Forms of Spina Bifida

In occult spinal dysraphism, ≥ 1 vertebrae do not form normally, and the spinal cord and meninges may also be affected.

In spina bifida cystica, the protruding sac can contain meninges (meningocele), spinal cord (myelocele), or both (myelomeningocele). In a myelomeningocele, the meninges are usually exposed or, rarely, are covered by a thin layer of skin (as shown in the figure).