The neural tube is embryonic tissue from which the brain and spinal cord develop. Failure to close can result in serious birth defects including spina bifida. There are three main types of spina bifida: spina bifida occulta, meningocele and myelomeningocele.
Spina bifida occulta is the most common form and the mildest. One or more vertebrae are malformed and are usually covered by a layer of skin. This form of spina bifida rarely causes disability.
Meningocele is where the spinal cord develops normally but the meninges (the protective covering around the brain and spinal cord) protrude from a spinal opening. The protuberances may or may not have a layer of skin covering them. In some cases there may be few or no symptoms with this type of spina bifida, while in others it causes various degrees of paralysis; sometimes with bowel and urinary dysfunction.
Myelomeningocele is the most severe form of spina bifida and can be very serious or even fatal. It occurs when a section of the spinal cord and nerves are exposed through an opening in the spine, or there is a cyst that holds the nerves and often the spinal cord. This usually results in some form of paralysis and runs a high risk of infection if not closed surgically at birth. There are varying degrees of paralysis, some so severe that affected individuals are unable to walk and may have bowel and urinary dysfunctions. Generally, the higher on the back the cyst is, the more severe the paralysis.
For more information on this disorder, visit:
- NINDS – What is Spina Bifida? – National Institute of Neurological Disorders and Stroke
- March of Dimes Foundation – Spina Bifida
- eMedicine Health – Spina Bifida
- What is Spina Bifida? – BBC Health