CD-ROM Today (UK) (Spanish) 15/CDRT.iso/dp/0370/03705.txt

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$Unique_ID{BRK03705}
$Pretitle{}
$Title{Encephalocele}
$Subject{Encephalocele Cephalocele Craniocele Cranium Bifidum Bifid Cranium
Cranial Meningoencephalocele Anencephaly Hard plus/minus E Syndrome
Hydrocephalus Meckel Syndrome Spina Bifida}
$Volume{}
$Log{}

Copyright (C) 1992 National Organization for Rare Disorders, Inc.

867:
Encephalocele

** IMPORTANT **
It is possible that the main title of the article (Encephalocele) is not
the name you expected.  Please check the SYNONYMS listing to find the
alternate name and disorder subdivisions covered by this article.

Synonyms

     Cephalocele
     Craniocele
     Cranium Bifidum
     Bifid Cranium
     Cranial Meningoencephalocele

Information on the following diseases can be found in the Related
Disorders section of this report:

     Anencephaly
     Hard plus/minus E Syndrome
     Hydrocephalus
     Meckel Syndrome
     Spina Bifida

General Discussion

** REMINDER **
The Information contained in the Rare Disease Database is provided for
educational purposes only.  It should not be used for diagnostic or treatment
purposes.  If you wish to obtain more information about this disorder, please
contact your personal physician and/or the agencies listed in the "Resources"
section of this report.

Encephalocele is a rare disorder in which an infant is born with a gap in
the skull.  The membranes that cover the brain (meninges), and brain tissue,
protrude through this gap.  This disorder is probably caused by failure of
the neural tube to close during development of a fetus.

Symptoms

Encephalocele is characterized by a gap in the skull in which there is a
protrusion of the membranes that cover the brain (meninges) and brain tissue.
The protrusion is typically located along the midline of the bones that form
the sides of the skull (parietal), or the cuplike bone at the back of the
skull (occipital), or at the top of the nose between the eyes, or at the back
of the head.

When the encephalocele is not covered with skin, infection or swelling of
the membranes covering the brain may occur.  (For more information on
infections of the brain choose "Meningitis" as your search term in the Rare
Disease Database).  Improper handling of encephaloceles located in the nasal
area may also lead to meningitis.

Patients with an encephalocele may develop hydrocephalus.  Hydrocephalus
is characterized by an excess of spinal fluid in the head causing pressure in
the skull and widening of the ventricles (cerebral spaces) making the head
unusually large.  (For more information on this disorder choose
"Hydrocephalus" as your search term in the Rare Disease Database).

When an encephalocele is present on the back of the skull, it is often a
part of a disorder known as Meckel Syndrome.  Meckel Syndrome is a rare
inherited disorder which includes congenital deformities of the brain
resulting in mental retardation.  (For more information on this disorder
choose "Meckel" as your search term in the Rare Disease Database).

Incomplete closure of the roof of the mouth (cleft lip and/or palate), or
partial or complete absence of an area of the brain that connects the two
cerebral hemispheres (Agenesis of Corpus Callosum) have also been associated
with encephalocele.  (For more information on these disorders choose "Cleft
Lip and Cleft Palate" or "Agenesis of Corpus Callosum" as your search terms
in the Rare Disease Database).

Causes

The exact cause of Encephalocele is not known.  It is considered to be a
birth defect.

Failure of the tube of tissue that lies along the center of the early
embryo (neural tube) to close properly during fetal growth probably causes
the encephalocele to form.  Encephalocele is one type of neural tube defect.
The most well known neural tube defect is spina bifida.  (For more
information on this disorder choose "Spina Bifida" as your search term in the
Rare Disease Database).

The anticonvulsant drug valproic acid may cause neural tube defects when
taken by a pregnant women.

Affected Population

Encephalocele is a rare neural tube defect that affects male and female
infants in equal numbers.

Encephalocele occurs in an estimated 1 out of every 2,000 live births.
Ireland has the highest occurrence of encephalocele and Thailand has a high
percentage of frontal encephaloceles.

Related Disorders

Encephalocele may be a component of, or similar to, the following disorders.
Comparisons may be useful for a diagnosis:

Anencephaly is a rare birth defect characterized by the absence of the
two hemispheres of the brain.  The absent brain tissue is sometimes replaced
by abnormal cystic nerve tissue, which may be either exposed or covered with
skin.  Additionally, varying portions of the brainstem and spinal chord may
be missing or malformed.  This disorder can be inherited through autosomal
recessive genes.  (For more information on this disorder, choose
"Anencephaly" as your search term in the Rare Disease Database).

Hard plus/minus E Syndrome is an acronym for a combination of
Hydrocephalus, Agyria (smooth brain), and Retinal Dysplasia (an eye
condition).  This disorder is also known as HARD Syndrome, Warburg Syndrome,
Chemke Syndrome, Pagon Syndrome, Walker-Warburg Syndrome, Cerebroocular
Dysgenesis, or COD.  The "E" is for "encephalocele" when it occurs.

Hydrocephalus is a disorder characterized by an unusually large head.  It
is caused by the abnormal dilation of the ventricles (cerebral spaces) in the
brain and the obstruction of the spinal fluid passages (ventricular block) of
the central nervous system.  This accumulation of fluid puts excessive
pressure on the tissues of the brain, and causes an enlargement of the head.
Hydrocephalus may be congenital or acquired and if not treated early may
cause brain damage.  (For more information on this disorder, choose
"Hydrocephalus" as your search term in the Rare Disease Database).

