Hydrocephalus | Symptoms and Causes

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Hydrocephalus—also called “water on the brain”—is an umbrella term used to describe several different types of problems that cause cerebrospinal fluid to either build up abnormally in the brain and intracranial space, or to drain improperly.

Learning more about the processes involved in hydrocephalus can help you better understand what's next and what to expect for your child. Normally:

  • The brain’s ventricles—fluid-filled cavities—produce a clear substance called cerebrospinal fluid.
  • The cerebrospinal fluid flows over the brain, through the skull and along the spinal column, providing nutrients, flushing waste and maintaining a balanced pressure.
  • The cerebrospinal fluid is reabsorbed into the bloodstream as part of a continuous process.

Hydrocephalus occurs when any of the following happens:

  • The ventricles produce too much cerebrospinal fluid.
  • An obstruction develops, preventing the fluid from flowing normally throughout the brain and spinal column.
  • The bloodstream cannot adequately reabsorb the fluid that has been produced.

A child with hydrocephalus may have:

  • an unusually large head size
  • eyes that appear to bulge outward, or cannot look upward when the child is facing forward
  • very prominent veins in the scalp
  • developmental delays that affect reasoning, memory, speech or other learning and communication abilities
  • constant sleepiness or difficulty remaining alert
  • a poor appetite
  • frequent episodes of irritability, often for no apparent reason
  • bouts of high-pitched crying
  • severe episodes of vomiting
  • seizures

The key to treating a child with hydrocephalus is early detection, prompt treatment and diligent aftercare following either shunt placement, the endoscopic third ventriculostomy procedure (ETV) or the combined endoscopic third ventriculostomy/choroid plexus cauterization (ETV/CPC) procedure, developed by Children's neurosurgeon Benjamin Warf


What causes hydrocephalus?
Hydrocephalus is often a congenital defect—something a baby is born with—but it can also be an acquired condition, meaning it develops later in life.

Congenital hydrocephalus

While there is no known, single cause for congenital hydrocephalus, some evidence has emerged that suggests it:

  • may be linked to a single chromosomal defect
  • can be a complication of another congenital disorder, such as spina bifida or encephaloceles

Acquired hydrocephalus

Children may develop hydrocephalus as a complication of any of the following:

Signs and symptoms

What are the symptoms of hydrocephalus?
Symptoms of hydrocephalus can vary widely, depending upon:

  • the age of the child at diagnosis
  • how advanced the condition is when discovered

Symptoms in infants

Infants with hydrocephalus may have:

  • an unusually large head size
  • a rapid increase in head size
  • unusual and prolonged periods of sleepiness
  • frequent and severe episodes of vomiting
  • a downward cast to their gaze (unable to look upward while the head is facing forward)
  • unexplained seizures

Symptoms in older children

Older children with hydrocephalus often show different symptoms, since—unlike infants, whose skull plates are still malleable and in the process of fusing—their skulls cannot expand to accommodate the buildup of cerebrospinal fluid.

Rather than a bulging “soft spot” in the skull like infants with hydrocephalus tend to display, older children are more likely to have:

  • severe headaches, often accompanied by nausea and vomiting
  • swelling of the optic disk within the eye's optic nerve
  • blurred or double vision
  • problems with balance
  • difficulty looking upward when the head is facing forward
  • poor physical coordination
  • difficulty standing or walking
  • urinary incontinence
  • chronic lethargy or sleepiness
  • bouts of irritability for no apparent reason
  • slowed or halted developmental progress in speech, reasoning and other milestones
  • difficulty remembering and focusing
  • sudden changes in personality

You should seek treatment from a qualified medical professional right away if you notice these warning signs in your child. 


Q: Will my child be OK?
A: The severity and symptoms of hydrocephalus can vary widely in from child to child. A child whose hydrocephalus is already very advanced when diagnosed—or a child who has another complication in addition to hydrocephalus—may have more serious physical and cognitive problems. These children may require more in-depth treatments over the long term than other children with the disease.

Many children with hydrocephalus do very well when their increased intracranial pressure is corrected by shunt placement or by either the endoscopic third ventriculostomy procedure (ETV) or the combined endoscopic third ventriculostomy/choroid plexus cauterization procedure (ETV/CPC), which was developed by Children's Neonatal and Congenital Anomaly Neurosurgery Director Benjamin Warf, MD

When these treatments are combined with occupational therapy and physical therapy,  children with hydrocephalus usually go on to live healthy, productive adult lives.

Your treating clinician can give you a better sense of what your child will need over the long term, depending on his individual symptoms and circumstances.

Q: Is hydrocephalus common?
It is believed that as many as one in 500 children has hydrocephalus. Experts are working to develop a registry that will help them better track how many children around the world have this condition.

Q: Does my child have to cut back on physical activities?
A: Whether your child needs to cut back significantly on activities—or cut back at all—depends greatly on her age and how pronounced her symptoms are.

Since head trauma can exacerbate and complicate hydrocephalus, a child with the condition should always wear a protective helmet for activities like bike riding. You should talk to your treating clinician about other recommended exercise restrictions or practices for your child.

Q: Is my child going to need surgery?
A: Since hydrocephalus is a progressive condition—meaning symptoms grow more severe over time—most children eventually need either a shunt placement, endoscopic third ventriculostomy procedure (ETV) or combined endoscopic third ventriculostomy/choroid plexus cauterization procedure (ETV/CPC) to restore equilibrium to their intracranial pressure.  

Children's neurosurgeons have extensive experience performing each of these procedures in children of all ages.

Q: What do I need to look out for if my child has been diagnosed with hydrocephalus?
Parents of children with hydrocephalus should always be watchful for changes in their child’s:

  • head shape and size
  • movement
  • activity levels
  • temperament
  • appetite
  • cognitive functioning (memory, learning, speech and language)

You should seek medical help promptly if your child has:

  • headaches
  • poor appetite
  • difficulty or changes in standing, walking and moving
  • nausea
  • vomiting
  • protruding veins in the scalp
  • sudden periods of irritability with no apparent cause
  • sudden personality changes
  • problems in mental functioning (memory, reasoning)
  • problems in speaking/communicating
  • incontinence
  • double vision
  • blurred vision
  • constant downward gaze/difficulty lifting the eyes to look upward when the head is facing forward
  • periods of inconsolable, high-pitched crying
  • seizures

Q: Can doctors diagnose hydrocephalus while a baby is still in the womb?
A: Children’s Advanced Fetal Care Center can diagnose babies with congenital problems like hydrocephalus in utero.  

Q: Is there a cure for hydrocephalus?
A: Hydrocephalus is a progressive condition, meaning that symptoms will worsen over time. If a child’s hydrocephalus is not addressed:

  • his intracranial pressure will increase
  • blood flow in his brain can become dangerously restricted
  • tissues in his nervous system can sustain serious damage

As a result, for most children with hydrocephalus, more involved treatments—usually the placement of a shunt, an endoscopic third ventriculostomy procedure (ETV) or a combined endoscopic third ventriculostomy/choroid plexus cauterization procedure (ETV/CPC)— eventually become necessary.

The good news is that all of these techniques have an excellent success rate for allowing proper draining of the cerebrospinal fluid, restoring normal intracranial pressure and blood flow and preventing further neurological damage.

We are grateful to have been ranked #1 on U.S. News & World Report's list of the best children's hospitals in the nation for the third year in a row, an honor we could not have achieved without the patients and families who inspire us to do our very best for them. Thanks to you, Boston Children's is a place where we can write the greatest children's stories ever told.”
- Sandra L. Fenwick, President and CEO

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