National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Congenital hydrocephalus

Congenital hydrocephalus is when a child is born with an excessive accumulation of cerebrospinal fluid (CSF) in the brain. CSF is a clear fluid that surrounds the brain and spinal cord. This excess fluid causes an abnormal widening of spaces in the brain called ventricles (ventriculomegalia) and can create a harmful pressure on brain tissue.[1] Symptoms of hydrocephalus vary and may include an unusually large head with thin, transparent scalp, bulging forehead with increased spaces between the bones of the skull (fontanelles), and a downward gaze. Other symptoms may include seizures, abnormal reflexes, slow heartbeat and respiratory rate, headaches, vomiting, irritability, weakness, and visual problems.[1][2][3] 

It is caused by genetic and non-genetic factors. The most common cause of congenital hydrocephalus are variations (mutations) in the  L1CAM gene, where there is a narrow passageway between the third and fourth ventricles (aqueductal stenosis). Other causes include mutations in many other genes, brain and/or spinal cord malformations, infections, bleeding inside the cavities of the brain (intraventricular hemorrhage), trauma, exposition to certain drugs (teratogens) or a congenital tumor of the brain.[1][3] Congenital hydrocephalus can be an isolated malformation or be part of a syndrome where there are other associated malformations.[1] It is most often treated by surgically inserting a shunt system to transport the excess CSF and allow for re-absorption. If left untreated, blindness and continuing mental deterioration may occur.[1][2][3] 

Hydrocephalus may be subdivided according to the particular defect that exists in the brain and whether the cerebrospinal fluid pressure is high or normal:[1][4]

  • Communicating hydrocephalus is when there is no blockage (obstruction) in the ventricules but the fluid is not absorbed readily, or there is too much fluid  to be absorbed. 
  • Noncommunicating (obstructive) hydrocephalus is when there is a blockage of the CSF causing widening (dilation) of the pathways that are located upstream of the block, resulting in an increased  pressure inside the brain. 
There are also 2 other forms of hydrocephalus that usually affect only adults:[1][4]
  • Normal-pressure hydrocephalus is where the ventricules are expanded but the pressure inside the nervous system is normal. 
  • Hydrocephalus ex-vacuo occurs when stroke or traumatic injury cause damage to the brain and the brain tissue may shrink. 
Hydrocephalus may also be classified in congenital or acquired. Acquired hydrocephalus develops at the time of birth or at some point afterward and may be caused by injury or disease.[1][5]
Last updated: 1/30/2018

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Hydrocephalus
Too much cerebrospinal fluid in the brain
0000238
30%-79% of people have these symptoms
Bulbous nose 0000414
Colpocephaly 0030048
Downslanted palpebral fissures
Downward slanting of the opening between the eyelids
0000494
Facial asymmetry
Asymmetry of face
Crooked face
Unsymmetrical face
[ more ] 		0000324
Frontal bossing 0002007
Intellectual disability
Mental deficiency
Mental retardation
Mental retardation, nonspecific
Mental-retardation
[ more ] 		0001249
Iris coloboma
Cat eye
0000612
Macrocephaly
Increased size of skull
Large head
Large head circumference
[ more ] 		0000256
Motor delay 0001270
Posteriorly rotated ears
Ears rotated toward back of head
0000358
Seizure 0001250
Small cerebral cortex 0002472
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ] 		0000486
Ventriculomegaly 0002119
1%-4% of people have these symptoms
Abnormal heart morphology
Abnormality of the heart
Abnormally shaped heart
Heart defect
[ more ] 		0001627
Lissencephaly
Fewer or absent grooves in brain
0001339
Macular hypoplasia 0001104
Optic atrophy 0000648
Sensorineural hearing impairment 0000407
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Last updated: 7/1/2020

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • ClinicalTrials.gov lists trials that are related to Congenital hydrocephalus. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Congenital hydrocephalus. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know.

  1. Hydrocephalus Fact Sheet. NINDS. April 5, 2016; http://www.ninds.nih.gov/disorders/hydrocephalus/detail_hydrocephalus.htm.
  2. Hydrocephalus. MedlinePlus. 6/13/2016; https://www.nlm.nih.gov/medlineplus/hydrocephalus.html.
  3. Haridas A & Tomita T. Hydrocephalus in children: Physiology, pathogenesis, and etiology. UpToDate. January 8, 2018; https://www.uptodate.com/contents/hydrocephalus-in-children-physiology-pathogenesis-and-etiology.
  4. Hydrocephalus. National Organization for Rare Diseases (NORD). 2007; https://rarediseases.org/rare-diseases/hydrocephalus/.
  5. treatment of hydrocephalus. National Hydrocephalus Foundation. 2014; http://nhfonline.org/treatment-of-hydrocephalus.htm.