Myelomeningocele

Myelomeningocele is the most severe form of spina bifida. It happens when parts of the spinal cord and nerves come through the open part of the spine. It causes nerve damage and other disabilities. Seventy to ninety percent of children with this condition also have too much fluid on their brains (hydrocephalus). This happens because fluid that protects the brain and spinal cord is unable to drain like it should. The fluid builds up, causing pressure and swelling. Without treatment, a person’s head grows too big, and they may have brain damage.^[1] Other disorders of the spinal cord may be seen, including syringomyelia and hip dislocation. The cause of myelomeningocele is unknown. However, low levels of folic acid in a woman's body before and during early pregnancy is thought to play a part in this type of birth defect.^[2]

A baby born with a myelomeningocele may have a sac sticking out of the mid to lower back that the doctor cannot see through when shining a light behind it. Symptoms of this condition include:^[2][3]

• Loss of bladder or bowel control
• Partial or complete lack of sensation
• Partial or complete paralysis of the legs
• Weakness of the hips, legs, or feet

Some individuals may have additional symptoms. Other symptoms include:

• Abnormal feet or legs, such as clubfoot.
• Build up of fluid inside the skull (hydrocephalus)
• Hair at the back part of the pelvis called the sacral area
• Dimpling of the sacral area
• Meningitis
• Chiari II malformation

Twenty to 50 percent of children with myelomeningocele develop a condition called progressive tethering, or tethered cord syndrome. A part of the spinal cord becomes fastened to an immovable structure—such as overlying membranes and vertebrae—causing the spinal cord to become abnormally stretched and the vertebrae elongated with growth and movement. This condition can cause change in the muscle function of the legs, as well as changes in bowel and bladder function. Early surgery on the spinal cord may help the child to regain a normal level of functioning and prevent further neurological deterioration.^[3]

A child with meningomyelocele usually has surgery to close the myelomenigocele shortly after birth. This prevents infections and helps save the spinal cord from more damage.^[1] Children who also have hydrocephalus may need a ventricular peritoneal shunt placed. This will help drain the extra fluid.^[2] In the United States, antibiotics, sac closure, and ventriculoperitoneal shunt placement are the standard of care and are implemented soon after birth in 93-95% of patients.^[4]

Children with myelomeningocele should be scheduled for regular follow-up visits in the multidisciplinary clinic every 6 months throughout childhood and annually thereafter. These follow up visits are done to check the child’s developmental level and to treat any intellectual, neurological or physical problems. ^[4] Most children will require lifelong treatment for problems that result from damage to the spinal cord and spinal nerves. This includes:^[2]

• 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. Braces may be needed for muscle and joint problems.
• Neurological losses are treated according to the type and severity of function loss.