<b>Cerebrospinal Fluid Neurofilament Light Chain Levels as an Early Marker of Secondary Injury After Acute Spinal Cord Trauma</b>

Background: Traumatic spinal cord injury is a major cause of long-term neurological disability worldwide. Early identification of injury severity and prediction of neurological deterioration remain challenging during the acute phase of trauma. Neurofilament light chain (NfL), a structural protein released during axonal injury, has emerged as a potential biomarker reflecting neuronal damage in various neurological disorders. Objective: To evaluate cerebrospinal fluid neurofilament light chain levels in patients with acute spinal cord trauma and examine their association with neurological severity, radiological injury characteristics, and early neurological deterioration. Methods: This prospective observational study included 60 adult patients presenting within 24 hours of acute traumatic spinal cord injury at a tertiary care hospital. Neurological status was assessed using the American Spinal Injury Association (ASIA) impairment scale, and radiological severity was evaluated using magnetic resonance imaging. Cerebrospinal fluid samples were obtained via lumbar puncture and analyzed for NfL concentration using enzyme-linked immunosorbent assay. Patients were monitored for early neurological deterioration during the first 72 hours. Statistical analysis was performed using SPSS version 26. Results: Mean CSF NfL concentration was 4120 ± 1850 pg/mL. Higher NfL levels were observed in patients with severe neurological impairment, with mean concentrations increasing from 1800 pg/mL in ASIA grade D to 6200 pg/mL in ASIA grade A (p < 0.001). Radiological injury severity also correlated with biomarker levels, increasing from 2100 pg/mL in mild MRI injury to 6100 pg/mL in severe injury (p < 0.001). Patients with early neurological deterioration had significantly higher NfL concentrations compared with stable patients (5800 vs 2900 pg/mL, p < 0.001). Conclusion: Cerebrospinal fluid neurofilament light chain levels are strongly associated with neurological severity, radiological injury characteristics, and early neurological deterioration in acute spinal cord trauma. These findings support the potential role of NfL as an early biomarker of axonal injury and secondary spinal cord damage