Clinical significance of cerebrospinal fluid nitric oxide concentrations in degenerative cervical and lumbar diseases

Abstract

In animal models of degenerative lumbar disease, inducible nitric oxide synthase (iNOS) is expressed in macrophages and Schwann cells following compression of the cauda equina. We previously reported that NO metabolites (nitrite plus nitrate: [NOx]) in the cerebrospinal fluid (CSF) correlate with postoperative pain relief in patients with degenerative lumbar disease and with neurologic recovery rate postoperatively or after conservative treatment in patients with spinal cord injury. The objective of the present study was to examine the relationship between [NOx] and neurologic severity, and recovery in degenerative cervical and lumbar diseases. Two hundred fifty-seven cases, including 85 patients with cervical compression myelopathy (CCM), 25 with cervical disc herniation (CDH), 70 with lumbar canal stenosis (LCS), and 77 with lumbar disc herniation (LDH), were examined. The CSF [NOx] was measured using the Griess method. Severity of neurologic impairment and clinical recovery was assessed using the Japanese Orthopedic Association score and Hirabayashi's method. [NOx] in CCM and LCS, but not CDH and LDH groups, was significantly higher than that in controls, and correlated with postoperative recovery rates, but not with preoperative neurologic severity. [NOx] significantly correlated with neurologic recovery following surgery for CCM and LCS.