Spina Bifida is a developmental birth defect involving the neural tube: incomplete closure of the embryonic neural tube results in an incompletely formed spinal cord. In addition, the vertebrae overlying the open portion of the spinal cord do not fully form and remain unfused and open. This allows the abnormal portion of the spinal cord to stick out through the opening in the bones. The terms spina bifida and myelomeningocele are usually used interchangeably.
Spina Bifida and Hydrocephalus Association of Ontario