Guidelines for General Practitioners

these two factors that has led to our Medical Advisory Committee producing this leaflet. Only General Practitioners who are responsible for the care of someone with hydrocephalus will receive this information, and it is sent only with the permission of the patient, or his or her parents.

Problems encountered in a general practice may include subtle symptoms of a shunt malfunction.

Other symptoms can be more obvious indications of a possible malfunction They may include: Vomiting, headache, dizziness, photophobia and other visual disturbances, drowsiness and fits.

Or there may be symptoms of a possible chronic shunt malfunction. These include:

Fatigue, general malaise, visuo-perceptual problems, behavioural changes, decline in academic performance, being ‘not right’ from the carer’s point of view.

HydrocephalusGuidelines for General Practitioners

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Name of Patient:

Date of Birth: / /

Address:

Name of neurosurgeon:

Neurosurgeon unit attended:

Unit telephone no.

Shine has been listening to people with hydrocephalus, their parents and families for over 40 years and we are frequently approached by medical practitioners for information about the management of this condition. It is the combination of

raised intracranial pressure, with compression of the brain tissue. In babies the head will enlarge but in adults and older children, when the cranial sutures have fused, the head size cannot increase.

How is Hydrocephalus managed?

Hydrocephalus cannot be cured, but inserting a shunt system to drain away the excess CSF can control it. The shunt consists of a short catheter inserted into the lateral ventricles in the brain and connected to a one-way valve. The distal catheter leads downwards from the valve either into the atrium (ventriculo-atrial

Many people find it difficult or painful to absorb medical information at the emotionally traumatic time of their, or their child‘s, diagnosis of hydrocephalus and looking to the future can seem frightening when a shunt is inserted. For these reasons, many patients choose to discuss their situation with their more familiar general practitioner once they or their child are discharged from hospital.

Research findings show that parents never forget how news is broken and explanations are given, and that a successful relationship between a family and general practitioner can develop the confidence to face the future and the security to live comfortably in the present.

A good understanding of their own or their child’s condition enables a family or individual to live life with the minimum of distress caused by uncertainty.

When people contact Shine they usually want to know:

What is Hydrocephalus?

Hydrocephalus occurs when the production of cerebro-spinal flu id (CSF) flowing around the brain and spinal cord is greater than the absorption. If the drainage pathways are obstructed, the fluid accumulates in the cerebral ventricles leading to

A typical ventricular shunt in situ


catheter brain CSF Valve

In some case, tubing may lead to the heart tubing to the a b d o m i n a l cavity

heart

Sometimes the headaches are increased in severity by flexing the neck or by depressing the flushing chamber of the valve. Palpating the valve is generally not useful for diagnosis. Visual acuity or visual fields may be reduced. A new or increasing squint (especially on looking upwards or laterally) is an early sign of raised intracranial pressure. New or increased nystagmus may be evident, but papilloedema may take a long time to develop. A raised blood pressure and slow pulse are seen only in the advanced stages of raised intracranial pressure.

If any of these signs are present or if there is sufficient doubt about the diagnosis, the patient should be referred to a neurosurgical unit for further investigation. NB A sudden fever or a minor head injury can upset the CSF balance in a patient with a shunt and lead to signs of an acute raised intracranial pressure.

VA shunt) or, more usually, into the abdominal cavity (ventriculo-peritoneal VP shunt). There are now many sorts of valves with varying degrees of sophistication. Some have programmable devices controlling the rate of flow of CSF; some have an anti-syphon device to reduce excessive drainage; some have anti bacterial catheters to prevent infection. Shunts are usually intended to stay in place for life, although alterations or revisions might become necessary from time to time. Although most shunts do function well, complications do sometimes arise.

Acute blockage of the shunt

The patient with an acute malfunction of the shunt usually presents with headaches, vomiting and dizziness, but these symptoms are variable. He may also have visual disturbances and diplopia, fits or losses of consciousness.

