|Other encyclopedia topics:||A-Ag Ah-Ap Aq-Az B-Bk Bl-Bz C-Cg Ch-Co Cp-Cz D-Di Dj-Dz E-Ep Eq-Ez F G H-Hf Hg-Hz I-In Io-Iz J K L-Ln Lo-Lz M-Mf Mg-Mz N O P-Pl Pm-Pz Q R S-Sh Si-Sp Sq-Sz T-Tn To-Tz U V W X Y Z 0-9|
|Contents of this page:|
Alternative Names Return to topSpina bifida; Cleft spine
Definition Return to top
Myelomeningocele is a birth defect in which the backbone and spinal canal do not close before birth. The condition is a type of spina bifida.
Causes Return to top
Myelomeningocele is one of the most common birth defects of the central nervous system. It is a neural tube defect in which the bones of the spine do not completely form, resulting in an incomplete spinal canal. This causes the spinal cord and meninges (the tissues covering the spinal cord) to stick out of the child's back.
Myelomeningocele accounts for about 75% of all cases of spina bifida and may affect as many as 1 out of every 800 infants. Spina bifida includes any birth defect involving insufficient closure of the spine.
The rest of myelomeningocele cases are most commonly:
Other congenital disorders may also be present in the child. Hydrocephalus may affect as many as 90% of children with myelomeningocele. Other disorders of the spinal cord or musculoskeletal system may be seen, including syringomyelia and hip dislocation.
The cause of myelomeningocele is unknown. However, folic acid deficiency is thought to play a part in neural tube defects. Also, if a child is born with myelomeningocele, subsequent children in that family have a higher risk than the general population.
Some theorize that a virus make play a role, since there is a higher rate of this condition in children born in the early winter months. Research also indicates possible environmental factors such as radiation.
Symptoms Return to top
A newborn may have a sac sticking out of the mid to lower back. The doctor cannot see through the sac when shining a light behind it. Symptoms include:
The exposed spinal cord is susceptible to infection. Other symptoms may include:
Exams and Tests Return to top
Prenatal screening can help diagnose this condition. During the second trimester, pregnant women can have a blood test called the quadruple screen. This test screens for myelomeningocele, Down syndrome, and other congenital diseases in the baby. Most women carrying a baby with spina bifida will have a higher-than-normal levels of a protein called maternal alpha fetoprotein (AFP).
If the quadruple screen test is positive, further testing is needed to confirm the diagnosis. Such tests may include:
Myelomeningocele can be seen after the child is born. A neurologic examination may show that the child has loss of nerve-related functions below the defect. For example, watching how the infant responds to pinpricks at various locations may reveal where he or she can feel the sensations.
Tests done on the baby after birth may include x-rays, ultrasound, CT, or MRI of the spinal area.
Treatment Return to top
Genetic counseling may be recommended. In some cases where severe defect is detected early in the pregnancy, a therapeutic abortion may be considered.
After birth, surgery to repair the defect is usually recommended at an early age. Before surgery, the infant must be handled carefully to reduce damage to the exposed spinal cord. This may include special care and positioning, protective devices, and changes in the methods of handling, feeding, and bathing.
Antibiotics may be used to treat or prevent infections such as meningitis or urinary tract infections.
Gentle downward pressure over the bladder may help drain the bladder. In severe cases, drainage tubes, called catheters, may be needed. Bowel training programs and a high fiber diet may improve bowel function.
Orthopedic or physical therapy may be needed to treat musculoskeletal symptoms. Neurological losses are treated according to the type and severity of function loss.
Follow-up neurologic testing as the child gets older helps to guide rehabilitation.
Support Groups Return to top
See: Spina bifida resources
Outlook (Prognosis) Return to top
A myelomeningocele can usually be surgically corrected. With treatment, length of life is not severely affected. Neurological damage is often irreversible.
Possible Complications Return to top
This list may not be all inclusive.
When to Contact a Medical Professional Return to top
Call your health care provider if:
Prevention Return to top
Folic acid supplements may help reduce the risk of neural tube defects such as myelomeningocele. It is recommended that any woman considering becoming pregnant take 0.4 mg of folic acid a day. Pregnant women need 1 mg per day.
It is important to remember that folic acid deficiencies must be corrected before becoming pregnant as the defects develop very early.
Prospective mothers may be screened to determine the amount of folic acid in their blood.Update Date: 12/12/2008 Updated by: A.D.A.M. Editorial Team: David Zieve, MD, MHA, Greg Juhn, MTPW, David R. Eltz. Previously reviewed by Deirdre O’Reilly, MD, MPH, Neonatologist, Division of Newborn Medicine, Children’s Hospital Boston and Instructor in Pediatrics, Harvard Medical School, Boston, Massachusetts. Review Provided by VeriMed Healthcare Network (10/11/2007).