hydrocephalus

hydrocephalus An abnormal buildup of cerebrospinal fluid (CSF) in the ventricles and/or subarachnoid space of the brain. The fluid often increases intracranial pressure, which can compress and damage the brain. Hydrocephalus can arise before birth or at any time afterward. Causes can include birth defects (particularly spina bifida), hemorrhage into the brain, infection, meningitis, tumor, and head injury. Symptoms depend on the person’s age. In infants, the most obvious sign is usually an abnormally large head; other symptoms may include vomiting, sleepiness, irritability, an inability to look upward, and seizures. In older children and adults, there is no head enlargement from hydrocephalus, but symptoms may include headache, nausea, vomiting, and sometimes blurred vision. Patients may have problems with balance, delayed development in walking or talking, and poor coordination. Irritability, fatigue, seizures, and personality changes (such as an inability to concentrate or remember things) may also develop. Drowsiness and double vision are common symptoms as hydrocephalus progresses. Treatment involves insertion of a shunt to let the excess fluid exit and be reabsorbed into the bloodstream, thereby relieving the pressure on the brain. The outlook with hydrocephalus depends on the cause and on the timing of the diagnosis and treatment. Also known as water on the brain and hydrocephaly. See also hydrocephalus, acquired; hydrocephalus, congenital.