Cerebrum Lateral ventricles (One each side) containing CSF

Spinal cord

Choroid plexus Choroid plexus 3rd ventricle Pituitary gland Brainstem

Superior sagittal sinus (Major vein)Cerebellum

Chronic malfunction of the shunt

Chronic malfunction of the shunt can be almost symptom-free. Signs of a slow increase in intracranial pressure can occur gradually over a period of weeks, months or years and cause insidious changes, fatigue, and general malaise. The patient may experience intellectual deterioration, an increase in visuospatial perceptual problems, and disturbances of gait and motor function, which can progress to dementia and death. If your patient complains of slowly progressive deterioration, chronic shunt blockage should be considered.

Over-drainage

In the case of over-drainage,the shunt allows CSF to drain from the ventricles more quickly than it is produced. If this happens suddenly the ventricles in the brain collapse, tearing delicate blood vessels on the outside of the brain and causing subdural haematoma. This can be trivial or it can cause symptoms Similar to those of a stroke. The blood may have to be evacuated and in some cases, if this is not done, it may be a cause of epilepsy later. If the over-drainage is more gradual, the ventricles collapse gradually to become slit-like (‘slit ventricles’). This often interferes with

shunt function causing the opposite problem, high CSF pressure, to reappear, but unfortunately the slit ventricles do not always increase in size again, producing the situation where there is very high CSF pressure with headache, vomiting etc but very small ventricles on scan. The symptoms of over-drainage can be very similar to those of under-drainage, though there are important differences. Headaches, dizziness and fainting occur and are often worse after getting up from lying down, whereas the headaches, caused by high CSF pressure are often worse on waking, before rising in the morning. However, the best way to diagnose the problem, having recognised that one exists, is for a neurosurgeon to monitor the CSF pressure over 24 hours.

Over-drainage can be a difficult problem. There is no clear relationship between the type of valve (high or low pressure) or the brand, and over-drainage. A change of valve to a higher pressure cannot be relied upon to cure it, though it appears to do so in some cases. Studies have shown the use of an ‘anti-syphon device’, a small button inserted into the shunt tubing, will often solve the problem, but this does not always work. Some shunts have these built-in, but neurosurgical opinion varies as to whether they should be used. To change a valve


Ventriculo-peritoneal shunt infection

Infection of the ventriculo-peritoneal shunt usually presents within two to three months but almost always within 6-8 months after a shunt operation. It can present as a blockage of the distal catheter with signs of a raised intracranial pressure rather than as an infection.

There can be intermittent fever, vomiting and anorexia, with abdominal pain and tenderness over the distal catheter, which may imitate an acute appendicitis. Tenderness, swelling and erythema can extend up the catheter track.

Ventriculo-atrial shunt infection

Ventriculo-atrial shunt infection, presents as a very different condition from that of ventriculo-peritoneal shunt infection.

The patient can become ill within a few days of the shunt operation, with signs of infection, but often the symptoms may be minimal and go unnoticed for many months or even years. There may be general malaise, fatigue, anorexia, intermittent fevers, anaemia and splenomegaly, but no signs of blockage of the shunt.

pressure, it is necessary to remove the valve and insert another. The ‘programmable’ or adjustable shunt, is intended to allow adjustment of the working pressure of the valve without operation. The valve contains magnets that allow the setting to be changed by laying a second magnetic device on the scalp. This is undoubtedly useful where the need for a valve of a different pressure arises, but the adjustable valve is no less prone to over-drainage than any other and it cannot be used to treat this condition.

Patients with programmable shunts need to be aware that exposure to magnetic fields including MRI scanning may adjust the shunt pressure.

Shunt infection

Infection of the shunt is very difficult to diagnose, as the symptoms can be insidious and confusing. They vary according to the causal organism, and the route of insertion of the shunt - whether ventriculo-peritoneal or ventriculo-atrial. The infection is introduced at operation, and it is caused by a variety of simple organisms, which are usually present on the skin. Most cases are due to coagulase negative staphylococci.

Endoscopic Third Ventriculostomy (ETV)

This procedure is not suitable for all patients with hydrocephalus and is not available in all neuro-surgical centres. If ETV fails, symptoms of raised ICP will be demonstrated. (see shunt malfunction). For further information about this procedure, please contact Shine.

Your local district general hospital may not be familiar with the management of hydrocephalus, and a referral to a neurosurgical unit or telephone contact with the neurosurgical team will be the most appropriate line of action when faced with shunt or ventriculostomy malfunction.

