Spina bifida is the most common birth defect which is known as neural tube defect that affects the central nervous system (brain and spinal cord). Most commonly it occurs in the first month of pregnancy because of incomplete development of the spinal cord or its coverings.
The 3 variants of spin bifida have been identified and they are:
- Spina bifida occulta: It is the mildest and harmless form of spina bifida. The spinal cord and the nerves are normal but there may be a small defect or gap between the vertebra and does not cause any health problems.
- Meningocele: It occurs when the membranes of the spinal cord enlarge and protrude creating a cyst from the spinal opening. The defect is invisible through the skin and causes no problems.
- Myelomeningocele: This is the most severe form of spina bifida. It occurs when the spinal cord is exposed through the opening in the spine resulting in neurological problems. Children with this condition may have partial or complete paralysis of the parts of the body that are below the spinal opening. Most infants born with this condition also have hydrocephalus (accumulation of fluid in and around the brain), problems with bowel and bladder control, and other learning disabilities.
Children with spina bifida occulta exhibit no physical signs of the condition. In some cases, defects are recognized as a small dimple, birthmark, or a hairy patch at the site of the defect. In meningocele and myelomeningocele, fluid filled sac is visible on the spine. In most severe cases of myelomeningocele the nerves and the tissues from the spinal cord may get exposed.
Spina bifida affecting spinal cord may cause problems such as inability to control bowel movements, urinary incontinence, lack of sensation in the legs and feet, partial or complete paralysis of the legs, and less often, in the arms.
The exact cause for spina bifida remains unknown however certain factors may contribute to spina bifida and include genetic factors, environmental factors such as nutrition and radiation, and folic acid deficiency during early pregnancy.
Most cases of spina bifida can be diagnosed before birth with the help of prenatal tests such as alpha-fetoprotein (AFP) test, ultrasound, and amniocentesis. Postnatal tests include X- rays, CT scan of skull, and MRI and ultrasonography of the spinal area.
Treatment for spina bifida depends on clinical symptoms and most often includes physical therapy, antibiotics to prevent infection, and teaching the child bowel and bladder habits. Surgery is usually recommended after birth at an early age and they include spina bifida repair and ventriculoperitoneal shunting.