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Genetic and Rare Diseases Information Center (GARD)

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Other Names for this Disease
  • Hydrocephaly
  • Ventriculomegaly
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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.[1]
Last updated: 8/22/2011


  1. Hydrocephalus Fact Sheet. NINDS. April 29, 2011; Accessed 8/19/2011.
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Basic Information

In Depth Information

  • Medscape Reference provides information on this topic. Click on the link to view this information. You may need to register to view the medical textbook, but registration is free.
  • The Online Mendelian Inheritance in Man (OMIM) is an catalog of human genes and genetic disorders. Each entry has a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine. 
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Hydrocephalus. Click on the link to view a sample search on this topic.