Hydrocephalus is a disorder that involves the accumulation of fluid in and surround the brain. A natural byproduct of normal brain function is the creation of cerebral spinal fluid (CSF). Under normal circumstances the brain reabsorbs CSF as fast as it is created. The continuous creation and reabsorption of CSF lead to its steady state CSF in the head at any given time. Hydrocephalus occurs when there is an imbalance between the rate of absorption and creation of CSF, thus leading to an accumulation of fluid and pressure.