Hydrocephalus and Shunt Treatment
By Lisa Glickstein, Ph.D, Triplet Mom
Originally printed in March, 2006

Hydrocephalus (“water in the head”) is normally a very rare condition 
that is present at or near birth (congenital) or is acquired later in 
life, predominantly in old age as a result of brain or spinal tumor or 
stroke.  However, premature birth greatly increases the chances of this 
condition occurring, as premies are at high risk of bleeding into the 
spaces in the brain, also known as intraventricular hemorrhage (IVH).  
Therefore, our prematurely born multiples have a greater number of shunts 
than would be found in the same number of full-term children.

What is hydrocephalus?
The brain can be imagined as a large and moderately thick organ that is 
folded carefully into the skull.  It is covered with a tough membrane that 
continues down the spinal cord.  If you imagine crumpling a thick towel 
into a ball shape, you can visualize a hollow space forming in the center 
of the ball.  In the brain, this space is called the ventricles.  It is 
actually a network of larger spaces connected by narrow tubes or channels.  
The brain is kept separate from the blood in order to protect it from any 
toxic chemicals or infections that may enter the blood circulation from 
other parts of the body. However, the brain still needs nourishment and 
cushioning.  A specialized area of the brain secretes a nourishing fluid 
(called cerebrospinal – head and spine – fluid, or CSF) that then flows 
from one ventricle to the next, over the brain and around the spinal cord, 
and is then absorbed into the bloodstream through a special area of veins 
in the base of the skull.  The CSF is produced at a fairly constant rate 
and always flows in the same direction.  Anything that 1) causes more CSF 
to be produced than normal (rare), 2) prevents the veins from absorbing 
the proper amount of CSF, or 3) blocks the flow of CSF can cause it to build 
up in the ventricles.  As it builds up, it forces the brain outwards and 
presses it into the skull case.  This increase in pressure prevents the brain 
from functioning normally and, over time, can lead to permanent brain damage.

Why does hydrocephalus occur?
In infants, hydrocephalus can be caused by a malformation of the brain or 
ventricles during development.  More commonly, bleeding into the ventricles 
causes a temporary or permanent change in CSF flow.  It is easy to imagine 
that a large blood clot could block the narrow channels between ventricles.  
If the brain or lining tissue is damaged, the scars that form can also cause 
blockages, or tightening of scars will narrow the channels and impede CSF 
flow.  In older children or adults, hydrocephalus can follow a stroke, severe 
brain injury, or brain tumor.

How can you tell that hydrocephalus is occurring?
As the pressure builds up inside of the brain, it can cause a measurable 
enlargement of the skull compared to other children of the same age.  It can 
also lead to bulging of the soft spot (fontanel) of the infant skull.  The 
squeezing of the brain also leads to crying and irritability, headache, nausea 
and vomiting, blurred or double vision, seizures, or motor difficulties.  
Downward deviation of the eyes is typical in severe cases.  Some of these are 
not apparent in infants, but would be seen in older children or adults.  
Symptoms increase in severity as the pressure increases.  Head ultrasound in 
young infants, or CT/MRI scans in older babies or adults, can demonstrate the 
stretched ventricles caused by the CSF buildup.

How is hydrocephalus treated?
In infants who have had IVH, initial treatment may consist of medications or 
lumbar puncture (spinal tap) to remove fluid and reduce the intracranial 
pressure.  If the pressure rises again, or continues to be higher than normal 
after several lumbar punctures, a permanent solution must be found.  It is 
currently not possible to widen channels that may have narrowed, or to reverse 
hydrocephalus, with medication or neurosurgery.  Therefore, treatment is 
designed to give the CSF an alternate method of draining back into the body.  
In most cases, a long plastic tube called a shunt is placed under the scalp and 
skin to connect one of the ventricles to another area of the body, commonly the 
abdomen.  The CSF is produced normally in the brain and then drains through the 
shunt into the space surrounding the stomach and intestines, where it is harmlessly 
absorbed into the body.  A new surgery, known as endoscopic third ventriculostomy 
(opening a hole in the third ventricle using a specialized scope), attempts to 
create a new pathway for CSF flow.  This surgery is less often used as it is 
frequently not successful in reducing intracranial pressure, particularly in 
children under the age of two; for this reason it is usually not the primary 
treatment for hydrocephalus acquired following IVH.  Each procedure carries a 
risk of brain infection, a potentially serious outcome, particularly in the 
days to weeks immediately following the surgery.

Is the shunt permanent?
Yes, most people will require the shunt for their whole life.  It is important 
for parents and older children and adults to be alert for the signs and symptoms 
of shunt failure.  These are the same listed above for hydrocephalus prior to 
treatment.  “Revision” surgeries may be needed over time in case the shunt 
becomes clogged, infected, or to adjust the shunt for growth.  The average 
adult with a shunt has had two to three revisions in his or her lifetime.  
Some doctors are experimenting with ventriculostomy surgery in children who 
have failed shunts or shunts that require revision.

Do children with hydrocephalus develop normally?
If the intracranial pressure is reduced promptly and successfully, brain function 
is protected and development is normal.  Infants in whom treatment is delayed, or 
does not sufficiently reduce intracranial pressure, can sustain permanent brain 
damage.  This is more commonly seen in children with brain tumor, or who are 
born at term and hydrocephalus is not diagnosed promptly.  However, this is a 
rare outcome in prematurely born infants as they obtain frequent head scans in 
the NICU.  There is a higher incidence of learning disabilities in children 
with hydrocephalus, so these children are normally screened carefully during 
early childhood.

What type of doctor treats hydrocephalus?
A pediatric neurologist and neurosurgeon will manage your child’s treatment for 
hydrocephalus.  Monitoring at home for symptoms of shunt failure is important.

Where can I learn more or obtain support?
The Hydrocephalus Association (www.hydroassoc.org) offers further information and 
support.  The links page can guide you to further information, other organizations, 
online chat groups, and specialized medical centers.