[Spina bifida].

Spina bifida is a congenital disorder with incomplete closure of the spinal column due to a bony vertebral defect. The term spina bifida literally means cleft spine and is used as a generic term of spinal dysraphism (Greek: Raphe = seam). It is a midline defect that occurs during the embryonic period. The insufficient closure of one or more vertebral arches is the result of an incomplete junction of the neural tube. Depending on the extent of the neural tube defect, various types of spina bifida can be differentiated. Closed spinal dysraphisms, also known as spina bifida occulta, are solely characterized by a bony defect of the vertebral arch, whereas, spina bifida cystica (synonym: open spina bifida or spina bifida aperta) can be distinguished by a protruding cyst, containing either meninges or meninges in combination with spinal cord tissue and are defined as open spinal dysraphisms.