer to an ischemic stroke as being either "thrombotic"
A thrombotic stroke is caused by a blood clot (thrombus) that
forms in an artery going to the brain.
An embolic stroke occurs when a brain artery is blocked by a clot
that has formed elsewhere in the body (an embolus) and is carried
through the bloodstream to the brain. For example, a blood clot can
form in the heart and then travel through the blood vessels to the
A transient ischemic attack, known as a TIA, is a temporary
"mini-stroke." It is caused by a temporary interruption of blood
flow to the brain. The symptoms (warning signs) of a TIA are similar
to those of an ischemic stroke except that they go away in a few
minutes or hours (no more than 24 hours). A TIA is an important
warning sign that you may be at risk of having an ischemic stroke in
About 20 percent of strokes are hemorrhagic. A hemorrhagic stroke
is caused by uncontrolled bleeding in the brain. As well as
interrupting the normal flow of blood within the brain, the
uncontrolled bleeding "floods" and kills brain cells. High blood
pressure increases the risk of hemorrhagic stroke.
There are two main types of hemorrhagic stroke: subarachnoid
hemorrhages and intracerebral hemorrhages.
A subarachnoid hemorrhage occurs when there is uncontrolled
bleeding on the surface of the brain, in the area between the brain
and the skull.
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