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  • Just a few decades ago, children with hydrocephalus—the buildup of excess fluid in the brain—faced only one possible course of treatment: the use of a device called a shunt to drain the excess fluid. In the video above, neurosurgeon Benjamin Warf, MD—whose pioneering work has earned him a genius grantfrom the John D. and Catherine T. MacArthur Foundation-- demonstrates a one-time, minimally invasive technique—which he originally developed in Africa—which allows some children to avoid the need for shunts.

    The following pages will introduce you to the basics about hydrocephalus (which is also referred to as “water on the brain”), as well as the treatment methods for hydrocephalus —both traditional and emerging—that Children’s uses to treat babies and children.

    • The brain has four cavities, called ventricles, which naturally produce a substance called cerebrospinal fluid.
    • Cerebrospinal fluid circulates throughout the brain and spinal column, cushioning and nourishing the nervous system before being reabsorbed into the bloodstream.

    Hydrocephalus can occur if:

    • an obstruction stops the fluid from flowing naturally
    • the bloodstream cannot adequately re-absorb the fluid
    • a child's brain produces too much of this fluid

    The buildup of too much fluid in the brain creates abnormally high pressure within the skull. If this pressure isn’t relieved, the tissues in the central nervous system can be damaged, blood flow throughout the brain and skull can become dangerously restricted and neurological function can be compromised or lost.

    • Hydrocephalus is often a congenital condition, meaning babies are born with it. However, it can also develop in older children.

    Sometimes, hydrocephalus is a complication of another condition, such as:

    The long-term outlook for a child with hydrocephalus depends greatly on many factors, including how old the child is when symptoms emerge, what causes the problem and how severe the symptoms are.

    • Hydrocephalus is a progressive condition, meaning symptoms worsen over time.
    • Children with hydrocephalus eventually need a surgical intervention.
    • Many children do very well with treatment and can go on to fulfilling, active adult lives. 

    How Boston Children's Hospital approaches hydrocephalus

    Physicians at Boston Children's Hospital have been leaders in treating hydrocephalus for decades. Many decades ago, Children's became the first hospital in the world to treat children with hydrocephalus by rerouting—in a process known as shuntingexcess fluid from the brain into another body cavity. In the years since, clinicians in our Hydrocephalus Program have:

    • helped design and test the next generation of shunting devices, including the externally programmable shunt
    • introduced and refined the use of minimally invasive surgical techniques—like the endoscopic third ventriculostomy procedure (ETV), and the landmark combined endoscopic third ventriculostomy/choroid plexus cauterization procedure (ETV/CPC) pioneered by Children's neurosurgeon Benjamin Warf, MD—to more effectively treat hydrocephalus while reducing the risk of complications and the need for involved aftercare
    • taught these potentially life-saving techniques to pediatric neurosurgeons around the world

    Our approaches to treating hydrocephalus are both patient-focused and family-centered. We never lose sight of the fact that your child is, first and foremost, an individual—not merely a patient—and we include your family at every stage of the treatment process. 

    Hydrocephalus: Reviewed by Benjamin Warf, MD
    © Children’s Hospital Boston; posted in 2011

  • 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. Learn more about these treatments. 

    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. Learn more about these treatments. 

    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.

  • How is hydrocephalus diagnosed?

    When hydrocephalus is congenital (present at birth), it doesn’t usually develop until the third trimester of the mother’s pregnancy. Fetal ultrasound is used to diagnose hydrocephalus when a baby is still in the womb.

    In infants and older children, hydrocephalus is diagnosed with one or more of the following tests:

    • an ultrasound, a type of imaging that uses high-frequency sound waves to take pictures of the body's organs

    • a computed tomography (CT) scan, a non-invasive procedure using x-ray equipment and powerful computers to create detailed images of particular parts of the body

    • magnetic resonance imaging (MRI), a combination of electromagnets, radio frequency waves and computers that take two-dimensional and three-dimensional images of organs and other body structures

    • intracranial pressure monitoring, which measures the pressure in a child's skull by either: 1) placing a small, hollow tube into the brain's ventricle where the cerebrospinal fluid is produced or 2) inserting a small, hollow bolt or screw into the space just inside the brain's covering and using a monitor to take constant readings, sounding an alarm if the pressure begins to rise 

  • Boston Children's Hospital has been a worldwide innovator in diagnosing and treating hydrocephalus for decades. Our clinicians have extensive experience in treating children, adolescents and adults with all forms of the condition, and can diagnose and help parents prepare for hydrocephalus in utero.

