
Hydrocephalus — from "hydro," the Greek word for water, and "cephalus," the Greek word for head — occurs when abnormal amounts of cerebrospinal fluid accumulate in the brain's cavities, called subarachnoid space.
Acquired hydrocephalus occurs after birth when a tumor, injury or disease blocks the absorption of cerebrospinal fluid in the brain. Babies may also be born with hydrocephalus, called congenital hydrocephalus. Affecting one out of every 1,000 newborns, congenital hydrocephalus is caused by a brain malformation or birth defect.
Cerebrospinal fluid, or CSF, is a clear, colorless liquid that normally surrounds the brain and spinal cord, protecting them from injury, bringing them nutrients and taking away waste. In a healthy person, all CSF produced by the brain is absorbed by the body. In hydrocephalus, the fluid fails to drain and accumulates, creating pressure on the brain.
A build-up of CSF may result from one of three reasons:
Acquired hydrocephalus is caused by injuries or conditions that develop after birth, such as a hemorrhage, meningitis, head trauma, tumors and cysts.
Symptoms in older children may include:
During your visit to UCSF Benioff Children's Hospital, our doctors and other staff members will thoroughly evaluate your child. We will ask you about your child's medical history as well as the medical history of your immediate family.
If your pediatrician has sent us your child's medical records, we will review this information as well. Be sure to tell your child's doctors about medications your child is currently using, including over-the-counter medications, vitamins, nutritional supplements and herbal remedies.
Hydrocephalus is assessed by measuring its effect on the brain. If cerebrospinal fluid builds up, it frequently leads to enlarged cavities visible on diagnostic scans of the head.
Your child's evaluation will include imaging tests such as:
Acquired hydrocephalus is most commonly treated by either removing the cause of the condition, such as a tumor or other blockage, or inserting a shunt. The shunt is a flexible plastic tube that diverts excess cerebrospinal fluid from the brain to the abdomen where it can be absorbed back into the body. A valve within the shunt regulates and prevents excessive drainage.
A limited number of patients can be treated with an alternative procedure called endoscopic third ventriculostomy, or ETV. In this procedure, a small hole is made in the floor of the third ventricle of the brain, one of the brain's four cavities. This allows the cerebrospinal fluid to bypass the obstruction and flow toward an area where it can be reabsorbed by the body.
If you have questions about your child's treatment, feel free to ask your child's doctors, nurses and therapists. If the treatment includes medication, be sure that your child takes it exactly as instructed. Remember to bring your child to all follow-up appointments.
Reviewed by health care specialists at UCSF Benioff Children's Hospital.
Last updated
September 27, 2011

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