This article waslast modified on
July 10, 2017.
A birth defect in which the bones of the spine do not close around the spinal cord (the continuation of brain tissue that normally is surrounded by the spinal bones); this opening may be covered by skin (also called spina bifida occulta, which means hidden), in which case there may be no or mild symptoms. In other cases, the skin does not cover the defect, allowing the covering of the brain and spinal cord, the meninges, to protrude out through the skin (meningocele) or, in some cases, to rupture, exposing the spinal cord itself (meningomyelocyle). These latter two examples may cause severe damage to the nerves of the legs and lower abdomen, causing paralysis and bowel and bladder malfunction.