Hydrocephalus is a condition which quite literally means water on the brain. The water in question is in fact cerebrospinal fluid (CSF), a clear, colourless fluid which is made in constant quantity of about 500 ml each day. It bathes the brain and spinal cord, as well as their being fluid spaces within the brain which are occupied by CSF (the ventricles).
CSF is produced within the ventricles and then flows through a specific route within the brain to reach the brain surface from where it is absorbed away back into the bloodstream. Hydrocephalus can result either when there is a blockage to the flow of the CSF through the various channels in the brain or where there is a mismatch between the production and absorption. The former is referred to as obstructive or non-communicating hydrocephalus and the latter as communicating hydrocephalus.
Obstructive hydrocephalus is usually a mechanical issue and can be caused due to distortion of the brain anatomy, for example with some tumours. Communicating hydrocephalus on the other hand is usually due to impaired absorption of CSF and most commonly this happens after a bleed within the brain or an infection within the brain.
The symptoms of hydrocephalus are those of raised pressure inside the head. These include headache, drowsiness, nausea and vomiting, unsteadiness, blurring of vision and cognitive impairment. These symptoms can occur in a variety of other far commoner conditions, and it is very rare that they will be indicative of a new diagnosis of underlying hydrocephalus.
They treatment of hydrocephalus will largely be determined on the type of hydrocephalus and this is dealt with in greater detail in the hydrocephalus treatment page.