Hydrocephalus occurs when there is an excess of cerebrospinal fluid (CSF) in the brain. CSF functions as a cushion around the brain within the skull cavity and prevents it from direct structural impact while maintaining buoyancy. In normal circumstance, CSF flows in “water tanks” inside the brain and gets absorbed into the blood.
There are 2 kinds of hydrocephalus:
- Obstructive hydrocephalusis caused by a block in the CSF flow
- Communicating hydrocephalusoccurs when CSF flow is unobstructed, but there is either overproduction of CSF or failure in CSF reabsorption.
Picture source: The ISPN Guide to Pediatric Neurosurgery
Keeping the above in mind, it is possible to come to a diagnosis and treatment for hydrocephalus. Obstructive hydrocephalus is usually caused by tumours or lesions that mechanically block the CSF pathway. Communicating hydrocephalus is mostly caused by infections, however it can also be due to tumours that increase CSF production. When an infection is suspected, a lumbar puncture is performed to obtain a sample of CSF which can confirm the diagnosis.
It is important to know that hydrocephalus can affect both adults and children; new born babies are also not spared.
In adults, the skull acts like a rigid helmet that does not tolerate an increase in CSF volume, resulting in elevated pressure to the brain. Symptoms reflecting this are:
- Frequent or persistent headaches, especially early in the morning
- Vomiting
- Decreased mental or cognitive abilities
In severe cases, hydrocephalus can result in seizures, impaired consciousness, coma and even death.
Although headaches are more likely due to tension headaches or migraine, an unrelenting headache can be a “warning sign” of something more serious.
Things are slightly different for the paediatric population. In most children, the skull only fuses by age 3 or 4. However, children who develop hydrocephalus without complete closure or fusion of the skull may have the following:
- Head that is gradually growing bigger
- Wider gaps between skull bones
- Dilated blood vessels over the scalp and forehead
- Eyes always looking downwards
In babies or young children, hydrocephalus can cause physical and mental developmental issues. Some children have heads so big that they are unable to lift them up.
If hydrocephalus is suspected, a CT or MRI scan of the head is required. If the scan does not show any obvious structural lesions, a lumbar puncture is performed to obtain CSF for analysis. The treatment for hydrocephalus is aimed at removing the cause with temporary diversion of CSF. Unfortunately in certain cases, hydrocephalus is persistent and permanent diversion is needed.
It is important to recognise signs of increased intracranial pressure that may be due to hydrocephalus in order to obtain timely diagnosis and early treatment. If in doubt, consult a trusted doctor.
Dr Vinodh Vayara Perumall is a neurosurgical medical officer whose passion for neurosurgery has brought him all the way from Perak to Sabah.
[This article belongs to The Malaysian Medical Gazette. Any republication (online or offline) without written permission from The Malaysian Medical Gazette is prohibited.]