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$Unique_ID{BRK04309}
$Pretitle{}
$Title{Vascular Malformations of the Brain}
$Subject{Vascular Malformations of the Brain Intracranial Vascular
Malformations Occult Intracranial Vascular Malformations Cerebral
Malformations Arteriovenous Malformations Cavernous Malformations Venous
Malformations Telangiectasias Moyamoya Disease Cerebrovascular Accident
(Stroke) }
$Volume{}
$Log{}
Copyright (C) 1989 National Organization for Rare Disorders, Inc.
642:
Vascular Malformations of the Brain
** IMPORTANT **
It is possible that the main title of the article (Vascular Malformations
of the Brain) is not the name you expected. Please check the SYNONYM listing
to find the alternate names and disorder subdivisions covered by this
article.
Synonyms
Intracranial Vascular Malformations
Occult Intracranial Vascular Malformations
Cerebral Malformations
Disorder Subdivisions:
Arteriovenous Malformations
Cavernous Malformations
Venous Malformations
Telangiectasias
Information on the following diseases can be found in the Related
Disorders section of this report:
Moyamoya Disease
Cerebrovascular Accident (Stroke)
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.
Vascular Malformations of the Brain are conditions that affect the blood
vessels in the brain. They may be classified into four groups:
Arteriovenous Malformations (abnormal arteries and veins), Cavernous
Malformations (enlarged blood-filled spaces), Venous Malformations (abnormal
veins), and the Telangiectasias (enlarged capillary-sized vessels). Symptoms
and progression of these disorders vary with the type and severity of the
malformations.
Symptoms
Vascular Malformations of the Brain may cause headaches, seizures, strokes,
or bleeding in the brain (cerebral hemorrhage). Some researchers believe
that the type of malformation determines the symptoms and progression of the
disease. Other researchers believe that only the severity rather than the
type of malformation is important.
Arteriovenous Malformations or AVM's affect arteries, veins, and middle-
sized vessels but not capillaries. These blood vessels are enlarged and
twisted. Arteries and veins may be connected directly instead of being
connected through fine capillaries. (For more information on this disorder
choose "Arteriovenous" for your search term in the Rare Disease Database.)
Cavernous Malformations consist of abnormally enlarged collections of
blood-filled spaces. Cavernous Malformations may also be called Cavernous
Angiomas or Cavernous Hemangiomas.
Venous Malformations involve only the veins; they vary in size but do not
involve the arteries. The veins may be enlarged and twisted. These abnormal
veins may compensate for a lack of normal veins in another area of the brain.
Telangiectasias result from enlarged openings (dilation) of capillary-
sized vessels. Telangiectasias may occur on the face, eyes, membranes that
cover the brain and spinal cord (meninges), and mucous membranes (the thin
moist layer lining the body's internal surfaces).
Causes
The cause of Vascular Malformations of the Brain may be either congenital or
acquired. It may be inherited as an autosomal dominant trait with variable
expression and incomplete penetrance.
Human traits including the classic genetic diseases, are the product of
the interaction of two genes for that condition, one received from the father
and one from the mother. In dominant disorders, a single copy of the disease
gene (received from either the mother or father) will be expressed
"dominating" the normal gene and resulting in appearance of the disease. The
risk of transmitting the disorder from affected parent to offspring is 50%
for each pregnancy regardless of the sex of the resulting child. Incomplete
penetrance means that all characteristics of a particular trait may not be
manifested in all those who inherit the gene.
Malformations may also be the result of an injury or trauma. Symptoms
may appear because the injured blood vessels may have very small
malformations or lesions, a blood clot (thrombosis) may slow the blood flow,
or slight bleeding may effect nearby tissues in the brain.
Affected Population
Vascular Malformations of the Brain affect males and females in equal
numbers. A hereditary form of Cavernous Malformations tends to occur more
frequently in Mexican-Americans. Arteriovenous Malformations occur more
frequently in males.
