According to the
American Stroke Association (ASA), strokes can be classified
into two main categories:
Injury to the
brain tissue can result in many serious
physical and cognitive deficits.
How a person recovers from a stroke depends on
the area of the brain
that is involved and the extent of damage
Ischemic strokes occur when the
arteries to your brain become narrowed or blocked, causing
severely reduced blood flow (ischemia).
strokes can be further divided into the following two
commonly in your heart — and is swept through your
bloodstream to lodge in narrower brain arteries. This
type of blood clot is called an embolus.
A thrombotic stroke occurs
when a blood clot (thrombus) forms in one of the
arteries that supply blood to your 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.
An embolic stroke occurs
when a blood clot or other debris forms away from your
Hemorrhagic strokes occur 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:
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.
when bleeding occurs between the brain and the meninges
(the membrane that covers the brain) in the subarachnoid
space. This type of hemorrhage is often due to an
aneurysm or an
arteriovenous malformation (AVM).
The cerebellum is
the area of the brain that regulates all movements and
maintains balance. It coordinates movements and speech
muscles. Damage to the cerebellum can cause lack of balance
or coordination on the same side of the body. It can also
cause slurring of speech.
The left side of
the brain controls the right side of the body. Damage to the
left side of the brain can weaken or paralyze the right side
of the body, and may cause problems with speech and with the
understanding of spoken and written language.
The right side of the brain controls
the left side of the body. Damage to the right side of the
brain can weaken or paralyze the left side of the body and
may cause lack of awareness and neglect of the left side of
Transient Ischemic Attack (TIA)
is a warning
sign that can occur before a major stroke. A mini-stroke or
TIA occurs when there is a temporary interruption of blood
flow to the brain. There is no permanent damage to the
brain. The signs of a TIA are similar to those of a stroke
but they usually last less than 24 hours.
The brain stem is
a very delicate area attached to the spinal cord by thick
nerve fibers. It controls life-sustaining functions such as
breathing, blood pressure, and heart rate.
brain stem stroke that happens to this
part of the brain can cause serious impairment in
its life-sustaining functions. Symptoms of dizziness, slurred speech
and double vision are also common. It may also cause
paralysis on both sides of the body.