Current therapy of spinal cord injury

The spinal cord injury (SCI) refers to a condition that the damage to the spinal cord causes neurologic dysfunction. In the case of neurologic dysfunction owing to SCI, its recovery is desperate, and the pathological condition appears as the incompetence of the body. Originally, neural axons can expand even after injury and produce a recovery of the neuronal network [1]. However, the SCI leads to glial scar formation in the peri-injury area. The glial scars physically inhibit neuronal regeneration due to induction of chondroitin sulfate proteoglycan (CSPG) synthesis. Consequently, damaged spinal axons do not regenerate [2]. Other causes have also been reported such as accumulation of keratan sulfate proteoglycan (KSPG) in peri-injury area. Therefore, if neural regeneration and neural axons outgrowth are promoted by transplantation of stem cells or administration of a drugs, the neuronal network can be reconstructed, and it is conceivable that recovery from neurologic dysfunction is possible. However, effective therapeutic strategy for SCI has not yet been established. In clinical practice, spinal cord protective therapy by a bolus intravenous injection of steroid is performed for acute SCI [3]. It remains controversial in clinical effectiveness and still has arguments for and against [4,5]. Additionally, rehabilitation is performed for chronic SCI, and systemic and local hypothermia have also been attempted as SCI management. In recent years, stem cell transplantation and induction of neural axons regeneration have been attempted, and these approaches had a therapeutic effect. However, these approaches require an invasive surgical procedure.