论文部分内容阅读
1背景神经管缺陷(NTDs)是在脑和脊索发育过程中形成的先天性畸形,包括无脑儿(颅骨、表面皮肤和脑组织全部或部分缺失)、脊柱裂(脊柱未闭合造成的脊索、脊膜分别或同时突出或暴露;有些病例合并脑积水)和脑膨出(脑膜疝,脑组织位于颅骨外,表面被正常或萎缩皮肤覆盖)。胚胎发育时背侧表层的一群细胞发育成凹槽,进而发展为中空的管道。这一过程完成于受孕后1个月内(约为末次月经后第6周),神经管闭合不全导致NTDs。无脑儿无法生存,而另两种NTDs(脊柱裂和脑膨出)的围产儿和婴儿的死亡率则很高。存活儿童的受损(失禁,运动和感觉能力降低,学习困难)程度从轻度到极严重不等,通常都很严重,严重程度取决于缺陷的部位、大小、神经组织破坏程度和伴随的脑积水(脑室内液体量异常增多)程度。
1 BACKGROUND Neural tube defects (NTDs) are congenital anomalies that develop during the development of the brain and chordae. They include the absence of the brain (skull, surface skin and brain tissue in whole or in part), spina bifida (chordate, Meningiomas either singly or in combination or at the same time; in some cases with hydrocephalus) and encephalocele (meningeal hernia, where the brain tissue is located outside the skull and the surface is covered by normal or atrophic skin). A group of cells in the dorsal surface develop into grooves during embryonic development and develop into hollow tubes. This process is completed within 1 month after conception (about the last 6 weeks after menstruation), neural tube insufficiency led to NTDs. No brain can not survive, while the other two NTDs (spina bifida and encephalocele) perinatal and infant mortality is very high. The levels of survivors’ damage (incontinence, decreased motor and sensory ability, learning difficulties) range from mild to very severe and often severe, depending on the location of the defect, size, extent of nerve tissue destruction, and accompanying brain Hydrocephalus (an abnormal increase in the volume of intraventricular fluid) level.