Myelomeningocele

The human spine is formed by individual vertebrae and connective tissue discs in between. The vertebrae form the spinal canal. There are seven cervical, twelve thoracic, and five lumbar vertebrae. The intervertebral discs are the link between the individual vertebral bodies.

The little joints that link the vertebrae together are known as facet joints. They help to stabilize the spine and, together with the intervertebral discs, allow a certain degree of mobility of the spinal cord. The spinal canal should be wide enough to allow nerve roots to float freely in cerebrospinal fluid. The front border of the spinal canal is built by the vertebral bodies and intervertebral discs, the side by the intervertebral joints (facets) and back by the ligamentum flavum (yellow band) and vertebral arches. Discs consist of an outer fibrous ring (annulus fibrosus), which surrounds an inner gel-like center (nucleus pulposus). The spinal cord and nerve roots lie within the spinal canal. The spinal cord extends downwards approx. to the 1st lumbar vertebra. Below, only nerve roots are present in the spinal canal. At the level of the intervertebral disc the nerve roots pass through the neural root foramina to exit the spinal canal. The spinal cord and nerve roots conduct electric-like signals from the skin and joints to the brain, and process of movement is initiated from the brain to the muscles.

A myelomeningocele is the most severe form of spina bifida. This tissue defect involves the protective sheets of the spinal cord, the bone and skin.

Congenital malformation of the nerve roots and spinal cord

Complete/partial paralysis and numbness of the feet Urinary incontinence or retention

If the myelomeningocele is not covered by skin or at least a thin membrane, reconstructive surgery should be performed within 24 to 48 hours after birth to prevent infection. Prenatal surgery for myelomeningocele reduced the need for shunting and improved motor outcomes but was associated with maternal and fetal risks (PMID 21306277).

Myelomeningocele repair and closure