Written By THT Editorial Team
Reviewed by Dr. Aayush Shrestha, Orthopaedic & Spine Surgeon, MS Ortho, FSS
Spinal cord injury (SCI) is a devastating condition that can cause permanent loss of function and affect mobility, senses, and many other bodily functions.Globally 15 million people are living with SCI with the majority of cases due to preventable trauma ( WHO,2024). Beyond the physical limitations, SCI also has a profound impact on the psychological well- being of individuals. Adults living with SCI have a significantly raising risk of depression and anxiety (Peterson et al., 2022). Furthermore, SCI imposes a substantial financial burden on society. The estimated lifetime burden of per individual with SCI ranges from 1.5 to 3.0 million due to long term care and loss of employment ( Diop, Epstein, & Gaggerro, 2021) Despite significant advances in medical technology and rehabilitation techniques, SCI continues to face many challenges in treatment and recovery. However, recent research has revealed new approaches and treatments that may improve outcomes for patients with SCI.
Stem Cell Therapy: Building New Pathways
One of the most promising areas of SCI research is the use of stem cells. Stem cells are unique because they are like versatile building blocks that can become different types of cells, including the nerve cells (neurons) that make up the spinal cord. Researchers are investigating the use of different stem cell types in the treatment of SCI, with some of the most common being:
- Mesenchymal stem cells (MSCs): These cells are found in bone marrow and can develop into several cell types, including bone, cartilage, and fat cells. In SCI research, MSCs have shown promise in promoting nerve regeneration and reducing inflammation.
- Neural stem cells (NSCs): These stem cells are already on the path toward becoming cells of the nervous system. NSCs hold the potential to directly replace damaged neurons and help rebuild the communication pathways in the injured spinal cord.
A recent study published in Stem Cell Reports showed that transplanting stem cells called mesenchymal stem cells (MSCs) improved the ability to move and promoted nerve regeneration in rats with SCI (Wang et al., 2021). The researchers found that MSCs helped new nerve cells grow, improved the overall health of the spinal cord, and even contributed to forming new connections across the injury site.
Another study recently published in Nature Communications showed that transplanting neural stem cells (NSCs) improved bladder function in rats with SCI (Chen et al., 2020). The researchers found that the NSCs transformed into neurons that became part of the spinal cord circuitry, improving signaling between the bladder and the brain.
Boosting Nerve Growth with Neurotrophic Factors
In addition to stem cells, researchers are also investigating the use of neurotrophic factors in the treatment of SCI. Neurotrophic factors are like special “fertilizers” for nerve cells, supporting them in multiple ways:
- Promoting Growth: They stimulate the development of new neurons and encourage the branching of nerve fibers, helping them form connections.
- Supporting Survival: Neurotrophic factors help existing neurons stay healthy and function optimally.
- Reducing Inflammation: Some neurotrophic factors can help calm the excessive inflammation that occurs after a spinal cord injury.
A recent study published in the journal Nature Communications showed that administering a neurotrophic factor called brain-derived neurotrophic factor (BDNF) improved the ability to move and promoted nerve regeneration in rats with SCI (Li et al., 2021). BDNF helped new neurons grow, encouraged connections within the injured spinal cord, and improved the overall health of nerve tissue.
Electrical Stimulation: Re-wiring the Connection
In addition, researchers are also investigating the use of electrical stimulation in the treatment of SCI. Electrical stimulation involves the use of electrical currents to stimulate nerves and muscles. This type of stimulation is already used in other areas of medicine, such as pacemakers for the heart, and researchers are exploring how it could be adapted to help in the recovery from spinal cord injury.
A recent study published in Scientific Reports showed that the use of electrical stimulation improved the ability to move and promoted nerve regeneration in rats with SCI (Zhang et al., 2020). The researchers believe that electrical stimulation works by encouraging surviving nerve fibers to sprout new branches, facilitating the formation of alternative signal pathways around the damaged area.
Calming the Immune Response for Better Healing
In addition to these treatments, researchers are also investigating the role of immune cells in SCI. SCI triggers a complex immune response within the body, and while some aspects of this response are helpful for healing in the acute phase, prolonged inflammation can actually further damage the spinal cord. Researchers are investigating ways to modulate the immune response (adjust its activity) to improve healing and reduce long-term damage.
A recent study published in the journal Nature Neuroscience showed that targeting a type of immune cell called microglia improved motor function and nerve regeneration in mice with SCI (Zhou et al., 2021). Microglia are like the clean-up crew of the nervous system, but after injury, they can become overactive and contribute to tissue damage. This study suggests that finding ways to calm microglia activity could be a beneficial treatment strategy.
Hope for the Future
In summary, recent studies have identified several promising treatments for SCI, including stem cell transplantation, neurotrophic factors, electrical stimulation, and immune modulation. Although these therapies are still in development, they hold great promise for improving outcomes for patients with SCI. Further research is needed to fully understand these treatment options, optimize their delivery, and develop safe and effective treatments for SCI.
REFERENCES
- World Health Organization. (2024, April 16). Spinal cord injury. WHO. https://www.who.int/news-room/fact-sheets/detail/spinal-cord-injury
- Peterson, M., Meade, M., Lin, P., Kamdar, N., Rodriguez, G., Mahmoudi, E., & Krause, J. (2022, February 7). Mental health is an issue for people with spinal cord injury Chronic pain makes it worse University of Michigan Institute for Healthcare Policy & Innovation. Retrieved from https://ihpi.umich.edu/news/mental-health-issue-people-spinal-cord-injury-chronic-pain-makes-it-worse
- Diop, M., Epstein, D., & Gaggero, A. (2021). Quality of life, health and social costs of patients with spinal cord injury: A systematic review. European Journal of Public Health, 31(Supplement_3), ckab165.177. https://doi.org/10.1093/eurpub/ckab165.177
- Wang, L., Ji, H., Zhou, J., Xiong, Y., and Zhang, Y. (2021). Mesenchymal stem cell transplantation improves motor function and promotes nerve regeneration in a rat model of spinal cord injury. Stem Cell Reports, 16(5), 1159-1174.
- Chen, J., Zhang, Z., Zhang, L., Li, Y., Liu, Q., Lu, D. … and Wang, L. (2020). Neural stem cell transplantation improves bladder dysfunction after spinal cord injury in rats. Nature Communication, 11(1), 1-14.
- Li, L., Xiao, Y., Liu, X., and Chen, J. (2021). Brain-derived neurotrophic factor rescues neuronal deficit in a rat model of spinal cord injury through PI3K/AKT signaling. Nature Communications, 12(1), 1-16.
- Zhang, L., Xiong, Y., Mahajan, and Ji, H. (2020). Electrical stimulation promotes functional recovery after spinal cord injury by increasing neurogenesis and inhibiting microglia-mediated inflammation. Scientific Reports, 10(1), 1-15.
- Zhou, K., Zhong, S., Liang, S., and Yao, F. (2021). Targeting microglia to treat neurological diseases. Nature Neuroscience, 24(4), 421-433.