Spina bifida is a neural tube birth defect (NTD) which occurs within the first four weeks of pregnancy. The spinal column fails to develop properly resulting in varying degrees of permanent damage to the spinal cord and nervous system.
Infants born with spina bifida may have an open lesion on their spine where significant damage to the nerves and spinal cord occurs. Although the spinal opening is surgically repaired shortly after birth, the nerve damage is permanent. This results in varying degrees of paralysis of the lower limbs, depending largely on the location and severity of the lesion. Even with no visible lesion, there may be improperly formed or missing vertebrae, and accompanying nerve damage.
This video has been produced by The Children's Hospital of Philadelphia www.chop.edu
The three most common types of spina bifida are:
- Spina bifida occulta - a mild form of spina bifida in which the spinal cord and the surrounding structures remain inside the body, but the back bones in the lower back area fail to form normally. There may be a hairy patch, dimple, or birthmark over the area of the defect. Other times, there may be no abnormalities in the area.
- Meningocele - a moderate form of spina bifida in which a fluid-filled sac is visible outside of the back area. The sac does not contain the spinal cord or nerves.
- Myelomeningocele - a severe form of spina bifida in which the spinal cord and nerves develop outside of the body and are contained in a fluid-filled sac that is visible outside of the back area. These babies typically have weakness and loss of sensation below the defect. Problems with bowel and bladder function are also common. A majority of babies with myelomeningocele will also have hydrocephalus, a condition that causes the fluid inside of the head to build up, causing pressure inside of the head to increase and the skull bones to expand to a larger than normal size.