Hydrocephalus is a medical condition where cerebrospinal fluid (CSF) builds up on the brain. This fluid surrounds the brain and spinal cord and protects the brain, helping remove waste and deliver nutrients. However, when too much fluid builds up, it can cause pressure on the brain. The pressure from the build-up can lead to physical and cognitive difficulties, and if it isn’t treated it can cause serious, sometimes life-threatening complications. Some of the reasons that CSF can build up include spina bifida, premature birth, meningitis, brain tumours and traumatic head injuries.
Hydrocephalus can affect people of all ages, from babies to older adults. There are three commonly recognised types:
- Congenital, this is present at birth due to developmental issues.
- Acquired, develops after birth due to injury, infection, or tumours.
- Normal pressure (NPH), commonly in older adults, often characterised by a gradual build-up of fluid.
Hydrocephalus is not widely discussed and you might be more familiar with it as ‘water on the brain’, an older name for the condition. We think it is important to raise awareness, as it is a lot more common than many realise. It is estimated that one in every 770 babies born in the UK each year will develop hydrocephalus,- and many others develop the condition later in life, perhaps due to illness or serious injury.
Acquired hydrocephalus
Acquired hydrocephalus develops after birth and can be caused by brain injury, infection, tumours, and meningitis. It results from an event or condition that interferes with the normal flow of absorption of cerebrospinal fluid, leading to the build-up and generating an increased pressure on the brain.
If acquired hydrocephalus is left untreated, the pressure can result in life-threatening complications which often extend far beyond the initial problem. While the primary cause such as an infection or tumour may be managed or resolved, acquired hydrocephalus introduces an ongoing risk to brain function and overall health. In such events, symptoms can become persistent and gradually worsen, requiring urgent and targeted treatment.
Infection
Certain infections can interfere with the brain’s ability to circulate and absorb CSF. When the tissues surrounding the brain become inflamed, the normal pathways for fluid movement can be disrupted, allowing fluid to build up and increase pressure on the brain.
Meningitis
One of the most common infection-related causes is meningitis. This condition causes inflammation of the membranes surrounding the brain and spinal cord. In some cases, the inflammation can lead to scarring of brain tissue, which blocks or restricts the flow of CSF and contributes to the development of hydrocephalus.
Head injuries
Traumatic head injuries can also lead to acquired hydrocephalus. Injuries such as those sustained in accidents, falls, or sports incidents may cause bleeding, swelling, or damage to brain tissue. This can interfere with the normal flow or absorption of cerebrospinal fluid (CSF), resulting in a build-up of fluid within the brain. In some cases, hydrocephalus may develop shortly after the injury, while in others it can occur weeks or months later as the brain heals and scar tissue forms. Because of this, individuals who have experienced a significant head injury may require ongoing monitoring for symptoms such as headaches, balance problems, or changes in memory and concentration.
Brain tumours
Brain tumours can also cause acquired hydrocephalus by physically blocking the pathways through which CSF normally flows. Tumours may also cause swelling in surrounding brain tissue, further restricting fluid movement. This blockage can lead to a build-up of fluid and increased pressure inside the skull. Common symptoms associated with this include headaches, nausea, and cognitive difficulties.
As March has the status of being both Brain Tumour Awareness Month and home to Hydrocephalus Awareness Week, it is important to recognise that hydrocephalus is a complication that can sometimes arise from brain tumours, highlighting the need for early diagnosis and ongoing neurological care.
Signs and symptoms of hydrocephalus
Hydrocephalus symptoms will vary depending on a person’s age or how quickly the fluid builds up, but this guide features the most common warnings to look for.
Babies and young children will often show signs of the following:
- Rapid head growth
- A soft spot on the top of the head that appears swollen
- Vomiting/ feeding difficulties
- Unusual sleepiness or irritability
- Downward gaze of the eyes
Whilst adults and older children often show signs of:
- Persistent headaches
- Nausea or vomiting
- Balance issues or walking difficulties
- Blurred vision
- Memory difficulties or confusion
It is common for these symptoms to overlap with other conditions, meaning hydrocephalus is sometimes misdiagnosed or identified later than it should be.
Diagnosis and treatment
Doctors usually diagnose congenital and acquired hydrocephalus using CT scans and MRI scans, for both hydrocephalus present at birth and when it develops later in children or adults. This will reveal whether there is a build-up of fluid and if ventricles have become enlarged.
Normal pressure hydrocephalus (NPH) is more difficult to diagnose, the symptoms gradually start and have very similar feature to common conditions, often Alzheimer’s disease. Unlike many other conditions, there is relief for NPH. Doctors will often conduct further tests to decide whether further surgery is necessary, including lumbar puncture, lumbar drainage, or lumbar infusion tests.
Early diagnosis is important, like many other conditions, early intervention can prevent further damage to the brain.
Although hydrocephalus cannot currently be cured, it can be managed with treatment. The most common treatment is surgery to insert a shunt system. A shunt is a small flexible tube that drains excess fluid away from the brain and redirects to another part of the body, usually your stomach, where it is absorbed safely into the blood to relieve pressure and prevent further build up.
Another treatment is an endoscopic third ventriculostomy. Instead of inserting a shunt, a hole is made in the floor of the brain which allows a pathway for fluid to drain from the brain without the need for a shunt.
Who can provide support for living with hydrocephalus?
Hydrocephalus is a lifelong condition, but with appropriate awareness to get individuals medical care and support, it is possible for people to go on to live active and fulfilling lives. Many families and patients rely on ongoing support from organisations, such as Shine. We are proud to work alongside Shine in raising awareness of hydrocephalus and supporting people who are affected by the condition.