Hydrocephalus Dr Trisha Macnair Fluid on the brain can occur at any age, but can cause specific problems for babies.

In this article

What is Hydrocephalus? Symptoms

Causes and Risk Factors Treatment and Recovery

Hydrocephalus means 'water on the brain' and is an excessive amount of fluid that surrounds the brain and spinal cord called cerebrospinal fluid (or CSF).

Symptoms depend on the cause of the hydrocephalus, the age at which it develops and the extent of damage to the brain. There may be no symptoms.

In small babies, where the bony plates of the skull haven't yet fused, the head may enlarge as the sutures (joins between bones) separate and the fontanelle (soft spot) bulge. The eyes may appear to look downwards (called the setting-sun sign). There may also be vomiting, muscle spasm and increasingly irritability.

Later there's delayed development and growth, learning disabilities, decreased movement, poor feeding, sleepiness and urinary incontinence.

In older children there may be headache, vomiting, blurred vision, loss of coordination and problems walking, confusion and drowsiness.

In hydrocephalus, CSF builds up and puts pressure on the brain, squashing the delicate tissues and causing the chambers or ventricles within the brain to swell. Without treatment damage or destruction of the brain tissues may occur.

There are two types of hydrocephalus:

• Non-communicating hydrocephalus - the flow of CSF through the brain is blocked.
• Communicating hydrocephalus - either too much CSF is produced, or it isn't reabsorbed back into the tissues as it should be, so volume increases.

There are many causes of hydrocephalus:

• Bleeding in the brain (for example if a baby is born very preterm)
• Congenital malformations (structural abnormalities that are present from birth)
• After infections in the brain
• Brain tumours
• Abnormalities in the blood vessels in the brain

The aim of treatment is to reduce and control the pressure of fluid within the skull to minimise damage to the brain.

The main treatment is surgery, usually to insert a shunt (long tube) that drains fluid from the brain,normally into the abdominal cavity, allowing the fluid to drain away Sometimes it's possible to remove the obstruction to the flow of CSF.

Untreated hydrocephalus has a high mortality rate and there may be extensive brain damage.

With treatment children may lead a fairly normal life, depending on the cause of the condition. However, there may be persistent neurological problems and there's a considerable risk of complications, such as brain infection and problems related to the shunt.

This article was last medically reviewed by Dr Orlena Kerek in February 2009