Conditions associated with spina bifida
The greatest concerns for babies born with spina bifida are hydrocephalus and loss of nerve function.
Hydrocephalus is often described as increased water of the brain. The “water” in and around the brain and spinal cord is called cerebrospinal fluid (CSF).
CSF is made on both sides of the brain. It then circulates around the entire brain and spinal cord, providing a cushion.
In the case of MMC, the CSF leaks out of the spine’s canal and into the amniotic fluid surrounding the baby. This leak reduces the cushion of CSF around the brain. The brain then lies on the bones of the head. The top of the spinal cord moves down and into the bones of the baby’s neck. The medical term for this is the Chiari 2 malformation.
When the brain settles against the bones of the baby’s head and the top of the spinal cord moves into the bones of the neck, the CSF cannot move well and collects in both sides of the brain (the lateral ventricles). This is hydrocephalus.
The treatment of hydrocephalus is referred to as shunting. The shunt is a piece of tubing (called a ventriculoperitoneal, or VP, shunt) placed in the baby’s brain, which allows the extra CSF to drain.
The placement of this shunt is done during an operation performed by a neurosurgeon. Seven of eight (85%) babies born with a myelomeningocele will need a VP shunt in their first year.
Spina bifida and nerve function
Loss of nerve function is another concern related to spina bifida.
With MMC, the nerves of the spinal cord, which do not have skin and bone covering them, may be damaged or lose function because they’re no longer protected by the spinal bones and their normal covering (the meninges).
The best-case scenario is that no nerve function loss is found at birth. The worst is that nerve function is completely lost. Most babies’ conditions will fall somewhere in between.
The loss of nerve function can affect the movement of legs (crawling and walking), bladder (being able to hold urine) and bowel (being able to hold a bowel movement). In general, the lower the MMC on the spine, the better a baby’s or child’s leg, bowel and bladder function. The higher the MMC on the spine, the worse the baby’s or child’s function of the legs, bowel and bladder.