Myelomeningocele: Symptoms, Causes & Treatment

Myelomeningocele is the most severe type of spina bifida, in which the bones of the spine do not fully close during pregnancy. As a result, a sac forms on the baby’s back that contains the spinal cord, nerves, and cerebrospinal fluid.

This sac usually appears in the lower back, but it can develop anywhere along the spine. It can cause symptoms such as loss of sensation, movement problems, and urinary and fecal incontinence.

Treatment for myelomeningocele involves surgery to close the sac and protect the spinal cord. However, surgery cannot completely reverse damage that has already happened.

Main symptoms

The main symptoms of myelomeningocele are:

• A sac on the baby’s back

• Muscle weakness

• Loss of sensation below the lesion

• Difficulty moving the legs and feet, which may range from weakness to paralysis

• Urinary and fecal incontinence

• Developmental delays

• Learning difficulties

• Seizures

In some cases, excess cerebrospinal fluid (CSF) may build up in the brain, a condition known as hydrocephalus.

Musculoskeletal problems may also occur, including clubfoot, hip dislocation, and abnormal curvature of the spine (such as scoliosis), as well as complications affecting the heart and kidneys.

Symptom severity varies depending on where the lesion is located. In general, the higher the lesion is on the spine, the more severe the symptoms tend to be.

Meningocele vs myelomeningocele

Meningocele is a form of spina bifida in which only the meninges and cerebrospinal fluid (CSF) form a sac, without involving the spinal cord.

Myelomeningocele, on the other hand, involves CSF, the spinal cord, nerves, and meninges.

Confirming a diagnosis

Myelomeningocele is diagnosed by an obstetrician or a maternal-fetal medicine specialist and may be detected either during pregnancy or soon after the baby is born.

During prenatal care, according to the American College of Obstetricians and Gynecologists (ACOG), myelomeningocele is usually detected by ultrasound, especially in the second trimester. Maternal serum alpha-fetoprotein (AFP) testing may also help identify an increased risk of spina bifida.

To confirm the diagnosis and assess the severity of myelomeningocele, fetal MRI may be used, especially in cases that may require prenatal surgery.

Amniocentesis may also be recommended to rule out related genetic conditions when the diagnosis has already been confirmed.

After birth, the condition is visible as a sac on the back, and imaging tests such as X-rays, MRI, or CT scans may be used to complete the evaluation.

Possible causes

Myelomeningocele may result from genetic, nutritional, and environmental factors, such as:

• Folic acid deficiency

• A family history of spina bifida or other congenital malformations

• Uncontrolled maternal diabetes

• Obesity before pregnancy

• Exposure to medications during pregnancy, such as anticonvulsants

In addition, elevated body temperature in early pregnancy, such as from prolonged fever, hot tubs, or saunas, may slightly increase the risk of neural tube defects like myelomeningocele.

The exact cause of myelomeningocele is still not fully understood. However, the condition happens because the neural tube does not close completely during fetal development, usually in the first month of pregnancy.

According to the CDC, getting enough folic acid before and during early pregnancy can help prevent neural tube defects such as spina bifida.

Treatment options

Treatment for myelomeningocele may include:

1. Fetal surgery

Fetal surgery is performed before birth, usually between 23 and 26 weeks of pregnancy, to close the opening in the fetus’s back and protect the spinal cord.

This complex procedure may reduce the risk of hydrocephalus, improve leg strength, and increase the child’s chances of walking.

The surgery involves general anesthesia for the mother, opening the uterus, removing the myelomeningocele sac, and closing the defect in layers to protect the spinal cord.

However, not all cases can be treated this way. The medical decision depends on the location of the lesion and whether other abnormalities are present.

2. Postnatal surgery

When fetal surgery is not performed, repair is done shortly after birth, ideally within the first 48 hours, to protect the spinal cord, reduce the risk of infection, and limit further damage.

The surgery is performed in the hospital under general anesthesia. The neurosurgeon first closes the membrane around the spinal cord and then closes the muscles and skin over the defect.

In many cases, there is not enough skin in the area of the myelomeningocele, so the surgeon may remove a small piece of skin from another area, such as the back or buttocks, to close the opening.

Although surgery is effective for repairing the spinal defect, it does not reverse complications that are already present, such as paralysis or incontinence.

In addition, many babies with myelomeningocele may develop hydrocephalus, and in some cases, surgery may be needed after the first year of life to place a drainage system that redirects the fluid to another part of the body.

3. Physical therapy

Physical therapy is essential for children with myelomeningocele because it helps maintain muscle strength, stretch shortened muscles, and improve mobility.

It should be continued as the child grows to support motor development, promote independence in everyday activities, and help reduce bone and joint deformities over time.

Physical therapy is also an important way to help the child adapt to their limitations, such as paralysis, allowing for a more independent life through the use of crutches or a wheelchair, for example.

4. Long-term care

Ongoing care for children with myelomeningocele includes:

• Regular follow-up with a urologist to manage bladder function and prevent urinary tract infections, which may involve catheterization, medication, or surgery

• Orthopedic surgery to correct deformities such as clubfoot, hip dislocation, or scoliosis

• Occupational therapy to support the development of fine motor skills and independence in daily activities

• Neurological monitoring for conditions such as tethered spinal cord, Chiari malformation, or syringomyelia, which may require additional interventions

Long-term care involves coordination among neurosurgeons, orthopedic specialists, urologists, physical therapists, occupational therapists, and developmental specialists throughout childhood and adolescence.

Can myelomeningocele be cured?

Myelomeningocele has no cure. Treatment corrects the spinal defect, helps prevent further damage, and supports the management of existing complications.