What is hydrocephalus?
Hydrocephalus is a condition in which there is a lack of absorption, blockage of flow, or overproduction of the cerebral spinal fluid (CSF) that is found inside the ventricles (fluid-filled areas) of the brain. This may result in a build up of fluid that can cause the pressure inside of the head to increase and the skull bones to expand to a larger-than-normal appearance.
What are the symptoms of hydrocephalus?
Each child may experience symptoms differently. Symptoms of hydrocephalus in younger children may include the following:
In cases where hydrocephalus is not congenital, but is due to a tumor, trauma, infection, or other causes, the symptoms typically seen in older children may include the following:
- Full or bulging fontanelle (soft spot located on the top of the head)
- Increasing head circumference
- Bulging eyes and an inability of the child to look upward with the head facing forward
- Very noticeable scalp veins
- High-pitched cry
- Poor feeding
- Projectile vomiting
- Sleepiness or less alert than usual
- Developmental delays
The symptoms of hydrocephalus may resemble other conditions or medical problems. Always consult your child's physician for a diagnosis.
- Complaints of severe headaches
- Nausea and vomiting
- Changes in personality, behavior, or school performance
- Problems with bowel or bladder control
- Increased movement in the arms or legs
What causes hydrocephalus?
Hydrocephalus occurs in approximately one out of 500 births, for a variety of reasons:
Hydrocephalus can occur either as a condition present at birth (congenital), or it can be acquired later in life. When hydrocephalus is not related to a known genetic cause, it is thought that many factors, both genetic and environmental, contribute to the condition.
- Blockage of the CSF flow inside of the head
- Problems with the body absorbing the CSF
- Overproduction of the CSF
In a small percentage of children, a single gene defect on the X chromosome, or another chromosome, is responsible for the condition. In these cases, the chance for recurrence is higher.
Causes of acquired hydrocephalus may include the following:
How is hydrocephalus diagnosed?
- Bleeding inside the head
- Birth injury
- Abnormal blood vessel formation inside of the head
Hydrocephalus may be diagnosed before birth by prenatal ultrasound. In many cases, hydrocephalus does not develop until the third trimester of the pregnancy and therefore, may not be seen on ultrasounds performed earlier in pregnancy.
The diagnosis of congenital hydrocephalus may also be made at birth. During the examination, the physician obtains a complete prenatal and birth history of the child. He/she may also ask if there is a family history of any hydrocephalus or other medical problems. The physician will also ask about developmental milestones in older children since hydrocephalus can be associated with other neuromuscular disorders. Developmental delays may require further medical follow-up for underlying problems.
The child's head may appear larger than normal. A measurement of the circumference of the child's head is taken and compared to a scale that can identify normal and abnormal ranges.
Diagnostic tests that may be performed to confirm the diagnosis of hydrocephalus include:
How is hydrocephalus treated?
The Children’s neurosurgery team treats hundreds of hydrocephalus cases each year, frequently treating patients who have already been elsewhere, and who turn to us for follow-up care.
In most cases of hydrocephalus, surgery is required, and we bring to the table the sophisticated, minimally invasive approaches when appropriate. We routinely incorporate continuous intracranial pressure monitoring for maximum safety and best outcomes.
If the cause of hydrocephalus is CSF blockage, the type of surgery depends on the location and source of that blockage. If a tumor, lesion or malformation is causing the blockage, once that is addressed, CSF flow is often normalized.
If a shunt is indicated, or if a shunt needs to be replaces, the Children’s neurosurgery team regularly uses state-of-the-art shunts without anti-siphon filters to prevent CSF over-drainage
Neurosurgery for hydrocephalus usually requires a one or two day stay in our inpatient center, a wholly-new, state-of-the-art facility, designed with patients and families in mind.
While surgery for hydrocephalus is relatively routine, parents can rest assured that Children’s facilities include one of the country’s most sophisticated neuro-intensive care units, staffed by attending physicians and registered nurses trained specifically in the art and science of caring for the pediatric neurosurgery patient.
More detail about shunt placement
Surgical treatment of hydrocephalus can involve placing a mechanical shunting device into the child's head to help drain the extra CSF from the brain and redirect the extra fluid to another part of the body to be absorbed. A common type of shunt is the ventriculoperitoneal shunt.
The shunt consists of three parts:
The shunt redirects the CSF out of the head through the tubing to a location elsewhere in the body where it can be absorbed. The shunt is usually placed behind the ear and the tubing is threaded from behind the ear, under the skin to the area of the abdomen, heart, or lung. Your child's physician will determine the drainage location based on your child's condition, age, and other factors.
- a tube that is placed inside of the ventricular space
- a reservoir and valve to control the flow of CSF
- tubing that is directed under the skin to the abdomen, or less commonly to the heart or lung area
Potential complications from the shunts or surgery can include the following:
Other complications may include fever, nausea or vomiting, irritability, headache, redness and swelling along the area of the tubing, or decreased alertness or complaints of being tired. These complications require prompt medical evaluation. Following surgery, you will receive instructions on how to care for your child at home and information about signs or symptoms requiring medical care.
- Shunt malfunction that results in under-drainage or over-drainage of the CSF
Hydrocephalus can affect the brain and a child's development. The extent of the problem is dependent on the severity of the hydrocephalus and the presence of brain or other organ system problems.
The key to treating hydrocephalus is early detection, treatment, and prevention of infection. A child with hydrocephalus requires frequent medical evaluations to ensure proper shunt function. The medical team works hard with your family to provide education and guidance as your child grows and develops.
Genetic counseling may be recommended by your child's physician to discuss the risk of recurrence in future pregnancies, as well as prenatal testing for hydrocephalus.
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Hydrocephalus - Departments & Programs - Children's National Medical Center