Related concepts:

Communicating hydrocephalus, Noncommunicating hydrocephalus, Obstructive hydrocephalus, Water on the brain

Introduction to hydrocephalus:

The brain and spinal cord are bathed and protected by cerebrospinal fluid (CSF). A baby has less than 2 ounces of spinal fluid; a typical adult has about 5 ounces.

A typical child makes about 2 ounces of new spinal fluid every 3 hours. This spinal fluid flows in and around the brain through waterways and aqueducts before it completes its journey and is reabsorbed.

What is hydrocephalus?

Hydrocephalus is the build-up of excessive spinal fluid. This can be caused by a blockade or narrowing along the CSF circulation route (called obstructive or noncommunicating hydrocephalus). It can also be caused by impaired resorption of spinal fluid that has completed its journey (communicating hydrocephalus). Very rarely, hydrocephalus can be caused by over-production of CSF.

Who gets hydrocephalus?

Sometimes abnormally narrow CSF passageways run in families. Sometimes hydrocephalus is the result of other problems, such as neural tube defects (e.g. spina bifida), meningitis, encephalitis, head bleeds, brain tumors, mumps, tuberculosis, or streptococcal infections.

What are the symptoms of hydrocephalus?

In small children, the main sign of hydrocephalus is a rapidly expanding head. The anterior fontanel is wide open.

In older children, hydrocephalus is not as easy to detect.

Either way, vomiting, decreased appetite, and irritability are common. Between bouts of irritability, kids are often somewhat lethargic.

The eyes may deviate downward (the sunset sign). General muscle tone may be increased, and reflexes may be too brisk.

Older children often describe a headache.

Is hydrocephalus contagious?

No, although some of the underlying causes are contagious.

How long does hydrocephalus last?

Hydrocephalus often continues until it is treated.

How is hydrocephalus diagnosed?

The diagnosis is suspected based on the history and the physical exam. It is confirmed with imaging studies of the head, such as CT, MRI, or ultrasound.

How is hydrocephalus treated?

While medicines are available to temporarily decrease CSF production, the mainstay of treatment is usually to place a shunt to remove the excess CSF.

How can hydrocephalus be prevented?

Often hydrocephalus cannot be prevented.