Spina bifida

Spina bifida (SB; ; Latin for 'split spine') is a birth defect in which there is incomplete closing of the spine and the membranes around the spinal cord during early development in pregnancy. There are three main types: spina bifida occulta, meningocele and myelomeningocele. Meningocele and myelomeningocele may be collectively referred to as spina bifida cystica (also called spina bifida aperta) due to the protrusion of the spinal cord and/or meninges through defects in the vertebral arches, resulting in a meningeal cyst. The most common location is the lower back, but in rare cases it may be in the middle back or neck.

Occulta has no or only mild signs, which may include a hairy patch, dimple, dark spot or swelling on the back at the site of the gap in the spine, while cystica shows clear external meningeal cyst from the protrusion of the meninges and cerebrospinal fluid. Meningocele typically causes mild problems, with a sac of fluid present at the gap in the spine. Myeloschisis, also known as open spina bifida, is the most severe form. This occurs when the spinal cord in the affected area is exposed to the environment due to failure of neural folds and overlying skin to fuse. Problems associated with this form include poor ability to walk, impaired bladder or bowel control, accumulation of fluid in the brain, a tethered spinal cord and latex allergy, and usually results in permanent paralysis or weakness of the lower limbs. Some experts believe such an allergy can be caused by frequent exposure to latex, which is common for people with spina bifida who have shunts and have had many surgeries.