Meckel Syndrome is a rare inherited syndrome.  Major symptoms may include
congenital deformities of the brain resulting in mental retardation.
Malformations of the hands and feet, and bone deformities of the arms and
legs may also occur.  In males genitals may fail to develop properly.
Kidney, pancreas and liver may also be abnormal.  (For more information on
this disorder, choose "Meckel" as your search term in the Rare Disease
Database).

Spina Bifida is a disorder in which there is an "open (or nonfused)
spine."  In spina bifida, one or more of the individual bones of the spine
fail to close completely, leaving a cleft or defect in the spinal canal.
Through such an abnormal opening, part of the contents of the spinal canal
can protrude or herniate.  The exact cause of spina bifida is not known.
(For more information on this disorder choose "Spina Bifida" as your search
term in the Rare Disease Database).

Therapies:  Standard

Surgical closure of the encephalocele is normally performed as soon as
possible.  For Encephaloceles affecting the face, several plastic surgeries
may be required over a period of time.

When Hydrocephaly is also present the insertion of a shunt or tube into
the head cavity drains the excess cerebrospinal fluid into a part of the body
that can absorb it.  In growing children the shunt may have to be lengthened
periodically.

When Bacterial Meningitis is present, it is usually treated with
different types of antibiotics depending on the bacteria involved.  The
addition of the drug dexamethasone to the antibiotic treatment can be helpful
in reducing meningeal inflammation.

Therapies:  Investigational

Scientists are studying the causes of neural tube defects in an attempt to
prevent them from occuring.  Researchers funded by the March of Dimes have
been studying the effects of drugs and chemicals on central nervous system
development.  They are studying how viruses, drugs, growth-promoters and
other agents in the earliest stages of a baby's development may influence the
way the nervous system grows.

Other investigators are looking for ways to drain fluid from the brain
without surgery.  They also are studying biochemical changes in parts of the
brain affected by hydrocephalus, with the hope of preventing possible brain
damage.

As a result of a large research project funded by the National Institutes
of Health, which is studying 55,000 mothers and their offspring, conditions
leading to abnormalities of the newborn are expected to be understood more
clearly in the future.

This disease entry is based upon medical information available through
April 1992.  Since NORD's resources are limited, it is not possible to keep
every entry in the Rare Disease Database completely current and accurate.
Please check with the agencies listed in the Resources section for the most
current information about this disorder.

Resources

For more information on Encephalocele, please contact:

     National Organization for Rare Disorders (NORD)
     P.O. Box 8923
     New Fairfield, CT  06812-1783
     [phone]

     National Hydrocephalus Foundation
     400 N. Michigan Ave., Suite 1102
     Chicago, IL  60611-4102

     Hydrocephalus Parent Support Group
     225 Dickinson St., H-893
     San Diego, CA  92103

     Hydrocephalus Association
     870 Market St., Suite 955
     San Francisco, CA  94102
     [phone]

     Fighters for Encephaly Support
     3032 Brereton Ave
     Pittsburgh, PA  15219
     [phone]

     National Craniofacial Foundation
     3100 Carlisle St., Suite 215
     Dallas, TX  75204
     [phone]
     (For neural tube defects affecting the face)

     Forward Face
     560 First Ave.
     New York, NY  10016
     [phone]
     (800) 422-FACE

     NIH/National Institute of Child Health and Human Development (NICHD)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]

     NIH/National Institute of Neurological Disorders & Stroke (NINDS)
     9000 Rockville Pike
     Bethesda, MD  20892
     [phone]
     [phone]

For Genetic Information and Genetic Counseling Referrals:

     March of Dimes Birth Defects Foundation
     1275 Mamaroneck Avenue
     White Plains, NY 10605
     [phone]

     Alliance of Genetic Support Groups
     35 Wisconsin Circle, Suite 440
     Chevy Chase, MD  20815
     (800) 336-GENE
     [phone]

References

BIRTH DEFECTS ENCYCLOPEDIA, Mary Louise Buyse, M.D., Editor-In-Chief;
Blackwell Scientific Publications, 1990.  Pp. 614-15.

INTERIM CDC RECOMMENDATIONS FOR FOLIC ACID SUPPLEMENTATION FOR WOMEN-
AUGUST 1991:  Center for Disease Control; JAMA (September 4, 1991, issue
266(9)).  Pp. 1191.

NASAL MIDLINE MASSES IN INFANTS AND CHILDREN.  DERMOIDS, ENCEPHALOCELES,
AND GLIOMAS:  A.S. Paller, et al.; Arch Dermatol (March, 1991, issue 127(3)).
Pp. 362-6.

SUBTORCULAR OCCIPITAL ENCEPHALOCELES.  ANATOMICAL CONSIDERATIONS RELEVANT
TO OPERATIVE MANAGEMENT:  P.H. Chapman, et al.; J Neurosurg (September, 1989,
issue 71(3)).  Pp. 375-81.

NASAL ENCEPHALOCELE:  DEFINITIVE ONE-STAGE RECONSTRUCTION:  L.A. Sargent
et al.; J Neurosurg (April, 1988, issue 68(4)).  Pp. 571-5.

CEPHALOCELES:  CLASSIFICATION, PATHOLOGY, AND MANAGEMENT:  D.J. David et
al.; World J Surgery (July-August, 1989, issue 13(4)).  Pp. 349-57.