What is Hydrocephalus?

Hydrocephalus is an abnormal accumulation of cerebrospinal fluid (CSF) within cavities in the brain called ventricles. Cerebrospinal fluid is produced in the ventricles and in the choroid plexus. It circulates through the ventricular system in the brain and is absorbed into the bloodstream. This fluid is in constant circulation and has many functions, including to surround the brain and spinal cord and act as a protective cushion against injury. It contains nutrients and proteins necessary for the nourishment and normal function of the brain, and carries waste products away from surrounding tissues.

Hydrocephalus occurs when there is an imbalance between the amount of CSF that is produced and the rate at which it is absorbed. As the CSF builds up, it causes the ventricles to enlarge and the pressure inside the head to increase. A shunt was placed into Gage's brain at 12 hours old to drain this excess fluid into the stomach cavity. Shunt malfunctions are very common and require continued maintenance, resulting in further surgery and regular hospital visits.