Hydrocephalus of the brain occurs when there is an imbalance in how
cerebrospinal fluid (CSF) is made and absorbed, or in
how it flows. One way to classify this condition is by how the imbalance
occurs. There are two main ways:
Nonobstructive, or communicating,
hydrocephalus occurs when the CSF flows out of the chambers of the brain (ventricles) and into
the spinal canal, but it is not reabsorbed normally by the tissue surrounding
the brain and spinal cord. Sometimes this type of hydrocephalus corrects
Obstructive, or noncommunicating,
hydrocephalus occurs when the CSF does not flow properly between or out of the
brain ventricles because of an obstruction, such as from a malformation or
In very rare cases the brain tissue makes too much CSF and the body
can't properly absorb or distribute the high amount of fluid. This is called
It is possible that the main title of the report Pontocerebellar Hypoplasia is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Cerebrospinal fluid sometimes builds up rapidly, such as with an
injury, and can cause sudden and severe damage if not treated. Other times the
fluid gradually accumulates and may not cause problems right away.
Types of hydrocephalus include:
Congenital hydrocephalus, which is
present at birth. Congenital hydrocephalus may be caused by physical problems
with how CSF flows or is made or absorbed, by infections or trauma during fetal
development, or by
teratogens. It may be linked with other birth
defects that affect the spine, especially open
neural tube defects.
hydrocephalus, which develops at the time of birth or later. It can be caused
by infections such as
meningitis, bleeding, injury, or a
Normal-pressure hydrocephalus, which usually develops in
people who are age 55 or older. It is a potentially treatable cause of
dementia. This type of hydrocephalus often occurs
after head trauma, infections, and bleeding within the
Ex-vacuo hydrocephalus, which occurs when there is damage to
the brain caused by
stroke or traumatic injury. This type of hydrocephalus
may not be a health danger for some people, in which case treatment is not
With all types of hydrocephalus, early detection and treatment are
important to minimize or prevent long-term problems.
In this article
This information is produced and provided by the National
Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National
Institute via the Internet web site at http://
.gov or call 1-800-4-CANCER.
WebMD Medical Reference from Healthwise
March 12, 2014
This information is not intended to replace the advice of a doctor.
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