Hydrocephalus and fits

Patients with Hydrocephalus sometimes have fits. The fits are not due to the hydrocephalic process itself but are usually associated with an underlying cause (meningitis, abnormal development of the brain, neonatal haemorrhage etc). As a general rule, fits in patients with hydrocephalus should be treated in the same way as those


If the infection remains undiagnosed, there may be early evidence of immune complex disease, with arthralgia and transient rashes. If a shunt infection is still unsuspected, this may lead to loin pain, and, occasionally, to oedema, haematuria (with proteinuria), signs of glomerulonephritis, or ‘shunt nephritis’.

Diagnosis of shunt infections and prevention of complications

Diagnosis of infection in VP shunts rest upon the timing of presentation after operation, and on any signs or symptoms as described above. Generally, if signs of shunt obstruction appear within 6-8 months of operation, infection should be suspected, but in any case the patient should be referred to a neurosurgeon for further investigation. Features of VA shunt infection are often misleading and not infrequently result in referral to an inappropriate specialist such as rheumatology, haematology or nephrology. A simple antibody test is available for those with suspected VA (but not VP) shunt infections.

Further advice is available from Shine about where tests can be done.

be unable to assess the width of a doorway or the height of a kerb, which can take on frightening proportions for them. They may have difficulties with patterns, shapes and words causing specific learning deficits. They often have difficulty in sequencing, with an inability to organise themselves to do simple tasks in the right order, which may make them appear feckless. They may have good long term memory but poor working memory. Information needs to be broken down into ‘small chunks’ and it may help for it to be written down so that your patient can refer to it later. These are characteristic tendencies but, if they are not understood, they can be exasperating.

Someone with hydrocephalus may not have the insight or strategies to cope with these aspects of their disability and consequently families often suffer greatly because this is not always understood. A referral to a neuropsychologist with an interest in hydrocephalus can be very useful to assess the patient’s difficulties and help find ways to cope.

Everyone with hydrocephalus should be encouraged to live as their peers do albeit with some adjustments. So, adults who are in work or people in education

that occur in children who do not have hydrocephalus. This will include referral to a paediatrician or neurologist.

In a patient already treated for fits, an urgent consultation with their specialist should be sought if the fits change in character or frequency.

A rise in intracranial pressure due to blockage of a shunt system may sometimes reduce the threshold for an epileptic attack in a patient already known to have epilepsy and as both an epileptic fit and blockage of shunt system may produce a deterioration in conscious level this can sometimes lead to confusion between the two.

If in doubt, consult the neurosurgeon treating the hydrocephalus.

Hydrocephalus - the hidden problems

People with hydrocephalus often appear very verbose. Unfortunately, this can mask any brain damage and subtle learning difficulties caused by the hydrocephalus. These are difficult to understand and easy to ignore or miss.

They may have spatial awareness problems which means that they may see things differently, and may

may need help with organisation, motivation or just finding their way around.

There are a few sports and activities that they are not advised to participate in - these will include ‘extreme sports’ such as bungee jumping, deep sea diving and some contact sports eg rugby scrums. A protective helmet should be worn only for those sports that require it.

If a child has a head injury, the parents should be reassured that the shunt is unlikely to be damaged: if in doubt, the neurosurgeon should be contacted for advice.

Children with hydrocephalus will usually be seen in the neurosurgical clinic on an annual basis: adults may not be seen routinely, but will

Help us

Shine relies on people’s generosity and support so we can help our clients who depend on us for help and advice - people with hydrocephalus, spina bifida, their families and carers. To donate to Shine please visit www.shinecharity.org.uk or call 01733 421329.

This information has been produced by Shine’s medical advisers and approved by Shine’s Medical Advisory Committee of senior medical professionals.

Shine - Registered charity no.249338To see our full range of information sheets and to find out how to donate to Shine please visit www.shinecharity.org.uk

have a pathway to follow if they have problems.

Both groups of patients need annual eye checks (by an optician).

Children with hydrocephalus should receive all the routine vaccinations offered to their peers. As some children with hydrocephalus have feeding problems a check on weight and diet should be part of their routine care.

Health & Medicine

Guidelines for General Practitioners