There are three types of Spina bifida: spina bifida occulta, occult spinal dysraphism, and myelomeningocele.
Spina Bifida Occulta
Spina bifida occulta is a mild form in which the spinal cord is normal, but the spinal bones fail to form normally at one or more level. Between one in three and one in four people in the world, are born with this mild anomaly.
Occult Spinal Dysraphism
Occult spinal dysraphism (tethered cord syndrome) is a series of spinal and spinal cord abnormalities that comprise a continuum of severity. Though in all cases the skin of the spine is closed, a dimple, hairy patch, or reddish birthmark may be visible in the midline of the back. In the least severe forms, this syndrome can require a simple surgery that is curative. In the more severe forms, a child may need ongoing monitoring and intervention throughout their lives.
Adult patients with tethered cord syndrome may have skin abnormalities along the midline of their backs. They also can develop benign fatty collections or tumors (lipomyelomeningocele) in the spine, which can connect to the skin. Symptoms include back pain, leg weakness and/or change in bladder function.
In this most severe form of spina bifida where the spinal cord is visible outside of the body at birth. All children with myelomeningocele require urgent surgery after birth and 90 percent of patients will require treatment for hydrocephalus — usually an implanted shunt — at some time in their lives.