Split spinal cord malformation (SSCM) is a rare form of spinal dysraphism in which a person is born with splitting, or duplication, of the spinal cord. It may be characterized by complete or incomplete division of the spinal cord, resulting in two 'hemicords.'

There are two types of SSCM. In type I, each hemicord has a full protective covering (thecal sac) and they are separated by a bony structure, forming a double spinal canal. In type II, the two hemicords are surrounded by one thecal sac and there is a single spinal canal.

While SSCM is present from birth, it may become apparent at any age and is more common in women than in men. Some people may not have symptoms, while others may have a tethered cord and/or various other spinal abnormalities. Symptoms vary and may include back pain, bladder dysfunction, and leg pain or weakness. SSCM is thought to be caused by abnormal formation of the notochord and neural tube (which ultimately form the brain and spinal cord) very early in embryonic development.

Treatment may include surgery for release of a tethered cord, and/or physical therapy for neurologic problems or pain.

We are not aware of risk factors during pregnancy known to be associated with split spinal cord malformation (SSCM) specifically. There also doesn't appear to be a unified risk factor for all types of closed spinal dysraphism (which includes SSCM).

Folic acid deficiency has been clearly associated with open spinal dysraphism, but no studies have addressed whether there is a relationship between folic acid deficiency and closed spinal dysraphism. Likewise, maternal exposure to certain medications (anticonvulsant drugs) has been associated with spinal dysraphism in the fetus, but human studies have generally focused on open, rather than closed, spinal dysraphism.

We are not aware of evidence that maternal exposure to antibiotics is associated with SSCM.

Studies regarding risk factors for spinal dysraphism (which includes SSCM) have primarily focused on open spinal dysraphism. Folic acid deficiency has been clearly associated with open spinal dysraphism, but no studies have addressed whether there is a relationship between folic acid deficiency and closed spinal dysraphism. We are not aware of information about preventing SSCM and other types of closed spinal dysraphism.

People with spinal dysraphism with a significant spinal defect reportedly show an increased incidence of open neural tube defects (ONTDs) in their children. Generally, women who may have an increased risk to have a child with a neural tube defect are advised to take a higher dose of folic acid before and during the first three months of pregnancy.

People with a family history of SSCM or any other birth defect are encouraged to speak with a genetic counselor or other genetics professional.