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Hydrocephalus

Medically reviewed by Drugs.com. Last updated on Jun 10, 2025.

What is hydrocephalus?

Harvard Health Publishing

Hydrocephalus, also known as "water on the brain," is a condition in which there is extra cerebrospinal fluid around the brain and spinal cord. Cerebrospinal fluid acts as a cushion for the brain and spinal cord, supplies nutrients, and takes away waste products.

Hydrocephalus can be present at birth (congenital) or can develop later (acquired).

Hydrocephalus can be classified according to its cause:

Another type of hydrocephalus, called normal pressure hydrocephalus (NPH), is an acquired type of communicating hydrocephalus in which the ventricles are enlarged but not under high pressure. NPH is most common in older adults and may be suspected because of gait abnormalities, cognitive impairment, and urinary incontinence. NPH may be the result of injury or illness, but in the majority of cases the cause is unknown.

Another type is called hydrocephalus ex-vacuo. A stroke or traumatic injury causes damage to the brain that causes brain tissue to shrink and the ventricles enlarge.

Premature infants born before 34 weeks or weighing less than 4 pounds have a higher risk of blood vessels bleeding in the brain. Severe bleeding can lead to acquired hydrocephalus, communicating or non-communicating, depending on the site and extent of the bleeding.

Symptoms of hydrocephalus

The most common symptoms of hydrocephalus vary depending on the age of onset.

In infants, symptoms include

In older children and adults, symptoms include

At any age, symptoms include

Diagnosing hydrocephalus

Congenital hydrocephalus may be diagnosed during a routine prenatal ultrasound, but often is discovered during infancy or early childhood. A doctor may suspect hydrocephalus before other symptoms appear if an infant has a head that seems to be getting larger too rapidly, or is larger than would be expected given the baby's current weight or length. If the soft spot (anterior fontanelle) is still open, an ultrasound of the head can determine if the head is getting larger due to hydrocephalus.

The doctor will ask questions about the person's medical history, and he or she will perform a physical and neurological examination. Detailed pictures of the brain may be obtained with computed tomography (CT) or magnetic resonance imaging (MRI). If these pictures reveal hydrocephalus, the child or adult usually is referred to a neurosurgeon for further evaluation and treatment.

Expected duration of hydrocephalus

Although the symptoms may subside with treatment, the duration varies according to the type and cause of the hydrocephalus.

Treatment options

The following list of medications are related to or used in the treatment of this condition.

Preventing hydrocephalus

A few of the causes of hydrocephalus can be prevented:

Treating hydrocephalus

Treatment of hydrocephalus depends on its cause and severity. Occasionally, medications are used to slow the rate of cerebrospinal fluid production temporarily. However, this has not been successful for long-term treatment.

Most cases require drainage of the excess fluid. A tube called a shunt is inserted into one of the cavities in the brain through a hole in the skull. The shunt is tunneled under the skin and carries the cerebrospinal fluid into another area of the body, such as the abdomen, where it can be absorbed.

The shunt may need to be replaced periodically as a child grows or if the shunt becomes infected or blocked.

Some people with obstructive hydrocephalus can be treated with a technique called ventriculostomy, in which a neurosurgeon makes an incision at the site of the blockage to allow cerebrospinal fluid to drain past the obstruction.

In some cases, surgeons may recommend shunt placement for congenital hydrocephalus while the fetus is still inside the mother's womb (uterus).

When to call a professional

Make an appointment to arrange prenatal care with an obstetrical provider if you become pregnant. Call your doctor if you or your child develops symptoms of hydrocephalus or has a severe head injury.

Prognosis

The outlook depends on the cause of hydrocephalus, and usually is better if the problem is diagnosed and treated early. If hydrocephalus gets worse rapidly or lasts a long time, it can cause brain damage and death.

Children with hydrocephalus are more likely to have various developmental disabilities. Even after treatment, many children with hydrocephalus have seizures, impaired intelligence, memory problems, and vision difficulties, including strabismus (abnormally aligned eyes). Children with hydrocephalus also may enter puberty earlier than normal.

With appropriate treatment, most infants with hydrocephalus survive and approximately one-third have normal cognitive function.

Additional info

National Institute of Neurological Disorders and Stroke
https://www.ninds.nih.gov/


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