Water on the brain
Hydrocephalus is a buildup of fluid inside the skull that leads to brain swelling.
Hydrocephalus means "water on the brain."
Hydrocephalus is due to a problem with the flow of the fluid that surrounds the brain. This fluid is called the cerebrospinal fluid, or CSF. The fluid surrounds the brain and spinal cord and helps cushion the brain.
CSF normally moves through the brain and the spinal cord and is soaked into the bloodstream. CSF levels in the brain can rise if:
Too much CSF puts pressure on the brain. This pushes the brain up against the skull and damages brain tissue.
Hydrocephalus may begin while the baby is growing in the womb. It is common in babies who have a myelomeningocele, a birth defect in which the spinal column does not close properly.
Hydrocephalus may also be due to:
In young children, hydrocephalus may be due to:
Hydrocephalus most often occurs in children. Another type, called normal pressure hydrocephalus, may occur in adults and the elderly.
Symptoms of hydrocephalus depend on:
In infants, hydrocephalus causes the fontanelle (soft spot) to bulge and the head to be larger than expected. Early symptoms may also include:
Symptoms that may occur in older children can include:
The health care provider will examine the baby. This may show:
Repeated head circumference measurements over time may show that the head is getting bigger.
A head CT scan is one of the best tests for identifying hydrocephalus. Other tests that may be done include:
The goal of treatment is to reduce or prevent brain damage by improving the flow of CSF.
Surgery may be done to remove a blockage, if possible.
If not, a flexible tube called a shunt may be placed in the brain to reroute the flow of CSF. The shunt sends CSF to another part of the body, such as the belly area, where it can be absorbed.
Other treatments may include:
The child will need regular check-ups to make sure there are no further problems. Tests will be done regularly to check the child's development, and to look for intellectual, neurological, or physical problems.
Visiting nurses, social services, support groups, and local agencies can provide emotional support and help with the care of a child with hydrocephalus who has serious brain damage.
Without treatment, up to 6 in 10 people with hydrocephalus will die. Those who survive will have different amounts of intellectual, physical, and neurological disabilities.
The outlook depends on the cause. Hydrocephalus that is not due to an infection has the best outlook. People with hydrocephalus caused by tumors will often do very poorly.
Most children with hydrocephalus who survive for 1 year will have a fairly normal lifespan.
The shunt may become blocked. Symptoms of such a blockage include headache and vomiting. Surgeons may be able to help the shunt open without having to replace it.
There may be other problems with the shunt, such as kinking, tube separation, or infection in the area of the shunt.
Other complications may include:
Seek medical care right away if your child has any symptoms of this disorder. Go to the emergency room or call 911 if emergency symptoms occur, such as:
You should also call your provider if:
Protect the head of an infant or child from injury. Prompt treatment of infections and other disorders associated with hydrocephalus may reduce the risk of developing the disorder.
Kinsman SL, Johnston MV. Congenital anomalies of the central nervous system. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics. 20th ed. Philadelphia, PA: Elsevier; 2016:chap 591.
Rosenberg GA. Brain edema and disorders of cerebrospinal fluid circulation. In: Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL, eds. Bradley's Neurology in Clinical Practice. 7th ed. Philadelphia, PA: Elsevier Saunders; 2016:chap 88.
Last reviewed on: 11/19/2015
Reviewed by: Neil K. Kaneshiro, MD, MHA, Clinical Assistant Professor of Pediatrics, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.