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Great Hydrocephalus Sites:
Hydrocephalus Association
Their mission is to provide support, education and advocacy for individuals, families and
professionals dealing with hydrocephalus.
Website:
www.hydroassoc.org
Medline Plus
A trusted source of hydrocephalus information by the U.S. National Library of Medicine and the National Institutes of Health
www.nlm.nih.gov
Much of the material on this page comes from resources at Texas Children's
Hospital in Houston.
Website: www.texaschildrenshospital.org
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Hydrocephalus is an abnormal accumulation of cerebrospinal fluid in the ventricles of the brain. This increase in intracranial volume results in elevated
intracranial pressure and compression of the brain.
Hydrocephalus is greek for "water on the brain."
Everyone has a certain amount of cerebrospinal fluid (CSF) that flows around the brain and
inside its four spaces or ventricles inside the brain. CSF normally flows through narrow
pathways from one ventricle to the next, then over the outside of the brain and down the
spinal cord. CSF carries nutrients to the brain and helps cushion the brain inside the skull.
Some of the fluid is also absorbed by the bloodstream.
In children with spina bifida, the flow of the CSF is often blocked and CSF cannot be absorbed by
the bloodstream. As the fluid builds up, it puts pressure on the brain and increases the size of
the baby's head. In older children and adults, the head size cannot increase as the bones which
form the skull are completely joined together. If left untreated, hydrocephalus can result in brain
damage or even death.
Treatment for Hydrocephalus
Some forms of hydrocephalus require no specific treatment. Other forms are temporary and do not
require long-term treatment. However, most forms do require treatment, and this is usually done surgically.
Drugs have been used for many years but they may have unpleasant side effects and are not always successful.
The usual treatment is to insert a shunt. It is important to note that a shunt does not 'cure' the hydrocephalus,
and damage to the brain tissue remains. Shunting controls the pressure by draining excess CSF, preventing
the condition from becoming worse. Symptoms caused by elevated pressure usually improve but other problems
of brain damage can remain.
About Shunts
A shunt is a narrow plastic tube that drains the accumulated CSF from the obstructed pathways and diverts it
to the bloodstream. The device consists of a system of tubes with a valve to control the rate of drainage and prevent backflow.
This is how a shunt is implanted:
- First, some of the child's hair is shaved off, but it will grow back.
- Next, the neurosurgeon makes a small incision in the scalp and then a small
opening in the skull to place the shunt tube into one of the brain ventricles. The other
end of the shunt passes underneath the scalp behind the ear to a shunt valve called a
reservoir.
- The valve acts like a gate: it opens to let the CSF flow from the brain when the pressure
inside the brain reaches a certain level. Since the valve allows the fluid to flow in only
one direction, it prevents the fluid from flowing back into the brain.
- The fluid pools in the reservoir. Then it flows through tubing to another part of the body.
This tubing system, called a ventriculoperitoneal shunt, ends in the abdomen -- the space around
the stomach where the extra fluid is absorbed.
- Sometimes a different tubing system, called a ventriculoatrial shunt, is
used for the baby. This tubing is also attached to the shunt reservoir, but it
runs under the skin of the neck and chest into the heart, from which the CSF
flows into the bloodstream.
- Other drainage sites such as the outer lining of the lungs (called a
ventriculopleural shunt) can also be used. Your doctor will talk to you about
which type of shunt is best for your baby.
- After the operation, your child's head will be bandaged for a few days.
Once the bandage is removed, you will be able to feel the shunt tube under your
child's scalp. The device is completely enclosed so that all of it is inside
the body. You will notice a bubble. This is the reservoir and valve part of
the shunt.
In most cases, the shunts are intended to stay in place for life, although alterations or
revisions might become necessary from time to time.
Complications are usually caused either by blockage of the system or infection. They are
only occasionally due to mechanical failure of the valve. The tube or catheter also may become
too short as the individual grows and an operation to lengthen it might be necessary.
Symptoms vary enormously between individuals, but the following information gives some general
guidelines as to what to look for in shunt malfunction.
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Infant - fontanelle (soft spot) is full and bulging when baby is upright and quiet, marked scalp veins,
shunt tract has swelling/redness, vomiting, unusual tiredness, unusual irritability, seizures (abnormal twitching),
gradual head enlargement, and/or downward deviation of eyes
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Young Children - vomiting, shunt tract has swelling/redness, unusual tiredness, unusual irritability,
seizures (abnormal twitching), headache, loss of previous abilities, and/or gradual head enlargement
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Older Children/Adults - headache, nausea or vomiting, unusual tiredness, unusual irritability,
arching of head backwards, fever, difficulty with vision, personality change, loss of coordination or balance,
shunt tract has swelling/redness, difficulty in walking, seizures (abnormal twitching), and/or decline in school/work activities
Shunt blockages which are causing illness usually require an operation to replace or adjust the offending part of the shunt.
Shunt infections are usually treated by removal of the whole shunt and a course of antibiotics before insertion of a new system. Modern approaches
to antibiotic therapy mean that such treatment can be expected to succeed in most cases.
Symptoms usually develop gradually. In some cases, it shows itself in a gradual deterioration in overall performance.
Occasionally, symptoms are quite suddenly severe and may include headaches and vomiting.
Various tests can be carried out to confirm the diagnosis. Medical advice should be sought urgently
if a shunt blockage is suspected.
Shunt Infection
Symptoms vary with the route of drainage. In ventriculoperitoneal shunts, the symptoms will often resemble those
of a blockage. This is because the shunt becomes infected and the lower catheter is very often sealed off by tissue. There
may be accompanying fever and abdominal pain or discomfort. In infection of ventriculoatrial shunts, fever is present in most
cases though often intermittently. Anaemia is frequently present, sometimes skin rashes along with joint pains.
In contrast to ventriculoperitoneal shunts, such infections sometimes do not become apparent for months after the operation
at which they were contracted.
Various tests can be carried out for shunt infection and medical advice should always be sought if an infection is suspected.
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