Type of disease: Rare conditions
Hydrocephalus is a condition characterized by excessive accumulation of fluid in the brain. Although it was once known as "water on the brain," the "water" is actually cerebrospinal fluid (CSF) - clear fluid that surrounds the brain and spinal cord. Excess CSF builds up when it cannot drain from the brain due to a blockage in a passage through which the fluid normally flows. This excess fluid causes an abnormal widening of spaces in the brain called ventricles; this can create harmful pressure on brain tissue. Symptoms vary with age, disease progression, and individual differences in tolerance to the condition. Hydrocephalus may be congenital (present at birth) or acquired. The causes are not fully understood; it may result from inherited genetic abnormalities or developmental disorders; complications of premature birth; diseases such as meningitis; tumors; traumatic head injury; or other causes. It is most often treated by surgically inserting a shunt system. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.