Hydrocephalous

Brain scans are used to diagnose hydrocephalus (excess fluid in the brain).

Congenital and acquired hydrocephalus

CT scans and MRI scans are often used in combination to confirm a diagnosis of hydrocephalus present from birth (congenital) and hydrocephalus that develops later in children and adults (acquired).

These scan the brain in detail. They can show the build-up of fluid in the brain and the increased pressure, as well as highlighting any structural defects that may be causing the problem.

Sometimes congenital hydrocephalus is detected before birth, during a pregnancy ultrasound scan.

Normal pressure hydrocephalus

Normal pressure hydrocephalus (NPH) can be difficult to diagnose because the symptoms start gradually and are similar to those of more common conditions, such as Alzheimer's disease.

It's important to make a correct diagnosis because, unlike Alzheimer’s disease, the symptoms of NPH can be relieved with treatment.

Your doctors will assess:

how you walk (your gait)

your mental ability

symptoms that affect your bladder control, such as urinary incontinence

the appearance of your brain (using scans)

NPH may be diagnosed if you have difficulty walking, mental and bladder problems, and cerebrospinal fluid (CSF) levels that are higher than usual. However, you may not have all these symptoms.

Further tests may also be done to decide whether you would benefit from having surgery, such as a:

lumbar puncture

lumbar drainage test

lumbar infusion test

Lumbar puncture

A lumbar puncture is a procedure where a sample of CSF is taken from your lower spine. The pressure of the CSF sample is then checked.

Removing some CSF during a lumbar puncture may help improve your symptoms. If it does, you may benefit from having surgery (see treating hydrocephalus to find out more).

Lumbar drainage test

You may have a lumbar drain if a lumbar puncture does not improve your symptoms.

Under local anaesthetic, a tube is inserted between the bones in your spine (vertebra) to drain a large amount of CSF. This is done over a few days, to see whether your symptoms improve.

Lumbar infusion test

During a lumbar infusion test, fluid is slowly injected into the lower part of your spine while measuring the pressure.

Your body should absorb the extra fluid and the pressure should stay low. If your body cannot absorb the extra fluid, the pressure will rise, which could indicate NPH and that surgery will be helpful.

Hydrocephalus (excess fluid in the brain) is treated with surgery.

Babies who are born with hydrocephalus (congenital) and children or adults who develop it (acquired hydrocephalus) usually need prompt treatment to reduce the pressure on their brain. 

If hydrocephalus is not treated, the increase in pressure will cause brain damage.

Both congenital and acquired hydrocephalus are treated with either shunt surgery or neuroendoscopy.

Shunt surgery

During shunt surgery, a thin tube called a shunt is implanted in your brain. The excess cerebrospinal fluid (CSF) in the brain flows through the shunt to another part of your body, usually your tummy. From here, it's absorbed into your blood.

Inside the shunt there's a valve that controls the flow of CSF, so it does not drain too quickly. You can feel the valve as a lump under the skin on your scalp.

The operation

Shunt surgery is done by a specialist in brain and nervous system surgery (neurosurgeon). It's done under a general anaesthetic and usually takes 1 to 2 hours.

You may need to stay in hospital for a few days after the operation to recover.

If you have stitches, they may dissolve or need to be removed. Some surgeons use skin staples to close the wound, which will need to be removed after a few days.

After the shunt has been installed, further treatment for hydrocephalus may be needed if the shunt becomes blocked or infected. Shunt repair surgery will then be necessary.

Endoscopic third ventriculostomy (ETV)

An alternative procedure to shunt surgery is an endoscopic third ventriculostomy (ETV).

Instead of inserting a shunt, the surgeon makes a hole in the floor of your brain to allow the trapped cerebrospinal fluid (CSF) to escape to the brain's surface, where it can be absorbed.

ETV is not suitable for everyone, but it could be an option if the build-up of CSF in your brain is caused by a blockage (obstructive hydrocephalus). The CSF will be able to drain through the hole, avoiding the blockage.

The operation

ETV is done under general anaesthetic. The neurosurgeon makes a small hole in your skull and brain, and uses an endoscope to look inside the chambers of your brain. An endoscope is a long, thin tube with a light and camera at one end.

After making a small hole in the floor of your brain to drain the fluid, the endoscope is removed and the wound is closed using stitches. The procedure takes around 1 hour.

There's less risk of infection after ETV than with shunt surgery. However, as with all surgical procedures, there are some risks.

Read more about the complications of hydrocephalus.

The long-term results of ETV are similar to those for a shunt operation. As with shunts, there's a risk of a blockage happening months or years after surgery, which will cause your symptoms to return.

Normal pressure hydrocephalus (NPH)

Normal pressure hydrocephalus (NPH), which usually affects older people, can sometimes be treated with a shunt. However, not everyone with NPH will benefit from shunt surgery.

As there's a risk of complications with shunt surgery, you'll need tests to assess whether the potential benefits of surgery outweigh the risks.