Hydrocephalus is the buildup of fluid in the cavities (ventricles) deep within the brain. The excess fluid increases the size of the ventricles and puts pressure on the brain.
Cerebrospinal fluid normally flows through the ventricles and bathes the brain and spinal column. But the pressure of too much cerebrospinal fluid associated with hydrocephalus can damage brain tissues and cause a range of brain function problems.
Hydrocephalus can happen at any age, but it occurs more frequently among infants and adults 60 and over. Surgical treatment for hydrocephalus can restore and maintain normal cerebrospinal fluid levels in the brain. Different therapies are often required to manage symptoms or problems resulting from hydrocephalus.
The signs and symptoms of hydrocephalus vary somewhat by age of onset.
Common signs and symptoms of hydrocephalus in infants include:
Changes in the head
- An unusually large head
- A rapid increase in the size of the head
- A bulging or tense soft spot (fontanel) on the top of the head
Physical signs and symptoms
- Nausea and vomiting
- Sleepiness or sluggishness (lethargy)
- Poor eating
- Eyes fixed downward (sunsetting of the eyes)
- Problems with muscle tone and strength
Toddlers and older children
Among toddlers and older children, signs and symptoms might include:
Physical signs and symptoms
- Blurred or double vision
- Abnormal eye movements
- Abnormal enlargement of a toddler's head
- Sleepiness or sluggishness
- Nausea or vomiting
- Unstable balance
- Poor coordination
- Poor appetite
- Loss of bladder control or frequent urination
Behavioral and cognitive changes
- Change in personality
- Decline in school performance
- Delays or problems with previously acquired skills, such as walking or talking
Young and middle-aged adults
Common signs and symptoms in this age group include:
- Loss of coordination or balance
- Loss of bladder control or a frequent urge to urinate
- Vision problems
- Decline in memory, concentration and other thinking skills that may affect job performance
Among adults 60 years of age and older, the more common signs and symptoms of hydrocephalus are:
- Loss of bladder control or a frequent urge to urinate
- Memory loss
- Progressive loss of other thinking or reasoning skills
- Difficulty walking, often described as a shuffling gait or the feeling of the feet being stuck
- Poor coordination or balance
When to see a doctor
Seek emergency medical care for infants and toddlers with these signs and symptoms:
- A high-pitched cry
- Problems with sucking or feeding
- Unexplained, recurrent vomiting
Seek prompt medical attention for other signs or symptoms in any age group.
More than one condition can cause the problems associated with hydrocephalus, so it's important to get a timely diagnosis and appropriate care.
Hydrocephalus is caused by an imbalance between how much cerebrospinal fluid is produced and how much is absorbed into the bloodstream.
Cerebrospinal fluid is produced by tissues lining the ventricles of the brain. It flows through the ventricles by way of interconnecting channels. The fluid eventually flows into spaces around the brain and spinal column. It's absorbed primarily by blood vessels in tissues on the surface of the brain.
Cerebrospinal fluid plays an important role in brain function by:
- Keeping the brain buoyant, allowing the relatively heavy brain to float within the skull
- Cushioning the brain to prevent injury
- Removing waste products of the brain's metabolism
- Flowing back and forth between the brain cavity and spinal column to maintain a constant pressure within the brain — compensating for changes in blood pressure in the brain
Too much cerebrospinal fluid in the ventricles occurs for one of the following reasons:
- Obstruction. The most common problem is a partial blockage of the flow of cerebrospinal fluid, either from one ventricle to another or from the ventricles to other spaces around the brain.
- Poor absorption. Less common is a problem with absorbing cerebrospinal fluid. This is often related to inflammation of brain tissues from disease or injury.
- Overproduction. Rarely, cerebrospinal fluid is created more quickly than it can be absorbed.
In many cases, the cause of hydrocephalus is unknown. However, a number of developmental or medical problems can contribute to or trigger hydrocephalus.
Hydrocephalus present at birth (congenital) or shortly after birth can occur because of any of the following:
- Abnormal development of the central nervous system that can obstruct the flow of cerebrospinal fluid
- Bleeding within the ventricles, a possible complication of premature birth
- Infection in the uterus — such as rubella or syphilis — during pregnancy, which can cause inflammation in fetal brain tissues
Other contributing factors
Other factors that can contribute to hydrocephalus among any age group include:
- Lesions or tumors of the brain or spinal cord
- Central nervous system infections, such as bacterial meningitis or mumps
- Bleeding in the brain from a stroke or head injury
- Other traumatic injury to the brain
In most cases, hydrocephalus progresses, which means complications, including intellectual, developmental and physical disabilities, can occur if it's not treated. It can also be life-threatening. Less severe cases, when treated appropriately, might have few, if any, serious complications.
A diagnosis of hydrocephalus is usually based on:
- Your answers to the doctor's questions about signs and symptoms
- A general physical exam
- A neurological exam
- Brain-imaging tests
The type of neurological exam will depend on a person's age. The neurologist might ask questions and conduct relatively simple tests in the office to judge muscle condition, movement, well-being and how well the senses are functioning.
Imaging tests that can help diagnose hydrocephalus and identify underlying causes of the symptoms include:
- Ultrasound. This test is often used for an initial assessment for infants because it's a relatively simple, low-risk procedure. The ultrasound device is placed over the soft spot (fontanel) on the top of a baby's head. Ultrasound might also detect hydrocephalus before birth during routine prenatal examinations.
MRI. This test uses radio waves and a magnetic field to produce detailed images of the brain. This test is painless, but it is noisy and requires lying still.
