Brain Surgery-Hydrocephalus

Also known as "water on the brain," hydrocephalus is one of the most frequently seen problems in a busy pediatric neurosurgical practice. The term "water on the brain" is actually more of a misnomer. In reality most cases of hydrocephalus represent a build up of spinal fluid inside the brain. Everyone produces spinal fluid inside their brains every minute of their lives. This fluid is very similar to the liquid portion of blood and contains various salts and products such as sodium and glucose. The fluid is primarily produced in connected chambers within the brain known as ventricles. The fluid volume produced in an adult is about equal to one pint per day. This fluid then circulates through the ventricles and around the brain and spinal cord. Eventually it is reabsorbed over the surface of the brain into large veins which carry the fluid back to the heart. This orderly cycle of spinal fluid production, flow and absorption maintains a protective environment to the nervous system. In addition, there is no loss of fluids or the salts contained in the spinal fluid.

Hydrocephalus is that state in which something has occurred to prevent this orderly procession of events. If this occurs, there is a relative build up of spinal fluid in the brain which can lead to injury or even death if not treated. It is very important to realize that hydrocephalus is the result of some event on the nervous system and that a child's prognosis is not so much based on the hydrocephalus as the cause of the hydrocephalus. While many cases have no clear cause, the following have been associated with the development of hydrocephalus; bleeding, infection, trauma, tumors, vascular problems, and structural problems. Some occur during pregnancy and others after birth. In addition, a small number can be transmitted genetically.