hydrocephalus; hydro; cephalus; spina; bifida; shunt; blockage; Arnold;
chiari; ventricles; meningitis; head; injury; valve; CFS; cerebral; spinal;
fluid; learn; learning; behaviour;
Hydrocephalus (hydro means water, cephalus means head) occurs when there is a blockage in the circulation of cerebrospinal fluid (CSF) from spaces within the brain (ventricles) out over the surface of the brain and down the spinal cord (the column of nerve cells which carries messages between the brain and the body).
When too much CSF gets trapped in the pathway, the ventricles expand and put pressure on the brain.
Hydrocephalus can be
- Congenital - present before birth (the usual situation)
- About 80% of children with spina bifida will have hydrocephalus.
- Some children will be born with hydrocephalus without spina bifida.
- Acquired - develops after birth, including as a result of an injury, infection around the brain (meningitis), bleeding in or around the brain due to prematurity, or a brain tumour.
Continued raised pressure on the brain due to hydrocephalus will cause damage to the brain.
Each child living with hydrocephalus will be different, and each child needs to be assessed and worked with on an individual basis.
Hydrocephalus is usually a lifelong condition that is controlled, not cured. Treatment generally leads to the person having a full and active life.
CSF is a clear, colourless fluid that looks like water and is made up of water, salt, glucose and cells.
- It provides nutrients to the brain and spinal cord and takes away waste products.
- It also provides protection to the brain and spinal cord by acting as a shock absorber between the skull and the brain, and between the spinal cord and the bones around it (the spine).
CSF is produced in the lining of spaces (the ventricles) within the brain at a rate of around 20-25mls each hour, and after moving around the brain it passes back into blood stream.
- Non-communicating hydrocephalus (the usual situation) is when there is a blockage in the flow of CSF.
- In spina bifida the lower part of the brain goes further down the spinal cord than usual. This is called the Arnold Chiari Malformation. Some children with spina bifida develop hydrocephalus before birth, while others develop it when the back is closed surgically.
- Other causes of non-communicating hydrocephalus include tumours or meningitis.
- Communicating hydrocephalus occurs when more CSF is produced than can be reabsorbed. It can also be as a result of meningitis or a traumatic brain injury.
Most people with hydrocephalus have a partial blockage. The size and the speed of enlargement of the ventricles vary.
is hydrocephalus detected?
Hydrocephalus can be detected by observing a child's behaviour, by a physical examination and by some tests.
In a baby:
- High pitched cry
- Poor feeding
- Being sleepier than usual
- Large head
- Fontanelles (soft spots on the top of the head) being full and hard.
In a child:
- Nausea and vomiting
- Lethargy (sleeping more than usual, being difficult to wake up, not wanting to play as usual)
Signs (what is found on examination) include
- Large head size or rapidly growing head where the circumference when plotted is crossing normal growth rates.
- The presence of full fontanelles ('soft spot') in a baby
- 'Sunset eyes' – where the white of the eye can be seen at the top of the eye and the cornea (coloured part of the eye) is low and partly covered by the lower eyelid.
- "Frontal Bossing" - the forehead more prominent.
- An ultrasound examination may be done in a baby, checking the size of the ventricles.
- Computerised tomography (CT scan) or MRI will show sizes of the ventricles.
- CSF flow study, looking at the movement of CSF through the ventricles, over the brain and down the spinal cord, which will show where the blockage is.
Some people can have enlarged ventricles with no signs or problems. In others the effects of hydrocephalus depend in part on the cause of the hydrocephalus.
- Children with spina bifida will have physical problems due to effects on the spinal cord.
- If they also have hydrocephalus they often have some learning problems and difficulty concentrating.
- Most are within the normal range of intelligence.
- Some can have vision problems, epilepsy, headaches and early onset of puberty.
- Many young people with spina bifida and hydrocephalus have completed university studies.
Other causes of hydrocephalus such as meningitis or a brain tumour may have other effects on brain function.
The aim of treatment is to lower the pressure inside the brain. Different types of operations will be done for different types of hydrocephalus.
- When there is a non-communicating hydrocephalus such as 'Aqueductal stenosis' an operation is done to insert a shunt to drain the CSF.
- A procedure called an 'Endoscopic third ventriculostomy' may be done in children over one year of age. It is another way of treating hydrocephalus. A hole is made in the floor of the third ventricle, one of the fluid filled chambers within the brain, to allow free circulation of the CSF.
A shunt consists of
- Catheter: hollow flexible tube inserted into a ventricle in the brain or into the space around the spinal cord, depending on the type of hydrocephalus that the child has.