MRI scans can show enlarged ventricles caused by excess cerebrospinal fluid. They can also be used to identify causes of hydrocephalus or other conditions contributing to the symptoms.
Children might need mild sedation for some MRI scans. However, some hospitals use a fast version of MRI that generally doesn't require sedation.
CT scan. This specialized X-ray technology produces cross-sectional views of the brain. Scanning is painless and quick. But this test also requires lying still, so a child usually receives a mild sedative.
CT scanning produces less detailed images than MRI does and causes exposure to a small amount of radiation. CT scans for hydrocephalus are usually used only for emergency exams.
One of two surgical treatments can be used to treat hydrocephalus.
The most common treatment for hydrocephalus is the surgical insertion of a drainage system, called a shunt. It consists of a long, flexible tube with a valve that keeps fluid from the brain flowing in the right direction and at the proper rate.
One end of the tubing is usually placed in one of the brain's ventricles. The tubing is then tunneled under the skin to another part of the body — such as the abdomen or a heart chamber — where the excess fluid can be more easily absorbed.
People who have hydrocephalus usually need a shunt system for the rest of their lives. They require regular monitoring.
Endoscopic third ventriculostomy
Endoscopic third ventriculostomy is a surgical procedure that can be used for some people. The surgeon uses a small video camera see inside the brain. Your surgeon makes a hole in the bottom of one of the ventricles or between the ventricles to enable cerebrospinal fluid to flow out of the brain.
Complications of surgery
Both surgical procedures can result in complications. Shunt systems can stop draining cerebrospinal fluid or poorly regulate drainage because of mechanical problems, blockage or infections. Complications of ventriculostomy include bleeding and infections.
Any failure requires prompt attention, surgical revisions or other interventions. Fever or recurrence of the original symptoms of hydrocephalus should prompt an appointment with your doctor.
Some people with hydrocephalus, particularly children, might need additional treatment, depending on the severity of long-term complications of hydrocephalus.
Children's care teams might include the following:
- Pediatrician or physiatrist, who oversees the treatment plan and medical care
- Pediatric neurologist, who specializes in the diagnosis and treatment of neurological disorders in children
- Occupational therapist, who specializes in therapy to develop everyday skills
- Developmental therapist, who specializes in therapy to help your child develop age-appropriate behaviors, social skills and interpersonal skills
- Mental health professional, such as a psychologist or psychiatrist
- Social worker, who assists the family with getting needed services and planning for transitions in care
Children who are in school will likely need special education teachers, who address learning disabilities, determine educational needs and identify needed resources.
Adults with more-severe complications also might need the services of occupational therapists, social workers, specialists in dementia care or other medical specialists.
Coping and support
With the help of rehabilitative therapies and educational interventions, many people with hydrocephalus live with few limitations.
There are many resources available to provide emotional and medical support as you parent a child with hydrocephalus. Children with developmental problems due to hydrocephalus might be eligible for government-sponsored health care and other support services. Check with your state or county social services agency.
Hospitals and organizations serving people with disabilities are good resources for emotional and practical support, as are doctors and nurses. Ask for help connecting with other families who are coping with hydrocephalus.
Adults living with hydrocephalus might find valuable information and support from organizations dedicated to hydrocephalus education and support, such as the Hydrocephalus Association.
Should you be vaccinated against meningitis?
Ask your doctor if you or your child should receive a vaccine against meningitis, once a common cause of hydrocephalus. The Centers for Disease Control and Prevention recommends meningitis vaccination for preteen children and boosters for teenagers. Vaccination is also recommended for younger children and adults who might be at increased risk of meningitis for any of the following reasons:
- Traveling to countries where meningitis is common
- Having an immune system disorder called terminal complement deficiency
- Having a damaged spleen or having had the spleen removed
- Living in a college dormitory
- Joining the military
Preparing for an appointment
The timing of diagnosing a child with hydrocephalus can depend on how severe the symptoms are, when problems appear, and whether there were major risk factors for hydrocephalus during the pregnancy or delivery. In some cases, hydrocephalus can be diagnosed at birth or before birth.
It's important to take your child to all regularly scheduled well-baby visits. Your child's doctor will monitor your child's development in key areas, including:
- Head size, rate of head growth and overall body growth
- Muscle strength and tone
- Age-appropriate motor skills
- Sensory abilities — vision, hearing and touch
Questions you should be prepared to answer during regular checkups might include the following:
- What concerns do you have about your child's growth or development?
- How well does he or she eat?
- How does your child respond to touch?
- Is your child reaching certain milestones in development, such as rolling over, pushing up, sitting up, crawling, walking or speaking?
Preparing for other doctor visits
If you're seeing a doctor because of the recent onset of symptoms, you'll likely start by seeing your primary care doctor or your child's pediatrician. After an initial evaluation, your doctor might refer you to a doctor who specializes in the diagnosis and treatment of conditions that affect the brain and nervous system (neurologist).
Be prepared to answer the following questions about your symptoms or on your child's behalf:
- What signs or symptoms have you noticed? When did they begin?
- Have these signs or symptoms changed over time?
- Do these signs or symptoms include nausea or vomiting?
- Have you or your child had any vision problems?
- Have you or your child had a headache or fever?
- Have you noticed personality changes, including increased irritability?
- Has your child's school performance changed?
- Have you noticed new problems with movement or coordination?
- Is your child abnormally sleepy or lacking energy?
- Has your infant had seizures?
- Has your infant had problems with eating or breathing?
- In older children and adults, have signs and symptoms included loss of bladder control and frequent urination?
- Have you or your child had a recent head injury?
- Have you or your child recently begun a new medication?