Stem cells and chronic spinal cord injury: Overview

Spinal cord injury (SCI) is a severely disabling condition associated with markedly increased healthcare costs. The pathophysiology underlying SCI involves an acute phase of mechanical trauma to the spinal cord leading to a chronic phase mediated by immune pathways that promote injury exacerbation, spreading, and glial scarring. Given their capability to self-renew and differentiate into various mature cell types, stem cells are posited to be uniquely suited to regenerate the components that are damaged in SCI. Stem cell transplantation into animal models of SCI has demonstrated the ability of stem cells to mature into neurons and glia, engraft into recipient neural circuits, and promote functional motor improvement. Promising findings from these pre-clinical studies have motivated clinical exploration of stem cells for use in human SCI patients. Early clinical trials have demonstrated safety and feasibility of transplantation into patients, and improvements in sensory and motor function have been observed. Larger controlled clinical trials will be necessary to continue to assess the potential therapeutic utility of stem cells in chronic spinal cord injury.