Hydrocephalus implies water on the brain. It is illustrated by an excess accumulation of cerebrospinal fluid (CSF) around the brain within the skull. This extreme collection of fluid within the inadequate space of the bony skull conveys pressure on the brain and brings about impairment to the brain tissue. It particularly appears in children however may also arise in adults and older people. It can occur due to birth defect, genetic defect, infection of the central nervous system, injury or tumors of the brain or spine. The diagnosis can be verified by CT scan of the head. Additional imaging tests such as skull X-rays, brain scan, ultrasound and arteriography may likewise be exercised. Occasionally lumbar puncture and assessment of the cerebrospinal fluid is also performed.

Treatment is targeted at refining the stream of the cerebrospinal fluid from the brain. It is treated surgically by directing the brain fluid to supplementary parts of the body such as abdominal cavity by positioning a flexible plastic tube called a shunt from the brain to that area where it is to be absorbed. Complications that may occur include the shunt becoming impassable, separated, or infected.

A substitute surgical procedure is called third ventriculostomy. Third ventriculostomy is performed by the surgeon utilizing images from an endoscope, a pen-sized slim device with an enclosed camera that directs images onto the screen. The surgery comprises creating a small hole in the floor of the third ventricle thus bypassing the location of hindrance into a region where the CSF can be reabsorbed.