Markers of nerve tissue injury in the cerebrospinal fluid in patients withlumbar disc herniation and sciatica

Study Design, The light subunit of neurofilament protein, S-100 protein, ne uron-specific enolase, and glial fibrillary acidic protein were determined in the cerebrospinal fluid in patients with lumbar disc herniation and in c ontrol patients. Objectives, To determine whether nerve root injury caused by disc herniatio n increases the levels of nerve and glial cell injury markers in the cerebr ospinal fluid. Summary of Background Data. Markers of nerve tissue injury can be analyzed in the cerebrospinal fluid, allowing characterization of the cell types inv olved and the degree of disease in patients with neurologic disorders. Methods. Cerebrospinal fluid samples were obtained by preoperative lumbar p uncture in patients who underwent surgery for lumbar disc herniation and in patients who underwent lower extremity surgery (control group). neurofilam ent protein (light subunit) and glial fibrillary acidic protein were analyz ed by enzyme-linked immunosorbent assay and S-100 protein and neuron-specif ic enolase by radioimmunoassay and luminescence immunoassay, respectively. In the disc herniation group the concentrations of the four markers were ev aluated regarding possible correlation to patient history, computed tomogra phic findings, and clinical findings. Results. Cerebrospinal fluid concentration of neurofilament protein (light subunit) and S-100 were increased in the disc herniation group compared wit h that in control subjects (1158 +/- 383 ng/L vs. 152 +/- 14 ng/L, P < 0.01 ; 1963 +/- 231 ng/L vs. 1003 +/- 152 ng/L, P < 0.05, respectively). No stat istical differences in neuron-specific enolase and glial fibrillary acidic protein concentrations were observed between the groups. Disc herniation pa tients with fewer than 3 months' duration of subjective symptoms had higher neurofilament protein levels than did patients with longer duration. None of the markers was related to preoperative clinical or computed tomographic findings. Patients with persistent neurologic findings at follow-up 2-3 mo nths after surgery had higher levels of neurofilament protein before surger y compared with those without sequelae. Conclusions. Patients with disc herniation and sciatica have increased conc entrations of neurofilament protein and S-100 in the cerebrospinal fluid, w hich indicates damage of axons and Schwann cells in the affected nerve root .