What is spina bifida?
Spina bifida is a birth defect associated with the incomplete development of the spine, particularly the neural tube. The neural tube is a structure that develops into the central nervous system (CNS) and the brain, closing during the third and fourth week of pregnancy. However, spina bifida arises when the neural tube fails to develop and close properly, leaving gaps in the spine, leading to defects in
the spinal cord and damage to nerves. Due to this damage, complications often arise, associated with weakness or paralysis in the lower body, loss of control over urinary and bowel movement, learning difficulties, loss of sensation in the legs leading to accidental injury, alongside several other symptoms.
Factors contributing towards Spina Bifida
Despite the cause of spina bifida currently being unknown, many environmental, genetic and nutritional factors play an important part in the development of the neural tube and the risk of developing spina bifida. Nutritionally, having low folic acid (also known as vitamin B9) intake during pregnancy can lead to the increased risk of a baby developing spina bifida, as well as genetically, where there is a family history of spina bifida, and environmentally, like obesity or diabetes. Knowing this, prevention methods often seek to increase folic acid intake, usually through supplements to prevent the risk of spina bifida in babies. Moreover, treatments are readily available after birth to stop any further damage from occurring by closing the gap in the spine. This is done through using a shunt to drain fluid from the brain. Ongoing treatment is also available throughout life by utilising physiotherapy, mobility aids such as wheelchairs and crutches, and by treating bowel and bladder problems for the child to survive into adulthood and improve their independence. However, currently there are no cures available for spina bifida.
Ongoing research into a potential cure
The CNS is a complex network made up of the brain, spinal cord, and nerves, responsible for communicating messages between the brain and the body. This system is fragile, and when damaged during the progression of spina bifida, damage can become irreversible, meaning broken nerves cannot be repaired. Therefore, there are no current cures for spina bifida due to the fragile nature of the disease. Regardless, a study carried out in 2011 called the Management of Myelomeningocele (a severe but common form of spina bifida) Study (MOMS) was conducted to compare the difference in infant function when treated before or after birth. This study concluded that pre-birth surgery for babies with myelomeningocele greatly improved movement in babies at 30 months compared to babies undergoing surgery after birth, but also carried high risks for both the foetus and mother due to the high risk of the surgery and the need for a highly specialised surgical team which is both expensive and difficult. But, before this revolutionary study took place, spina bifida was a defect fixed on the idea that an individual would forever be paralysed, but this major breakthrough gave hope that early interference using surgery can help make a difference to the lives of many babies with spina bifida. This risky surgery lessened the symptoms of spina bifida, allowing for independent walking and movement.
Since spina bifida is diagnosable before irreversible nerve damage can begin, the foetus can undergo tissue engineering to protect and stimulate regeneration of the foetal spinal cord. Stem cells are unspecialised cells of the human body with the ability to specialise into specific cells and self-renew. A type of stem cell called mesenchymal stromal cells were deemed a suitable candidate for stem cell treatment during a study conducted in 2015. Using these mesenchymal stromal cells, they were used in a large animal model of spina bifida, resulting in increased protection of large neurons within the spinal cord and significant improvements in movement. These promising results suggested that the use of these cells could be sufficient enough to restore the ability to walk in a foetus that would’ve been paralysed.
In 2021, another groundbreaking trial commenced, aiming to reverse the paralysis effect and other symptoms of spina bifida through stem cell treatment during foetal surgery. Three babies with spina bifida were born whilst receiving this one-of-a-kind treatment, and since then have been monitored to assess progression in growth. It is stated that the babies were readily moving their feet after birth, which is astonishing to hear. This is an ongoing study, so results haven’t been published yet, however it could act as an exciting potential cure for spina bifida which could change many people’s lives.
References
Adzick, N. Scott, Elizabeth A. Thom, Catherine Y. Spong, John W. Brock III, Pamela K. Burrows, Mark P. Johnson, Lori J. Howell et al. "A randomized trial of prenatal versus postnatal repair of myelomeningocele." New England Journal of Medicine 364, no. 11 (2011): 993-1004.
Poliwoda, Salomon, Nazir Noor, Evan Downs, Amanda Schaaf, Abigail Cantwell, Latha Ganti, Alan D. Kaye et al. "Stem cells: a comprehensive review of origins and emerging clinical roles in medical practice." Orthopedic reviews 14, no. 3 (2022).
Zakrzewski, Wojciech, Maciej Dobrzyński, Maria Szymonowicz, and Zbigniew Rybak. "Stem cells: past, present, and future." Stem cell research & therapy 10, no. 1 (2019): 1-22.
Wang, Aijun, Erin G. Brown, Lee Lankford, Benjamin A. Keller, Christopher D. Pivetti, Nicole A. Sitkin, Michael S. Beattie, Jacqueline C. Bresnahan, and Diana L. Farmer. "Placental mesenchymal stromal cells rescue ambulation in ovine myelomeningocele." Stem cells translational medicine 4, no. 6 (2015): 659-669.
https://health.ucdavis.edu/news/headlines/worlds-first-stem-cell-treatment-for-spina-bifida-delivered-during-fetal-surgery--/2022/10#:~:text=Three%20babies%20have%20been%20born,trial%20at%20UC%20Davis%20Health. Assessed and Endorsed by the MedReport Medical Review Board