Hydrocephalus is a brain
condition that happens when cerebrospinal fluid (CSF) — the clear, watery fluid
that surrounds and cushions the brain and spinal cord — can't drain from the
brain. It then pools, causing a buildup of fluid in the skull.
Hydrocephalus (also called "water on the brain") can make babies' and young children's
heads swell to make room for the excess fluid. Older kids, whose skull bones have
matured and fused together, have painful headaches from the increased pressure in
If it's not treated, hydrocephalus can lead to brain damage, a loss in mental and
physical abilities, and even death. With early diagnosis and timely treatment, though,
most children recover successfully.
What Causes Hydrocephalus?
When everything is working normally, CSF flows through a series of cavities (called
ventricles) and narrow channels until it leaves the brain to fill the skull and spine.
The brain and the spinal cord float in it. Then CSF is recycled into the bloodstream.
If there's a blockage in any of the ventricles, or something disturbs the recycling,
CSF backs up and causes hydrocephalus.
Hydrocephalus can be congenital or acquired:
Congenital hydrocephalus means a baby is born with the condition.
This is often due to problems like spina
bifida (abnormal development of the spinal cord) or aqueductal stenosis (the narrowing
of a small passageway, the "aqueduct of Sylvius," that connects two major ventricles
in the brain).
Acquired hydrocephalus happens after birth and can affect people
of any age. It's usually caused by bleeding in the brain. This can happen in premature
babies or people who've had traumatic head
injuries. Some kids can develop hydrocephalus due to a tumor
or infection in the brain. Sometimes, the cause is not known.
What Are the Signs & Symptoms of Hydrocephalus?
Signs in Babies
Symptoms of hydrocephalus can vary depending on the age of a child.
Babies under the age of 1 year will have heads that appear very swollen. Their
skull bones — thin, bony plates that haven't yet fused together — are
connected by fibrous tissue called sutures. These sutures, or "soft spots," haven't
hardened yet, and stretch and expand to store the excess CSF. As a result, a baby
with hydrocephalus will appear to have an oddly shaped head — usually much larger
than other babies the same age.
Other signs to look for include:
bulging at the soft spots
"split" sutures — a gap can be felt between skull bones
rapid increase in head circumference
swollen veins that are easily seen with the naked eye
downward cast of the eyes (called "sunsetting")
Depending on how severe the condition is, babies also may seem excessively sleepy,
be fussy, and vomit
or have seizures.
Young children with hydrocephalus also may miss developmental milestones or slip back
to earlier developmental stages. In extreme cases, a child might have "failure
to thrive" and miss growth milestones.
Signs in Older Kids
Older children won't have the easily recognizable symptom of an enlarged head because
their skull bones have fused together and can't expand to make room for the excess
fluid. In these cases, added pressure on the brain can cause severe headaches
that may wake a child in the middle of the night or early in the morning.
It's important to treat hydrocephalus right away. Untreated hydrocephalus can get
worse and cause further problems in the nervous system.
Treatment can vary depending on the age of the child, the cause of the CSF buildup
(whether from a blockage, overproduction of fluid, or another problem), and the child's
The standard treatment for hydrocephalus is a VP shunt.
In a shunt procedure, a catheter (a thin, flexible tube) is placed in the brain to
drain extra fluid down to the abdominal cavity, chambers of the heart, or a space
around the lungs. Then the fluid is absorbed by the bloodstream.
A valve (a flap that opens and closes) in the shunt system regulates the flow to
prevent over-draining and under-draining. Shunts can be used to treat hydrocephalus
from any cause.
While shunting has been an effective treatment for hydrocephalus, it is a burden
for children and their families. Some shunts last for many years, but none last forever.
When they stop working, they must be fixed with another operation. As a result, some
kids will need many operations.
Infections are a significant complication of shunt surgery. Most infections develop
within the first few months after a shunt procedure. Treatment usually means a hospital
stay for surgery to remove the infected shunt, IV antibiotics (given into a vein),
and a second operation to replace the shunt after the infection is gone.
Because of the drawbacks of shunting, other treatment can be considered in some
For older kids and adults who have hydrocephalus from a blockage, a minimally
invasive procedure with an endoscope can sometimes cure it. An endoscope is a
surgical telescope that lets a surgeon do simple operations inside the body through
very small openings.
In these cases, a neurosurgeon uses an endoscope to make a small hole in the floor
of the third ventricle, an operation called endoscopic third ventriculostomy.
This creates a pathway for fluid to drain from the brain and bypass any blockages
that are causing a backup. The body then absorbs the CSF into the bloodstream as it
Endoscopic third ventriculostomy by itself was not a very successful treatment
for infants with hydrocephalus until surgeons began to add a second step, choroid
plexus coagulation. The choroid plexus is the tissue inside the ventricles
that produces CSF, and destruction of this tissue with an electrical current makes
the endoscopic treatment much more effective.
Endoscopic third ventriculosotmy with choroid plexus coagulation can avoid a shunt
for many infants with spina bifida and for some babies with hydrocephalus from other
causes, such as prematurity.
Kids who have endoscopic treatment need to follow up with their care team often.
If they develop hydrocephalus again, doctors usually have to do a shunting procedure
because a repeat endoscopic surgery is not likely to work.
With timely treatment, many kids with hydrocephalus go on to lead normal lives.
Those with more complex medical problems, like spina bifida or bleeding in the
brain from prematurity, may have more health problems due these conditions. For these
kids, early treatment by developmental specialists, physical
therapists, and occupational
therapists can aid their recovery and greatly improve their outcomes.