A Review of CSF and Serum Biomarkers to Stratify Acute Spinal Cord Injury Based on Severity of Injury and Prognosis

spinal cord injury (SCI) each year and 300,000 people currently living with an SCI in the United States. The economic burden of such injuries is daunting because the afflicted individual spends an average of 171 days in the hospital over the first 2 years after injury. It has been estimated that the initial hospital expenses average about $95,203 and lifetime medical expenses can range from $500,000 to more than $2 million, depending on the severity and morphology of the injury. In addition to the physical and economic burdens of the SCI, the psychological burden is compounded by uncertainty around the severity and prognosis of an acute SCI. Despite numerous advances in medical, surgical, and rehabilitative care for these patients, long-term outcomes cannot be accurately predicted, furthering the psychological toll such a trauma has on an individual. Additionally, a lack of full understanding about the downstream biochemical pathways that are activated when the spinal cord is injured makes the development of new drugs and therapeutic interventions for these injuries difficult—especially considering there are no easily reproducible objective measurements that can be used for comparison of these novel therapeutic solutions. The pathogenesis of spinal cord trauma can be divided into 2 main types: (1) transection injuries—in which a sharp force penetrates the spinal cord; and (2) contusion traumas—where the spinal cord is crushed or bruised on impact. The pathophysiological timeline of SCI includes 2 phases: primary and secondary injury. The primary injury is the immediate impact of the trauma, including loss of sensory, motor, and autonomic functions, which disrupts the gray matter and microvasculature of the spinal cord. The secondary injury pattern begins to take place immediately after the acute phase, and can continue for months