Hydrocephalus is a condition in which the cerebrospinal fluid (CSF) accumulates within the brain and is common in infants and older adults. The accumulated fluid causes increased pressure inside the skull. Older people may have headaches, double vision, poor balance, urinary incontinence, personality changes, or mental impairment. It is characterized by head enlargement in infants. Adults and older children experience headache, impaired vision, cognitive difficulties, loss of coordination and incontinence. Treatment involves a tube inserted surgically into a ventricle to drain excess fluid.