- A valve which controls the amount, pressure and direction of CSF flow (so that CSF can only flow away from the brain).
- Another tube leading from the valve under the lining of the abdominal cavity called the peritoneum where the CSF can be absorbed.
These types of shunt are called Ventriculo-peritoneal (VP) shunt (from the brain) or Lumbar-peritoneal (LP) shunt (from the spinal cord).
The whole of the shunt will be under the surface of the body.
- With a VP shunt there will be a cut above and behind one ear, where the catheter has been placed into the ventricle and where the valve is placed, and with a VL shunt there will be a cut on the back.
- There will also be a cut on the abdomen which is needed to put the lower end of the tubing into the correct place within the abdomen.
Most children with spina bifida who have hydrocephalus will have a shunt inserted within days or weeks after birth.
with the shunt
The shunt may stop working correctly.
- Sometimes the catheter and tubing can become twisted, or separated at the connections
- The catheter and tubing can be blocked by blood or other tissue
- As the child grows and becomes taller the tubing leading to the abdomen will eventually become too short.
- An infection could develop around the shunt.
About 40% of shunts will need to be changed (revised) within the 1st year after insertion, and about 80% will need a revision within 10 years. Some will need several revisions.
that indicate shunt malfunction
These can vary from person to person.
Initially there may be some minor changes in personality, learning ability and coordination. Parents often say they have a 'gut' feeling that something is not right.
If a person has any of the symptoms listed below a doctor must be contacted urgently
- Vomiting or loss of appetite
- Complaining of headaches while sitting up that stop while lying down (postural headaches)
- Blurred vision
- Poor concentration and memory
- Changes in coordination of arms and legs
- Seizures (fits)
- Losing control of urine or faeces (poo)
- Also, in an infant, bulging fontanelle and increasing head size.
The doctor may then order an ultrasound, or CT scan, or MRI. This may show an increase in the size of the ventricles indicating that the shunt is blocked. Depending on what the scan shows more tests may be ordered to help with decisions about unblocking or changing the shunt.
About 5 -10% of people will develop an infection after each shunt operation.
- Infections occur more often in babies than older children or adults.
- Skin infections are the most common, but sometimes the shunt itself can be infected and can block.
- The child can develop the symptoms listed above, and also may have a fever, stiff neck, redness, pain and tenderness around the shunt, and abdominal pain.
The doctor will usually diagnosis a shunt infection by 'tapping' (removing a small amount of CSF with a needle) the valve chamber. Shunt infections need to be treated with antibiotics, and removal and replacement of the shunt.
Occasionally the shunt will drain too much fluid. If this happens the child will complain of headaches while sitting up which will get better when they are lying down. If this happens it is important that your doctor is contacted.
of seizures (fits)
If your child has a seizure (twitching of arms and or legs) and this is the first time this has happened, then follow the instructions below.
First aid for a seizure:
- roll them on their side
- protect them from injury by removing any objects
- do not restrain them or put any thing in their mouth
- monitor the airway
- get someone to call an ambulance.
If your child has had seizures before your doctor may have given you a management plan about what to do before you get medical help.
with a shunt
Parents and older children need to be taught the signs and symptoms of shunt failure. They also need to have a management plan about who to contact and when to go to hospital. It can be useful for them to carry a protocol for managing a shunt failure in case the doctor they see is not familiar with signs of a shunt failure or with how to manage a shunt failure.
Fact sheets are available on the Women's and Children's Hospital site http://www.wch.sa.gov.au/services/az/divisions/psurg/neuro/index.html
Things to watch for
- Avoid contact sports that may cause injury to the shunt valve or head injury. Football, lacrosse or other contact sports are not recommended. Encourage low impact sports such as tennis or swimming. A helmet should be worn for skiing or other sports that may cause head injury.
- If a child suffers head injury they require close observation for signs of neurological changes and must be taken to a hospital if these develop. (For example they may develop a headache, start vomiting or become more drowsy or irritable than usual.)
- Discourage the child from wearing handbags, shoulder bags, or backpacks on the side where the shunt tubing passes down the side of the neck, as pressure on the tubing may cause a break or kink in the tubing resulting in shunt malfunction.
- Constipation can put pressure on the end of the shunt, stopping it draining completely and it might be a factor in the development of a shunt malfunction. Children might need to have a high fibre diet and use laxatives to maintain regular bowel movements.
The information on this site should not be used as an alternative to professional care. If you have a particular problem, see a doctor, or ring the Parent Helpline on 1300 364 100 (local call cost from anywhere in South Australia).
This topic may use 'he' and 'she' in turn - please change to suit your child's sex.