    We use minimally invasive techniques—medical and surgical procedures that use small incisions and miniaturized cameras and tools—whenever we can. In fact, Children's has a Center for Minimally Invasive Surgery that is a global leader in creating and refining new surgical approaches.

    The excessive intracranial pressure caused by the buildup of fluid in hydrocephalus can lead to serious, long-term neurological damage, so prompt treatment is a must.  

    The treatments our Children's team uses to address hydrocephalus are:

    • shunt placement
    • endoscopic third ventriculostomy (ETV)
    • combined endoscopic third ventriculostomy/choroid plexus cauterization (ETV/CPC)

    Highly experienced in all of these procedures, neurosurgeons at Children's will work with you and your family to determine which approach best suits your child.

    Shunt placement

    In the 1950s, Children's physicians became the first pediatric hospital to treat  hydrocephalus by shunting—draining cerebrospinal fluid through a small, hollow tube that is inserted under the child's skin while he is under anesthesia. Today, shunt placement is the most common and widely used treatment for hydrocephalus.

    During the procedure, the shunt is placed either into one of the brain's ventricles, or into the fluid space in the spine. It extends to a place in the body where the excess cerebrospinal fluid can be safely absorbed—usually, either the peritoneal cavity (the space containing organs in the belly), the heart or the chest cavity.

    A one-way valve on the shunt regulates the flow of fluid. Many shunts today can also be adjusted externally, using a magnetic device that changes the pressure limit without requiring another incision and surgery. Children's neurosurgeons have helped to design and test several versions of the externally programmable shunt.

    A child who has had a shunt placement will need regular medical evaluations to ensure that the device is working properly. Like any machine, shunts may need adjustment or even replacement over time, and must be checked by a neurosurgeon on an ongoing basis.

    Your treatment team will carefully review instructions for your child's at-home shunt care and recommended long-term monitoring.

    Endoscopic third ventriculostomy (ETV)

    For some children whose hydrocephalus is caused by a blocked connection between the third and fourth ventricles of the brain, the endoscopic third ventriculostomy procedure (ETV) can be a desirable alternative to shunting. This minimally invasive procedure—which Children's neurosurgeons have helped to introduce and adapt—essentially cures hydrocephalus in children whose disease stems from an obstruction between the ventricles. It also eliminates a future dependence on shunts.

    During the ETV procedure, the neurosurgeon uses a tiny camera and a miniature surgical instrument to create an opening in the floor of the third ventricle in the brain. This allows the entrapped fluid to escape from the ventricles into its normal circulation pathway. Usually, the trapped cerebrospinal fluid begins draining immediately after the opening is made; when successful, no further intervention is needed.

    This minimally invasive surgery takes only about an hour, and children recover very quickly. Your neurosurgeon will continue to see your child regularly after undergoing ETV to make sure her intracranial pressure remains stable and that no complications develop.

    Combined endoscopic third ventriculostomy/choroid plexus cauterization (ETV/CPC)

    Benjamin Warf, MD, Children's neurosurgeon and director of Neonatal and Congenital Anomaly Neurosurgery, has pioneered a promising new treatment for hydrocephalus in infants: the combined endoscopic third ventriculostomy/choroid plexus cauterization procedure, or ETV/CPC.

    The ventricles of the brain produce cerebrospinal fluid through four rich capillary beds—one in each ventricle—called choroid plexus. Historically, neurosurgeons had treated some cases of hydrocephalus by cauterizing the choroid plexus in the first and second ventricles, thereby reducing the production of fluid.

    The technique had largely been abandoned, until Warf began combining it with endoscopic third ventriculostomy (ETV) and showed this combined procedure was superior to ETV alone in infants.

    During choroid plexus cauterization, the neurosurgeon:

    • makes a small incision in the child's scalp
    • removes a tiny window of bone in the skull
    • inserts a miniature tube called an endoscope outfitted with:
    • an eye piece at the top attached to a video camera
    • a wire passing through the endoscope that conducts precise electrical charges
    • two tiny lights
    • a lens at the end of the tube
    • advances the endoscope into the fluid spaces inside the brain (the ventricles)
    • performs the ETV by making an opening in the floor of the third ventricle
    • identifies the choroid plexus in the first and second ventricles
    • turns on the electrical charge once the tube is in position, cauterizing the choroid plexus in these two ventricles (but preserving the choroid plexus in the third and fourth ventricles, allowing continued production of cerebrospinal fluid)

    Dr. Warf combines this choroid plexus cauterization technique with the endoscopic third ventriculostomy procedure to treat some children with hydrocephalus. The dual strength of this approach reduces the production of cerebrospinal fluid in the first and second ventricles, while eliminating blockages between the third and fourth ventricles at the same time.

