Patient Guide · Hydrocephalus
Hydrocephalus — Information for Patients, Parents and Families
Hydrocephalus is a build-up of cerebrospinal fluid within the brain's ventricles. It can affect anyone from unborn babies to older adults — and it is treatable.
The basics
What is hydrocephalus?
Cerebrospinal fluid, or CSF, is a clear fluid that cushions the brain and spinal cord, carries nutrients, and removes waste. Hydrocephalus develops when CSF cannot circulate or be absorbed normally, and builds up within the ventricles instead — placing pressure on the brain and interfering with normal function. Some patients develop symptoms rapidly and need urgent treatment; others develop them gradually over months or years.
What causes it
Common causes
Congenital
A narrowed cerebral aqueduct, spina bifida, or another abnormality affecting CSF circulation present from birth.
Bleeding
Haemorrhage within or around the brain, including intraventricular haemorrhage related to prematurity.
Infection
Meningitis or another brain infection can scar the pathways that normally allow CSF to circulate and be absorbed.
Mass or injury
A brain or spinal tumour, a cyst, head injury, or previous brain surgery can each obstruct or disrupt CSF flow.
In some patients, particularly those with normal-pressure hydrocephalus, no definite cause is ever identified.
Recognising it
Symptoms by age
Babies
A rapidly increasing head circumference, a tense or bulging fontanelle, prominent scalp veins, downward-looking eyes, irritability, poor feeding, vomiting, and excessive sleepiness.
Older children
Morning headache, nausea, blurred or double vision, difficulty looking upwards, balance problems, decline in school performance, and changes in behaviour.
Adults
Persistent or worsening headache, worse in the morning, blurred vision, increasing sleepiness, confusion, memory difficulty, and trouble walking or maintaining balance.
Normal-pressure hydrocephalus
Older adults — a triad of walking difficulty, cognitive slowing, and bladder disturbance, developing gradually and often mistaken for Parkinson's or Alzheimer's disease.
Making the diagnosis
How it's diagnosed
Diagnosis combines a detailed history, neurological examination, and imaging — usually a CT or MRI scan, sometimes with an assessment of how CSF is flowing. In babies, head circumference is measured over time; in children, development is assessed; in suspected NPH, formal walking and memory tests are added, along with a lumbar puncture or a period of temporary drainage to help predict who will benefit from a shunt.
Your options
Treatment options
Endoscopic third ventriculostomy (ETV)
A small camera creates a new opening in the floor of the third ventricle, letting CSF bypass an obstruction through a natural pathway. No permanent tubing is implanted. Best suited to obstructions within the ventricular system, such as aqueductal stenosis.
Ventriculoperitoneal (VP) shunt
A system of narrow tubes and a valve diverts excess CSF from a brain ventricle to the abdominal cavity, where it is absorbed naturally. Suitable for most causes of hydrocephalus, and the more established option when ETV is not appropriate.
Temporary external drainage
Some patients need CSF drained externally before a permanent treatment is chosen — for example after a bleed or infection, while the situation stabilises.
Both operations carry real risks, from infection to failure requiring further surgery — your surgeon will explain which fits your situation.
When to worry
Signs of shunt or ETV failure
Attend the Emergency Department immediately if you notice
- Severe or rapidly worsening headache, with repeated vomiting
- Increasing drowsiness or difficulty waking
- New confusion, weakness, or seizure
- Sudden visual deterioration
- A tense or bulging fontanelle, or rapid enlargement of a baby's head
- Clear fluid leaking from a wound, or redness and swelling over a shunt with fever
Both ETVs and shunts can fail months or years after apparently successful treatment — don't wait for a routine appointment if these develop.
What to remember
Key clinical pearls
- 1Symptoms and their pace depend heavily on age — a baby's skull can still expand, while an adult's cannot, so presentations look very different.
- 2Not every patient with enlarged ventricles needs surgery — the decision rests on symptoms, imaging, cause, and likelihood of benefit.
- 3ETV avoids permanent shunt hardware but can fail, sometimes years later — lifelong awareness of the warning signs still matters.
- 4A shunt is a mechanical device and may need revision at any point in a patient's life, including as children grow.
- 5Previous symptoms often return in the same pattern when a shunt blocks or an ETV closes — patients and families learn to recognise their own warning signs.
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