Stanford Medicine Children's Health | Hydrocephalus

In this interactive 3-D animation explains hydrocephalus, a common congenital condition in which fluid builds up inside the brain. This video guides you through both the traditional surgical treatment, and an innovative repair technique that relieves the fluid pressure without implanting a permanent draining device (a shunt). You can find more information on hydrocephalus lower on this page.

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What is hydrocephalus?

Hydrocephalus is a condition in which fluid builds up inside the brain.

The brain contains a set of connected chambers, called ventricles, that are constantly producing and circulating cerebrospinal fluid (CSF). A clear, water-like fluid, CSF cushions the brain and spine, delivers nutrients to them, and carries away waste products.

CSF flows in a cycle through the brain and spine, like water in a home’s plumbing. After it has circulated, CSF is absorbed into the bloodstream to make room for newer CSF.

But as with plumbing, the brain’s fluid system can become blocked, or fail to drain correctly. That can lead to a buildup of fluid – and therefore pressure – inside the brain. The fluid buildup can expand the ventricles, and cause a child’s head to enlarge. The pressure can also lead to other potentially serious symptoms.

Hydrocephalus falls into one of two categories. “Non-communicating” hydrocephalus happens when blockages in the ventricle system prevent CSF from flowing (or “communicating”), which causes the fluid to back up and expand the ventricles. In “communicating hydrocephalus,” there are no evident blockages, but the CSF still builds up, likely because it cannot drain out of the ventricle system fast enough.

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What are the symptoms of hydrocephalus?

In addition to an increase in the circumference of the child’s head, common symptoms of hydrocephalus include vomiting, sleeplessness, seizures, and “sunset eyes”, where the child’s eyes appear to turn downwards.

The symptoms of hydrocephalus can resemble those of other conditions or medical problems, so consult your child’s doctor for a diagnosis.

How is hydrocephalus diagnosed?

When children exhibit symptoms reminiscent of hydrocephalus, doctors at Stanford Medicine Children’s Health may use a technique called fast magnetic resonance imaging (fast MRI) to further diagnose the child’s condition. Fast MRI scans take about two minutes, and do not involve sedation, or the use of radiation that accompanies some other types of imaging tools.

Hydrocephalus can also be diagnosed before birth with prenatal ultrasound, a technique that uses high-frequency sound waves and a computer to create images of blood vessels, tissues, and organs. In many cases, hydrocephalus doesn’t develop until the third trimester of pregnancy and, therefore may not be seen on ultrasounds performed earlier in pregnancy.

For slightly older children, pediatric check-ups routinely include head size measurements, where the circumference of a child’s head is compared to averages for a child or baby of that age.

Because of these diagnostic checks, hydrocephalus in the U.S. is usually caught before it becomes extreme.

How is hydrocephalus treated?

At Stanford Medicine Children’s Health, two surgical treatment options are generally considered for hydrocephalus. Be sure to consult your doctor about which is appropriate for your child.


The shunt is a reliable, standard technique that doctors have been performing since the 1950s. It involves the insertion of a tube (the shunt) into the ventricles in the brain, to redirect and drain cerebrospinal fluid down into the abdominal cavity, where it is naturally reabsorbed.

The shunt must be left in the patient's brain permanently to maintain this redirected flow.

Over time the shunt can get clogged, break, or become infected. Shunts can work well for many patients, but most will have to have their shunts replaced several times, which means repeated visits to the operating room.

Endoscopic third ventriculostomy

Stanford Medicine Children's Health offers a newer treatment that can be safer and more effective in the long term.

This advanced surgical technique, called endoscopic third ventriculostomy (ETV), does not use a shunt or any implanted hardware, and often means patients don't need to return to the hospital as many times throughout their lives.

In this procedure, surgeons use a tiny camera called an endoscope to enter the ventricles in the brain. They then make a small opening in one of the ventricles, which relieves the pressure buildup by allowing fluid to flow again. The procedure is called an ETV, or "endoscopic third ventriculostomy."

To further lower fluid pressure, surgeons will in some cases reduce the size of the choroid plexus – the tuft of vessels that produces CSF -- so it's not producing as much fluid. This is called choroid plexus coagulation (CPC).

The goal with an endoscopic third ventriculostomy is to reduce the risks associated with a shunt, and to give each child the best opportunity for a healthy and active life.

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Post-treatment considerations

Both the endoscopic procedure and the shunt have unique risks and benefits, and both require long-term monitoring of a child's ventricle size. After surgery, the medical team will work closely with the family to provide education and guidance as the child grows and develops.