What is hydrocephalus in elderly people?

Hydrocephalus ("water on the brain") is an excess of cerebrospinal fluid around the brain. Typically, the ventricles (cavities in the center of the brain) that secrete this fluid are greatly enlarged. Spinal fluid  circulates around the spinal cord and is absorbed by veins on the external surface of the brain. Congenital hydrocephalus is usually diagnosed shortly after birth, but normal-pressure hydrocephalus occurs in a small number of elderly people. This condition can result from head trauma, brain hemorrhage, or meningitis (inflammation of the membrane covering the brain), but most cases occur spontaneously without an obvious preceding illness.

In addition to developing dementia, people with this condition lose bladder control and walk in a slow, hesitant manner, as if their feet are stuck to the floor. A surgically implanted tube (shunt) that drains fluid from a cavity in the brain (the lateral ventricle) to the jugular vein or to the abdomen brings rapid improvement, provided treatment is started soon after the symptoms appear.