Most frequently linked to an infection, inflammation of the meninges (fine membranes covering the brain) which is called meningitis causes changes in the structures which allow resorption of CSF.

As this fluid is no longer drained naturally, it builds up and causes high intracranial blood pressure.

Once the meningitis has been cured, the normal CSF resorption process is not always restored and it may be essential for a shunt to remain in place.