$Unique_ID{BRK03648} $Pretitle{} $Title{Dandy-Walker Syndrome} $Subject{Dandy-Walker Syndrome Dandy-Walker Cysts Dandy-Walker Deformity Internal Hydrocephalus Noncommunicating Hydrocephalus Obstructive Hydrocephalus Disorder Subdivision Dandy-Walker Malformation Arnold-Chiari Syndrome Hydrocephalus} $Volume{} $Log{} Copyright (C) 1986, 1989, 1991 National Organization for Rare Disorders, Inc. 275: Dandy-Walker Syndrome ** IMPORTANT ** It is possible the main title of the article (Dandy-Walker Syndrome) is not the name you expected. Please check the SYNONYMS listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Dandy-Walker Cysts Dandy-Walker Deformity Internal Hydrocephalus Noncommunicating Hydrocephalus Obstructive Hydrocephalus Disorder Subdivision Dandy-Walker Malformation Information on the following disease can be found in the Related Disorders section of this report: Arnold-Chiari Syndrome Hydrocephalus 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. Dandy-Walker Syndrome is a hereditary disorder characterized by developmental malformations caused by cysts on the fourth ventricle in the brain. Cerebrospinal fluid accumulates in this ventricle causing the head to become enlarged (hydrocephalus) due to excessive pressure. As a result, the brain cannot function properly. Symptoms In children born with Dandy-Walker Syndrome, the head is enlarged and the fourth ventricle in the brain contains an abnormally large amount of fluid. Headache, vomiting, double vision (diplopia) and blurred vision occur. Hyperirritability, weakness and congested veins in the scalp are other symptoms of this syndrome. The anterior soft spot in the skull tends to bulge. The cranial seams (sutures) are separated and the scalp tends to be shiny and thin. The eyes are displaced downward. The reflexes are often exaggerated and the foot makes abnormal rapid extension and relaxation movements induced by suddenly pushing up the foot (ankle clonus). Heart beat and breathing tend to be slow. Disorder Subdivision: Dandy-Walker Malformation is similar to Dandy-Walker Syndrome. However, it occurs as a central nervous system disorder that develops alone or in combination with other abnormalities. It may be genetic, congenital (present at birth), or develop for unknown reasons. Hydrocephalus develops in 85% of the patients. Causes Dandy-Walker Syndrome is an autosomal recessive hereditary disorder. A congenital obstruction in the windows from the fourth ventricle in the brain prevents the entrance of cerebrospinal fluid into the subarachnoid space above the fourth ventricle in the brain. 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 recessive disorders, the condition does not appear unless a person inherits the same defective gene 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. Affected Population Dandy-Walker Syndrome is very rare. According to one report of ten children with the syndrome treated surgically in Philadelphia, seven were male and three were female. Related Disorders Arnold-Chiari syndrome is a defect in the formation of several brainstem areas. The cerebellar tonsils are elongated and protrude through the hole in the skull at the entrance of the spinal cord, the rounded elevations of the middle brain tend to beak, and the upper neck (cervical) portion of the spinal cord is thick. Excessive fluid in the brain (hydrocephalus) may result from blockage of the fourth ventricle as in Dandy-Walker Syndrome. (For more information on this disorder, choose "Arnold-Chiari" as your search term in the Rare Disease Database.) Hydrocephalus is a symptom that can be caused by a variety of neurological disorders. Treatment of this symptom is surgical implantation of a shunt which drains excess fluid from the brain. (For more information on this disorder, choose "hydrocephalus" as your search term in the Rare Disease Database.) Therapies: Standard Treatment for Dandy-Walker Syndrome consists of surgically performing combined shunt procedures to the posterior ridge cyst and the lateral ventricles, draining fluid from the inside of brain. In many cases this procedure prolongs the life of children with Dandy-Walker Syndrome. Special education services are useful to children who have mental retardation. Therapies: Investigational This disease entry is based upon medical information available through August 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 Dandy-Walker Syndrome, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 Hydrocephalus Parent Support Group 225 Dickinson St., H-893 San Diego, CA 92103 (619) 695-3139, or (619) 726-0507 National Hydrocephalus Foundation 400 N. Michigan Ave., Suite 1102 Chicago, IL 60611-4102 Hydrocephalus Association 870 Market St., Suite 955 San Francisco, CA 94102 (415) 776-4713 NIH/National Institute of Neurological Disorders & Stroke (NINDS) 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5751 (800) 352-9424 For information on genetics 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 Problems of Diagnosis and Treatment in the Dandy-Walker Syndrome: HE James et al.; in: Child's Brain 5: 24-30 (1979).