Related Disorders
Symptoms of the following disorders can be similar to those of Vascular
Malformations of the Brain. Comparisons may be useful for a differential
diagnosis:
Cerebrovascular Accidents (Strokes) occur because the blood supply to the
brain has been cut off or decreased.
Thrombotic strokes occur when a clot has narrowed or completely closed an
artery in the neck or head. This is usually the result of the buildup of
fat-containing materials and calcium (plaque) on the inner linings of the
blood vessels (atherosclerosis or hardening of the arteries).
Embolic strokes occur when a clot breaks away from a diseased artery in
another part of the body or the heart and clogs a smaller artery in the
brain.
Hemorrhagic strokes occur when a blood vessel ruptures in or around the
brain, depriving that area of circulating blood.
Each type of stroke has its own symptoms, progression, and prognosis.
Clumsiness, headaches, speech difficulties, weakness or paralysis of one or
both sides of the body may occur. Stiff neck, nausea, vomiting, and loss of
consciousness are also common symptoms.
Moyamoya Disease is a progressive disease that effects blood vessels in
the brain (cerebrovascular). It is characterized by narrowing and/or closing
of the main artery to the brain (carotid) which decreases the blood supply.
This lack of blood may cause semi- or complete paralysis of the feet, legs or
the upper extremities. Cerebral bleeding, convulsions, headaches, various
vision problems, mental deficiencies, and psychiatric problems may also
occur. (For more information on this disorder, choose "Moyamoya" as your
search term in the Rare Disease Database.
Therapies: Standard
Imaging machines such as Digital Intravenous Computerized or Common
Angiography, Magnetic Resonance Imaging (MRI), Computed Tomography (CT)
Scans, and Venograms can take pictures of the brain's blood vessels to see if
Vascular Malformations are present.
Current treatment options vary according to the severity and location of
the malformation. Surgical Removal (Resection), Multiple Embolization (an
operation in which pellets are put into the circulatory system in order to
block the abnormal blood vessels), and Irradiation are the treatments
currently in use. In some cases treatment may not be necessary.
Genetic counseling may be of benefit for patients and their families if
they have a hereditary form of this disorder. Other treatment is symptomatic
and supportive.
Therapies: Investigational
Researchers are investigating several types of surgery that may be effective
in treating Vascular Malformations of the Brain. Charged-Particle
Radiosurgery, Interventriculostomy, and Catheter Placement are being studied.
Charged-Particle Radiosurgery involves a needlelike surgical instrument which
uses charged particles to cut tissue, to sterilize the edges of the wound,
and to seal cut blood vessels. Interventriculostomy involves creating an
opening in the brain to drain fluid. Catheters may be placed in the brain to
drain any excess fluid and to collapse the malformed vessels.
This disease entry is based upon medical information available through
April 1989. 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 Vascular Malformations of the Brain, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
NIH/National Institute of Neurological Disorders & Stroke (NINDS)
9000 Rockville Pike
Bethesda, MD 20892
(301) 496-5751
(800) 352-9424
For genetic information and genetic counseling referrals:
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10505
(914) 428-7100
Alliance of Genetic Support Groups
35 Wisconsin Circle, Suite 440
Chevy Chase, MD 20815
(800) 336-GENE
(301) 652-5553
References
VASCULAR MALFORMATIONS OF THE BRAIN: B.M. Stein & J.P Mohr; N Engl J Med
(August 11, 1988: issue 319(6)). Pp. 368-370.
CEREBRAL CAVERNOUS MALFORMATIONS: INCIDENCE AND FAMILIAL OCCURRENCE: D.
Rigamonti et al.; N Engl J Med (August 11, 1988: issue 319(6)). Pp. 343-
347.
CLINICAL, RADIOLOGICAL, AND PATHOLOGICAL SPECTRUM OF ANGIOGRAPHICALLY
OCCULT INTRACRANIAL VASCULAR MALFORMATIONS. ANALYSIS OF 21 CASES AND REVIEW
OF THE LITERATURE: R.D. Lobato et al.; J Neurosurg (April, 1988: issue
68(4)). Pp. 518-531.