الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
The term neural tube defect (NTD) or what is called spinal dysraphism is used to refer to the incomplete fusion or malformation of bone and neural structures of the spine region by e The development and closure of the neural tube are normally completed within 28 days after conception, before many women are aware that they are pregnant. It is generally accepted that neural-tube defects are caused by the failure of the neural tube to close, although it has also been suggested that a closed tube may reopen in some cases rrors in the closure of the neural tube during the fourth week of embryogenesis The majority of NTDs result in either anencephaly or meningomyelocele, with each defect seen in almost equal proportions at birth. Anencephaly is a lethal defect, characterized by acrania and rudimentary or absent cerebral hemispheres and cerebellum (Brender et al., 1989). Meningomyelocele, also called spina bifida or spina bifida cystica, is compatible with life but results in handicap approximately 99% of the time. In meningomyelocele, protrusion of the spinal cord and meninges through a defect in the vertebral arch can occur anywhere along the spinal column but is most common in the lumbar region