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Conditions
and
Treatments of the
BRAIN
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STROKE
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A stroke occurs when the normal blood
supply to the brain is interrupted. This can happen in several ways.
A thrombosis, or blockage in a blood vessel, or an embolism, a fatty
deposit or clot which breaks loose and follows the blood stream
until it lodges in a smaller vessel, can literally cause the brain
the starve to death in a very few minutes by depriving it of blood.
The problem in these cases is too
little blood. Too much blood in the wrong place is equally perilous.
A hemorrhage, or break, in a blood vessel allows the blood to flood
the brain bringing injury - and often irreversible damage - to the
delicate structures of the brain.
Right-Hemisphere Stroke
The right hemisphere of the brain controls the movement of the left
side of the body. It also controls analytical and perceptual tasks,
such as judging distance, size, speed, or position and seeing how
parts are connected to wholes.
A stroke in the right hemisphere often causes paralysis in the left
side of the body. This is known as left hemiplegia. Survivors of
right-hemisphere strokes may also have problems with their spatial
and perceptual abilities. This may cause them to misjudge distances
(leading to a fall) or be unable to guide their hands to pick up an
object, button a shirt or tie their shoes. They may even be unable
to tell right-side up from upside-down when trying to read.
Along with their impaired ability to judge spatial relationships,
survivors of right-hemisphere strokes often have judgment
difficulties that show up in their behavioral styles. These patients
often develop an impulsive style unaware of their impairments and
certain of their ability to perform the same tasks as before the
stroke. This behavioral style can be extremely dangerous. It may
lead the left hemiplegic stroke survivor to try to walk without aid.
Or it may lead the survivor with spatial and perceptual impairments
to try to drive a car.
Survivors of right-hemisphere strokes may also experience left-sided
neglect. Stemming from visual field impairments, left-sided neglect
causes the survivor of a right-hemisphere stroke to
"forget" or "ignore" objects or people on their
left side.
Finally, some survivors of right-hemisphere strokes will experience
problems with short-term memory. Although they may be able to
recount a visit to the seashore that took place 30 years ago, they
may be unable to remember what they ate for breakfast that morning.
Left-Hemisphere Stroke
The left hemisphere of the brain controls the movement of the right
side of the body. It also controls speech and language abilities for
most people. A left-hemisphere stroke often causes paralysis of the
right side of the body. This is known as right hemiplegia.
Someone who has had a left-hemisphere stroke may also develop
aphasia. Aphasia is a catch-all term used to describe a wide range
of speech and language problems. These problems can be highly
specific, affecting only one component of the patient's ability to
communicate, such as the ability to move their speech-related
muscles to talk properly. The same patient may be completely
unimpaired when it comes to writing, reading or understanding
speech.
In contrast to survivors of right-hemisphere stroke, patients who
have had a left-hemisphere stroke often develop a slow and cautious
behavioral style. They may need frequent instruction and feedback to
complete tasks.
Finally, patients with left-hemisphere stroke may develop memory
problems similar to those of right-hemisphere stroke survivors.
These problems can include shortened retention spans, difficulty in
learning new information and problems in conceptualizing and
generalizing.
Cerebellar Stroke
The cerebellum controls many of our reflexes and much of our balance
and coordination. A stroke that takes place in the cerebellum can
cause abnormal reflexes of the head and torso, coordination and
balance problems, dizziness, nausea and vomiting.
Brain Stem Stroke
Strokes that occur in the brain stem are especially devastating. The
brain stem is the area of the brain that controls all of our
involuntary, "life-support" functions, such as breathing
rate, blood pressure and heartbeat. The brain stem also controls
abilities such as eye movements, hearing, speech and swallowing.
Since impulses generated in the brain's hemispheres must travel
through the brain stem on their way to the arms and legs, patients
with a brain stem stroke may also develop paralysis in one or both
sides of the body.
SOURCE: National
Stroke Association and NeuroSurgery.org
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