Spina Bifida is a birth defect that occurs during fetal development when the spine does not form normally. As a result, the spinal cord, vertebrae, nerves and surrounding tissues may also be affected. The term spina bifida means “split spine” and it falls under the category of neural tube defects. The neural tube is an embryonic structure that will develop into a baby’s brain, spinal cord, and the tissues that enclose them.
Causes and Risk Factors
Normally, the neural tube forms early in pregnancy and closes by the end of the first month of pregnancy. This is when the spina bifida defect usually occurs. The cause of spina bifida is unclear, but it may be linked to a combination of genetic and environmental risk factors, such as:
- A family history of neural tube defects.
- A folate (vitamin B-9) deficiency
- Diabetes and/or obesity
Spina bifida can occur in different forms. The severity of symptoms can range from mild to severe, depending on the type, size, location, and complications.
Spina Bifida Occulta – “Occulta” means “hidden” in Latin, and this type of spina bifida is often called “hidden spina bifida.” The mildest form, spina bifida occulta results in a small separation or gap in one or more of the bones of the spine (vertebrae). Many people do not even know they have spina bifida occulta, though some may have pain or other neurological symptoms. A tethered cord, where the spinal cord is attached to surrounding tissue instead of floating freely, is a common complication of spina bifida occulta that may require surgery.
Meningocele – In meningocele, the protective membranes that surround the spinal cord (meninges) push through openings in the vertebrae, forming a sac filled with nerve fluid (meningocele). The sac may be visible on a child’s head, neck, or back, and can happen anywhere along the spinal column or at the base of the skull. Because meningocele does not typically include the spinal cord, nerve damage is less likely. However, children with meningocele may have health complications if the nerves surrounding the spine are damaged. The severity of symptoms depends on the size of the meningocele and where it is located on the spinal column.
Myelomeningocele or Spina Bifida Cystica – Known as open spina bifida, myelomeningocele is the most common and most severe form of spina bifida. It occurs when some of the bones in the back do not develop properly and do not close completely around the spinal cord. As a result, portions of the spinal cord, nerves, and surrounding tissue push through the incomplete backbone and are exposed. This often forms a sac that sticks out on a child’s back, typically exposing tissues and nerves. This can cause proneness to infection. Children also typically will lose nerve function below the location in which the defect occurs, leading to sensation loss, paralysis, and bladder problems. The paralysis can lead to deformities of the legs, feet, and back such as scoliosis. Children with myelomeningocele often have a buildup of cerebrospinal fluid in and around their brain because the fluid that protects the brain and spinal cord is unable to drain properly.
Treatment for spina bifida depends on the severity of the deformity. Children with spina bifida occulta may not need any treatment, while children with myelomeningocele typically require surgery 1-2 days after birth to protect the exposed areas. Because spina bifida can involve many different body systems, your child may need support from a team of medical professionals.