Introduction
The usual incidence of meningomyelocele, or spina bifida, is about one in every 1,000 live births. Although there is no definitive etiology, it seems clear that the pathological process begins before the fourth week of gestation. Neurulation (the normal closing process of the fetus's brain and spinal cord) is normally complete by that time, but it is uncertain whether this disorder represents a failure of neurulation in the base of the spinal cord, or a rupture there after neurulation has become complete. Whatever the cause, there is a defect in the spinal cord's base, with protrusion of the spinal cord and its coverings through a defect in the skin. The condition is often associated with disruption of the cerebrospinal fluid pathways with a resulting hydrocephalus.
The degree of neurological deficit is directly related to the level of the spinal cord defect and its extent. If only the bottom of the spinal cord is involved (conus), there may be only bowel and bladder dysfunction, while the most extensive lesions can result in total paralysis of the legs with accompanying bowel and bladder dysfunction. It is because of the varying neurological manifestations of meningomyelocele that there has been so much controversy regarding appropriate treatment.