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$Unique_ID{BRK04011}
$Pretitle{}
$Title{Moyamoya Disease}
$Subject{Moyamoya Disease Moya Moya Disease Moya-moya Disease Moyamoya
Syndrome Cerebrovascular Moyamoya Disease Cerebrovascular Accident (CVA) or
(Stroke) Cerebral Vascular Malformations }
$Volume{}
$Log{}
Copyright (C) 1989 National Organization for Rare Disorders, Inc.
617:
Moyamoya Disease
** IMPORTANT **
It is possible that the main title of the article (Moyamoya Disease) is
not the name you expected. Please check the SYNONYM listing to find the
alternate names and disorder subdivisions covered by this article.
Synonyms
Moya Moya Disease
Moya-moya Disease
Moyamoya Syndrome
Cerebrovascular Moyamoya Disease
Information on the following diseases can be found in the Related
Disorders section of this report:
Cerebrovascular Accident (CVA) or (Stroke)
Cerebral Vascular Malformations
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.
Moyamoya disease is a progressive disease that effects the blood vessels
in the brain (cerebrovascular). It is characterized by narrowing and/or
closing of the main artery to the brain (carotid). This lack of blood may
cause paralysis of the feet, legs or the upper extremities. Headaches,
various vision problems, mental retardation, and psychiatric problems may
also occur.
Symptoms
Moyamoya disease may occur at any age. The age of onset tends to determine
the various symptoms. Cerebral bleeding (hemorrhage) and anemia, headaches,
speech disorders, and sudden onsets of recurrent paralysis usually occur in
juvenile Moyamoya patients. Children afflicted with Moyamoya disease may
have convulsions or involuntary movements. Some may show signs of mental
retardation. Patients tend to develop one or more of the following visual
disturbances: blindness in one half of the visual field of one or both eyes
(hemianopia), double vision (diplopia), bilaterally (right and left)
decreased visual clearness (acuity), and the inability to recognize objects.
Fainting, intracranial hemorrhage below the middle covering of the brain
(subarachnoid) followed by accumulation of excessive amounts of watery fluid
in the optic disks (papilledema) may also occur. Neurosis (mainly anxiety)
usually occurs in adult Moyamoya patients. Patients usually have sudden
insufficiencies of blood supplies in the brain (cerebral infarctions) which
can lead to brain tissue death.
Causes
The exact cause of Moyamoya disease is not known. It is thought to be
inherited as an autosomal recessive trait in a small number of cases. (Human
traits including the classic genetic diseases, are the product of the
interaction of two genes, one received from the father and one from the
mother. In recessive disorders, the condition does not appear unless a
person inherits the same defective gene for the same trait from each parent.
If one receives one normal gene and one gene for the disease, the person will
be a carrier for the disease, but usually will show no symptoms. The risk of
transmitting the disease to the children of a couple, both of whom are
carriers for a recessive disorder, is twenty-five percent. Fifty percent of
their children will be carriers, but healthy as described above. Twenty-five
percent of their children will receive both normal genes, one from each
parent, and will be genetically normal.)
Studies suggest oral contraceptive use may possibly contribute to a small
number of Moyamoya cases in women, although this has not been definitely
confirmed. Pregnancy may also contribute to the development of Moyamoya.
Affected Population
Moyamoya disease occurs mainly in females under the age of 20, particularly
of Japanese origin. In one Japanese study, 7% of the cases were familial.
Familial cases, including identical twins, have also been reported in Europe.
Related Disorders
Symptoms of the following disorders can be similar to those of Moyamoya
disease. Comparisons may be useful for a differential diagnosis:
A Cerebrovascular Accident (stroke) occurs 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 the result of the buildup of fat-containing materials and calcium (plaque)
on the inner linings of the blood vessels. Embolic strokes occur when a clot
breaks away from the diseased artery in another part of the body 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 blood. Each type of
stroke has its own symptoms, progression, and prognosis. Clumsiness,
headaches, speech difficulties, weakness or complete paralysis of one or both
sides of the body may occur. Stiff neck, nausea, vomiting, and
unconsciousness are also common symptoms.
