Hydrocephalus - Complications of hydrocephalus

Hydrocephalus (fluid on the brain) can cause complications, or complications may develop as a result of surgery used to treat it.

Shunt malfunction

A shunt is a delicate piece of equipment prone to malfunction, usually through blockage or infection. It's estimated that up to four out of 10 shunts will malfunction in the first year after surgery. Sometimes a scan carried out after the operation shows that the shunt isn't in the best position, and that further surgery may be needed to reposition it.

If a baby or child has a shunt fitted, the shunt may become too small as your child grows, and it will need to be replaced. As most people need to have a shunt for the rest of their life, more than one replacement may be needed.

It's estimated that most children with hydrocephalus may have an average of two procedures for shunt problems before they're 10 years old.

Occasionally, when shunt tubes are positioned, bleeding can occur. This can result in nerve problems, such as weakness down one side. There's also a small risk of seizures (fits) following any surgery on the brain.

In younger children, particularly babies, cerebrospinal fluid (CSF) can run alongside the shunt rather than down it, and it can leak through the skin wound. If this occurs, further stitches will be needed to stop the leak.

Shunt blockage

A shunt blockage can be very serious because it can lead to an excess build-up of fluid on the brain, which can cause brain damage. This will cause the symptoms of hydrocephalus, such as:

• headaches
• feeling sick
• being sick
• confusion
• drowsiness or coma

In babies, you may notice their head growing larger or they may have a bulging or tense fontanelle (the soft spot on the top of their head).

Contact your care team immediately if you or your child has these symptoms. Emergency surgery will be required to replace the malfunctioning shunt.

Shunt infection

Shunt infection is also a relatively common complication. The risk of infection can be around 3-15% and is more likely to occur during the first few months after surgery.

The symptoms of a shunt infection may include:

• redness and tenderness along the line of the shunt
• a high temperature (fever) of 38ºC (100.4ºF) or above
• headache
• being sick
• neck stiffness
• tummy pain (if the shunt drains into your tummy)
• irritability or drowsiness in babies

Contact your care team immediately if you or your child has these symptoms. You may need a course of antibiotics to treat the infection and, in some cases, surgery may be required to replace the shunt.

Complications of endoscopic third ventriculostomy (ETV)

An endoscopic third ventriculostomy (ETV) is a surgical procedure where a small hole is made in the floor of your brain. Complications can occur after this type of surgery, such as:

• the hole can close
• your brain may not be able to absorb the cerebrospinal fluid that's now draining through it
• you may develop an infection, although this is less likely than after shunt surgery
• you may have bleeding inside your brain (this is usually minor)

If there's a problem with the hole, it may be possible to repeat the procedure, or you may need to have a shunt fitted (see treating hydrocephalus).

Other risks of ETV include nerve problems, such as weakness down one side of the body, double vision or hormone imbalances. Most nerve problems will get better, but there's a small risk of permanent problems. There's also a small risk of epilepsy, and a very small risk of an injury to one of the blood vessels in the brain, which may be fatal.

Long-term complications of congenital hydrocephalus

Many babies born with hydrocephalus (congenital hydrocephalus) have permanent brain damage. This can cause a number of long-term complications, such as:

• learning disabilities 
• impaired speech
• memory problems
• short attention span
• problems with organisational skills
• vision problems, such as a squint and visual impairment
• problems with physical co-ordination
• epilepsy