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Dandy–Walker syndrome (DWS), is a congenital human brain malformation involving the cerebellum and the fluid-filled spaces around it. A key feature of this syndrome is the complete absence of the part of the brain located between the two cerebellar hemispheres (cerebellar vermis).〔National Institute of Neurological Disorders and Stroke, "NINDS Dandy–Walker Syndrome Information Page," http://www.ninds.nih.gov/disorders/dandywalker/dandywalker.htm. Last updated September 16, 2008. Last accessed July 6, 2009.〕 The Dandy–Walker complex is a genetically sporadic disorder that occurs one in every 30,000 live births. Prenatal diagnosis and prognosis of outcomes associated with Dandy–Walker can be difficult. It is named for Walter Dandy and Arthur Earl Walker.〔http://www.whonamedit.com/doctor.cfm/418.html〕 ==Presentation== The key features of this syndrome are an enlargement of the fourth ventricle; complete absence of the cerebellar vermis, the posterior midline area of cerebellar cortex responsible for coordination of the axial musculature; and cyst formation near the internal base of the skull. An increase in the size of the fluid spaces surrounding the brain as well as an increase in pressure may also be present. The syndrome can appear dramatically or develop unnoticed. Symptoms, which often occur in early infancy, include slower motor development and progressive enlargement of the skull. In older children, symptoms of increased intracranial pressure such as irritability, vomiting, and convulsions and signs of cerebellar dysfunction such as unsteadiness and lack of muscle coordination or jerky movements of the eyes may occur. Other symptoms include increased head circumference, bulging at the back of the skull, problems with the nerves that control the eyes, face and neck, and abnormal breathing patterns. Dandy–Walker syndrome is frequently associated with disorders of other areas of the central nervous system including absence of the corpus callosum, the bundle of axons connecting the two cerebral hemispheres, and malformations of the heart, face, limbs, fingers and toes.〔 Prenatal diagnosis is possible with ultrasound. Because the syndrome is associated with an increased risk for fetal karyotype abnormalities, amniocentesis can be offered after prenatal diagnosis.〔Romero R, Pilu G, Jeanty P, Ghidini A, Hobbins JL. Prenatal diagnosis of congenital anomalies. Appleton & Lange, Norwalk, 1988, pp. 30-33.〕 There is a relative contraindication of taking Warfarin during pregnancy, as it is associated with an increased risk of Dandy–Walker syndrome if taken during the first trimester. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Dandy–Walker syndrome」の詳細全文を読む スポンサード リンク
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