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 large spectrum of impairments in brain function.
Although hydrocephalus can occur at any age, it's more common among infants and older adults.
Surgical treatment for hydrocephalus can restore and maintain normal cerebrospinal fluid levels in the brain. A variety of interventions are often required to manage symptoms or functional impairments resulting from hydrocephalus.
The signs and symptoms of hydrocephalus vary generally 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
- Poor feeding
- Eyes fixed downward (sunsetting of the eyes)
- Deficits in muscle tone and strength, responsiveness to touch, and expected growth
Toddlers and older children
Among toddlers and older children, signs and symptoms may include:
- Blurred or double vision
- Abnormal enlargement of a toddler's head
- Difficulty remaining awake or waking up
- Nausea or vomiting
- Unstable balance
- Poor coordination
- Poor appetite
Behavioral and cognitive changes
- Change in personality
- Problems with attention
- 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:
- Difficulty in remaining awake or waking up
- Loss of coordination or balance
- Loss of bladder control or a frequent urge to urinate
- Impaired vision
- 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
- Slower than normal movements in general
When to see a doctor
Seek emergency medical care for infants and toddlers experiencing these signs and symptoms:
- A high-pitched cry
- Problems with sucking or feeding
- Unexplained, recurrent vomiting
- An unwillingness to bend or move the neck or head
- Breathing difficulties
Seek prompt medical attention for other signs or symptoms in any age group.
Because more than one condition can result in the problems associated with hydrocephalus, 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 and eventually flows into spaces around the brain and spinal column. It's absorbed primarily by blood vessels in tissues near the base 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
Excess cerebrospinal fluid in the ventricles occurs for one of the following reasons:
- Obstruction. The most common problem is a partial obstruction of the normal 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 the mechanisms that enable the blood vessels to absorb cerebral spinal fluid. This is often related to inflammation of brain tissues from disease or injury.
- Overproduction. Rarely, the mechanisms for producing cerebrospinal fluid create more than normal and more quickly than it can be absorbed.
In many cases, the exact event leading to 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 may occur because of any of the following:
- Abnormal development of the central nervous system that can obstruct the flow of cerebral spinal fluid
- Bleeding within the ventricles, a possible complication of premature birth
- Infection in the uterus during a pregnancy, such as rubella or syphilis, that 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 stroke or head injury
- Other traumatic injury to the brain
Long-term complications of hydrocephalus can vary widely and are often difficult to predict.
If hydrocephalus has progressed by the time of birth, it may result in significant intellectual, developmental and physical disabilities. Less severe cases, when treated appropriately, may have few, if any, notable complications.
Adults who have experienced a significant decline in memory or other thinking skills generally have poorer recoveries and persistent symptoms after treatment of hydrocephalus.
The severity of complications depends on:
- Underlying medical or developmental problems
- Severity of initial symptoms
- Timeliness of diagnosis and treatment
Hydrocephalus is not a preventable condition. However, there are ways to reduce the risk of hydrocephalus:
- If you're pregnant, get regular prenatal care. Following your doctor's recommended schedule for checkups during pregnancy can reduce your risk of premature labor, which places your baby at risk of hydrocephalus and other complications.
- Protect against infectious illness. Follow the recommended vaccination and screening schedules for your age and sex. Preventing and promptly treating the infections and other illnesses associated with hydrocephalus may reduce your risk.
To prevent head injury:
- Use appropriate safety equipment. For babies and children, use a properly installed, age- and size-appropriate child safety seat on all car trips. Make sure all your baby equipment — crib, stroller, swing, highchair — meets all safety standards and is properly adjusted for your baby's size and development. Children and adults should wear helmets while riding bicycles, skateboards, motorcycles, snowmobiles or all-terrain vehicles.
- Always wear a seat belt in a motor vehicle. Small children should be secured in child safety seats or booster seats. Depending on their size, older children may be adequately restrained with seat belts.
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. It's also recommended for younger children and adults who may 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
Aug. 02, 2014