NTD and TCS: Malformations of the Spinal Cord in Children and Adults

By Richard Ma

One of the most common and life-threatening birth defects are known as neural tube defects (NTDs). These defects are categorized by an opening in the spinal cord or brain during development. Additionally, a less common spinal cord disorder also occurs in adults called adult tethered cord syndrome. This may go undiagnosed until adulthood when pain, sensory, and motor problems occur in a patient’s back.

The two main types of NTDs are spina bifida and anencephaly. Spina bifida occurs when the backbone in a developing newborn does not completely close. If the defect is severe, the affected child could show symptoms including inability to walk, problems with bowel control, and even a tethered spinal cord. Anencephaly occurs when the rostral end of the neural tube fails to close resulting in part of the newborn’s brain to be missing. Infants with anencephaly usually die within a few hours after birth. The exact causes of NTDs are unknown, but various research has determined a correlation with the mother’s health and diet. A major concern when it comes to a mother’s diet is a deficiency in folate (Czeizel et al. 2013). Folate is important in the synthesis of DNA and RNA, and for the production of new cells. In fact, in a study performed by Czeizel, folic acid supplementation prevented NTDs in about 90% of the sample. Additionally, various gene-environment interactions could influence the possibility of NTDs including maternal obesity, diabetes, and cigarette smoking. (McMahon, et al. 2013). Surgery is the main form of treatment for anencephaly and spina bifida (depending on its severity), but future methods of treatment and possible cures are still being researched.

In addition to neural tube defects, tethered cord syndrome (TCS) is a related neurological disorder that also affects the structure of the spinal cord. Although it can occur in children, TCS is more commonly diagnosed in adults. All forms of TCS involve the pulling, or tethering, of the spinal cord at the end of the spinal canal. In adults, tethered cord syndrome results in neurological, urological, and orthopedic symptoms. One study explicated the role of the filum terminale in the development of TCS, and found that in certain cases of TCS, the filum terminale of the spinal cord thickens, resulting in scoliosis (Thompson 2014). Adults affected by TCS normally complain of severe pain in the lower back and legs, weakness and numbness of the muscles, urological irregularities, and inability to maintain bowel control.

Research on treatment of adult tethered cord syndrome is limited, but a few studies have elucidated on the topic. One particular study performed at the Celal Bayar University School of Medicine aimed to observe the results of neurosurgery performed on a group of adult patients with TCS (Selcuki et al. 2015). It was determined that 95% of all patients who underwent the surgery reported an improvement in their leg and back pain. The study showed that TCS should remain a viable diagnosis for patients complaining of back and leg pains, neurological deficits, or urological complaints, and that surgery is a successful treatment of such symptoms.

Although tethered cord syndrome in adults is rarer than neural tube defects in children, an increasing number of research has focused on determining the causes, treatment, and prevention of this disorder. Hopefully, with the advancement of medical technology and the continuing research being done on TCS, the answers to these questions will be revealed. 


References

1. Czeizel, Andrew E. et al. “Folate Deficiency and Folic Acid Supplementation: The Prevention of Neural-Tube Defects and Congenital Heart Defects.” Nutrients 5.11 (2013): 4760–4775. PMC. Web.

2. McMahon, D. M., Liu, J., Zhang, H., Torres, M. E. and Best, R. G. “Maternal obesity, folate intake, and neural tube defects in offspring.” Birth Defects Research Part A: Clinical and Molecular Teratology. 97.2 (2013): 115–122. PMC. Web.

3. "NINDS Tethered Spinal Cord Syndrome Information Page.” National Institute of Neurological Disorders and Stroke (NINDS). National Institute of Health, 28 September 2012. Web.

4. Selcuki, M. et al. “Tethered Cord Syndrome in Adults: Experience of 56 Patients.” Turkish Neurosurgery. 25.6 (2015): 922-929. PMC. Web.

5. Thompson, E. M. et al. “Clinical significance of imaging and histological characteristics of filum terminale in tethered cord syndrome.” Journal of Neurosurgery. 13.3 (2014): 255-259. PMC. Web.