Hydrocephalus
Background
Hydrocephalus is commonly, but inaccurately, known as 'water on the brain.' A watery fluid known as Cerebro Spinal Fluid (CSF) flows through narrow passageways in the brain from one ventricle to the next, out over the inside of the brain and down the spinal cord. CSF is continuously absorbed into the blood stream and the amount of pressure is kept within a narrow range. If the flow of fluid is obstructed at any point, it accumulates in the ventricles causing them to enlarge and compress surrounding brain tissue. In babies - but not older children or adults - the head will enlarge.