Vascular malformations (abnormal blood vessels) of the brain are
classified into arteriovenous malformations (abnormal arteries and veins),
cavernous malformations (enlarged channels of blood vessels), venous
malformations (abnormal veins), and the telangiectasias (enlarged capillary-
sized vessels). Malformations in the brain may cause recurrent headaches,
seizures, and hemorrhaging. Hemorrhaging in the brain may cause
cerebrovascular accidents (strokes).
Therapies: Standard
Angiograms and Magnetic Resonance Imaging (MRI) are diagnostic tests that can
show the brain's blood vessels to see if they are indicative of Moyamoya
disease. Effective treatment of Moyamoya has been unsuccessful in the past;
however, surgical treatment and drug therapy research is encouraging. There
are five surgical treatments currently in use: Encephalomyosynangiosis
(EMS), Encephaloduroarteriosynangiosis (EDAS), Encephalomyoarteriosynangiosis
(EMAS), Superficial Temporal-to-Middle Cerebral Artery (STA-MA) Bypass, and
Indirect Non-Bypass Revascularization. Response of patients to these complex
and very complicated surgeries varies.
Drug therapy now in use is intravenous administration of verapamil, a
calcium-channel blocker which dilates certain blood vessels.
The disease may also stabilize after a progressive course.
Genetic counseling may be of benefit for patients and their families if
they have the hereditary form of Moyamoya Disease. Other treatment is
symptomatic and supportive.
Therapies: Investigational
Researchers are investigating two types of drugs that may be effective in
treating Moyamoya disease: calcium-channel blockers and anti-aggregating
(anti-blood clotting) drugs.
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 Moyamoya Disease, please contact:
National Organization for Rare Disorders (NORD)
P.O. Box 8923
New Fairfield, CT 06812-1783
(203) 746-6518
Families with Moyamoya Network
14197 E. Kansas Pl., #105
Aurora, CO 80012
or
1282 Skylark Dr., RR #3
Cedar Rapids, IA 52403
(319) 362-8315
NIH/National Institute of Neurological Disorders & Stroke (NINDS)
9000 Rockville Pike
Bethesda, MD 20892
(301) 496-5751
(800) 352-9424
Children's Brain Diseases Foundation for Research
350 Parnassus, Suite 900
San Francisco, CA 94117
(415) 566-5402
(415) 565-6259
For genetic information and genetic counseling referrals, please contact:
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
(914) 428-7100
Alliance of Genetic Support Groups
35 Wisconsin Circle, Suite 440
Chevy Chase, MD 20815
(800) 336-GENE
(301) 652-5553
References
MENDELIAN INHERITANCE IN MAN, 7th ed.: Victor A. McKusick; Johns Hopkins
University Press, 1986. Pp. 1068.
INTERNAL MEDICINE, 2nd Ed.: Jay H. Stein, ed.-in-chief; Little, Brown and
Co., 1987. Pp. 2213-2214.
CEREBRAL INFARCTION DUE TO MOYAMOYA DISEASE IN YOUNG ADULTS: A. Bruno,
et al.; Stroke (July, 1988: issue 19(7)). Pp. 826-833.
OCULAR SYMPTOMS OF MOYAMOYA DISEASE: S. Noda, et al.; Am J Ophthalmol
(June 15,1987: issue 103(6)). Pp. 812-816.
PITFALLS IN THE SURGICAL TREATMENT OF MOYAMOYA DISEASE. OPERATIVE
TECHNIQUES FOR REFRACTORY CASES: S. Miyamoto et al.; J Neurosurg (April,
1988: issue 68(4)). Pp. 537-543.
TREATMENT OF ACUTE DEFICITS OF MOYAMOYA DISEASE WITH VERAPAMIL: M.J.
McLean et al.; Ann Acad Med Singapore (January, 1985: issue 14(1)). Pp. 65-
70.