Stroke is one of the leading
causes of serious permanent disability
in adults and is the third leading cause of death in the country.
Ischemic
Ischemic strokes is
caused when the arteries to
the brain become narrowed or blocked, causing severely
reduced blood flow (ischemia).
Ischemic
strokes can be further divided into the following two categories:
1.
Thrombotic
A thrombotic stroke is caused when a blood clot
(thrombus) forms in one of the arteries that supply blood to the brain. A clot may be caused
by fatty deposits (plaque) that build up in arteries and cause reduced
blood flow (atherosclerosis) or other artery conditions.
2.
Embolic
An embolic stroke is
caused when a blood clot or other debris forms away from the brain,
commonly in the heart,
and is swept through the
bloodstream to lodge in narrower brain
arteries. This type of blood clot is called an embolus.
Hemorrhagic
Hemorrhagic
strokes is caused when a
blood vessel that supplies the brain ruptures and bleeds. When an
artery bleeds into the brain, brain cells and tissues do not receive
oxygen and nutrients. In addition, pressure builds up in surrounding
tissues and irritation and swelling occur, which can lead to further
brain damage.
Hemorrhagic
strokes are further divided
into the following two categories:
1. Intracerebral
An intracerebral stroke is caused by hypertension
(high blood pressure), and bleeding occurs suddenly and rapidly. There
are usually no warning signs and bleeding can be severe enough to cause
coma or death.
2. Subarachnoid
A subarachnoid stroke is caused when bleeding
occurs between the brain and the meninges in
the subarachnoid space. This type of hemorrhage is often due to an aneurysm or
an arteriovenous
malformation (AVM).
How a person recovers from a
stroke depends on the location of
the brain involved and the extent of damage done.
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