Defining Spina Bifida
Spina bifida is a neural tube defect that occurs early in pregnancy, often before a woman even realizes she is pregnant. At some point during this time in the embryo's development, the neural tube (which develops into the brain, spinal cord, and vertebral column) fails to form properly, leaving the spinal cord exposed. The result is varying degrees of paralysis and loss of sensation.
The severity of spina bifida is dependent upon two factors. The first is where along the spine the defect is located. The second is whether the child experiences symptoms of paralysis and loss of sensation above or below the affected area.
To understand both factors, it's helpful to know that the spine is divided into three sections. The top is the cervical (neck) area, which is comprised of the upper seven vertebrae in the spine. Lesions in this area often do not cause paralysis. Below that are the 12 vertebrae that comprise the thoracic region (around the ribs). After that are the five lumbar vertebrae of the lower back. Last are the fused vertebrae of the sacrum and coccyx. Generally, the higher the lesion, the more severe the symptoms, so a child with L-3 spina bifida has a lesion on the third lumbar vertebrae. A child with T-5 has a lesion on the fifth thoracic vertebrae and, thus, a more severe case. Sometimes multiple vertebrae are affected.
As for functionality, that depends upon the highest level where paralysis and/or lack of sensation occur. For example, a child may have an L-5 lesion, but function as an L-1 because that's where the paralysis begins. In other words, it's not an exact science, and there's no way to conclusively categorize any child until they are old enough to have measurable motor skills.
Other issues with spina bifida can be even more challenging to deal with. Usually, even in the mildest cases of spina bifida, there is loss of bowel and bladder control. As a result, the bladder is emptied through catheterization. Until a child learns to do the procedure, he or she has to rely on others.
In addition, most children with spina bifida also develop hydrocephalus, which results when cerebral spinal fluid builds up inside the head and causes pressure in the brain. These children are operated on shortly after birth to have a shunt placed in their brain to help drain the fluid, but this doesn't correct damage that has already been done. Thus, children with spina bifida can be prone to learning disabilities and, as they get older, have difficulty with organization and time management issues.