A to Z: Myelomeningocele

May also be called: Meningomyelocele; Spina Bifida; Open Spinal Dysraphism

Myelomeningocele (my-uh-low-meh-NIN-guh-seel) is a type of spina bifida. Spina bifida is a birth defect that happens when the spinal cord and the membranes that cover and protect the brain and spinal cord (meninges) push through an abnormal hole in the back and form a fluid-filled sac.

More to Know

Spina bifida, which happens at the end of the first month of pregnancy, is a birth defect that occurs when the spinal cord or its coverings don't develop completely.

In spina bifida, the two sides of an embryo's spine fail to join together, leaving an open area in the back. In some cases, the spinal cord or other membranes push through this opening. If just the meninges push through, the condition is called meningocele. Myelomeningocele happens when both the meninges and the spinal cord push through.

Myelomeningocele is the most severe form of spina bifida. Because of the abnormal development of and damage to the spinal cord, a child with myelomeningocele usually has some paralysis. The degree of paralysis depends on where the opening is in the spine. The higher the opening is on the back, the more severe the paralysis tends to be. Most babies born with myelomeningocele also have hydrocephalus, a buildup of fluid in and around the brain.

Myelomeningocele is usually detected in prenatal screening tests before a baby is born and treated with surgery after birth. During the surgery, doctors push the spine back into the vertebrae (the small, ring-like bones that make up the spinal column) and close the hole to prevent infection and protect the spine.

Keep in Mind

With the right treatment and ongoing care, most kids born with myelomeningocele can expect to lead a productive life and have a relatively normal life span. However, some amount of paralysis or weakness in the legs usually can be expected due to nerve damage. As a result, many kids with myelomeningocele will use wheelchairs to get around.

All A to Z dictionary entries are regularly reviewed by KidsHealth medical experts.