    Dr. Warf has published a study that reveals the combined ETV/CPC procedure is more effective in treating infants younger than 1 year than ETV alone. ETV/CPC has also proven to be a successful treatment for most infants with both hydrocephalus and spina bifida.

    Dr. Warf is training pediatric neurosurgeons in Africa and elsewhere in the ETV/CPC technique, with a goal of drastically reducing dependence on shunts in the developing world. Learn more about his work.

    Long-term outlook

    Lifelong considerations for a child with hydrocephalus

    The keys to treating hydrocephalus are:

    • early detection
    • prompt treatment
    • diligent prevention of infection during surgery

    Relieving excess intracranial pressure through shunting, ETV or ETV/CPC avoids the threat of continuing neurological damage. However, some children may continue to experience symptoms, such as headaches, which can persist even when intracranial pressure appears normal.

    Unfortunately, no procedure can reverse neurological damage that may have occurred before your child was treated. Understanding that many children with hydrocephalus are living with these long-term complications, Children's neurosurgeons and neurologists work closely with many other specialists at the hospital—including neuropsychiatrists, social workers, behavioral and learning specialists—to help our patients with lasting cognitive and developmental problems.

    Learn more about some of the caregivers you will meet during your child's treatment. 

    Helpful links

    Please note that neither Boston Children's Hospital nor the Hydrocephalus Program at Children's unreservedly endorses all of the information found at the sites listed below. These links are provided as a resource.

    Helpful links for parents and families

    Helpful links for teens

    Helpful links for younger children

  • At Boston Children’s Hospital, our care is informed by our research, and our discoveries in the laboratory strengthen the care we provide at each child's bedside. Children’s scientific research program is one of the largest and most active of any pediatric hospital in the world.

    In particular, our neurosurgery and neurology researchers are:

    • making new inroads in understanding the causes and development of nervous system diseases and disorders
    • paving ground for promising new treatments and interventions
    • offering ideas and discoveries that could lead to better treatments and cures

    Here are some of our current research projects with promise for treating hydrocephalus.

    Avoiding shunts in hydrocephalus

    During his years as a medical missionary in Africa, Boston Children’s neurosurgeon Benjamin Warf, MD, realized that many children who received shunts for hydrocephalus could not make return visits to have their shunts checked and maintained, and had nowhere to turn if their shunts failed. So he developed a one-time, minimally invasive procedure called endoscopic third ventriculostomy/choroid plexus cauterization (ETV/CPC)that can be used instead of shunting. He brought the operation back to Boston Children’s, and clinical trials are showing good results. Dr. Warf’s pioneering work earned him a 2012 genius grant” from the John D. and Catherine T. MacArthur Foundation.

    Read more in our science blog, Vector and our health blog, Thriving.

    Changing views on role of cerebrospinal fluid in hydrocephalus may lead to new treatments
    Traditionally, physicians have believed that hydrocephalus is caused by an imbalance in the production and absorption of cerebrospinal fluid—but Children's neurosurgeon Joseph Madsen, MD, and his team have discovered that the central problem in hydrocephalus might not be the amount of fluid in the brain: Instead, it may be the fluid's pulsing motion. These natural pulses, linked to the heartbeat, are believed to ensure adequate blood flow throughout the brain. However, at the same time, the smallest blood vessels need to be protected from the pulses to prevent mechanical stress.

    Madsen and his colleagues have identified the system that provides such protection in the normal brain, and are speculating that a malfunction of this system may contribute to the development of hydrocephalus.

    Making strides in developing drug therapies for hydrocephalus
    New research is suggesting several new ways to look at hydrocephalus—and even the possibility of treating the condition with drug therapies. Michael Klagsbrun, PhD, of Children's Vascular Biology Program, and Leonard Zon, MD, PhD, director of Children's Stem Cell Research Program, have created animal models of hydrocephalus—in mice and zebrafish, respectively—that could be used to test new theories and, potentially, new drug treatments.

    Creating noninvasive ways to measure intracranial pressure
    Thanks to a grant from the Boston-based nonprofit Center for Integration of Medicine and Innovative Technology (CIMIT), Children's neurosurgeon Joseph Madsen, MD, is creating a system to noninvasively measure pressure inside the skulls of patients with hydrocephalus, head injuries, subarachnoid hemorrhage and other related conditions. His goal is to create a portable device that can be used by emergency technicians, as well as by medics in battlefield situations.

    Learn more about scientific research at Children’s.

    Find out about clinical trials happening at Children's.

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