What is hydrocephalus?
The brain and spine are hollow and contain fluid known as cerebro-spinal fluid (CSF). The cavities in the brain containing the fluid are known as ventricles.
This fluid also surrounds the brain and spine. The CSF protects the brain from impact on the skull and also nourishes the brain. The adult brain produces around 500 ml of fluid per day, however the capacity for the fluid in the brain is only 125 ml. Thus the fluid is produced and circulates around the brain and then is reabsorbed into the blood. The brain keeps the situation of fluid production and re-absorption in balance so that there is a constant amount of fluid around the brain. Any mechanism which disrupts this balance can cause too much fluid within the brain. This is known as hydrocephalus. In general terms hydrocephalus can occur when too much fluid is produced, the circulation of fluid is blocked, or not enough fluid is reabsorbed into the bloodstream.