Elevated cerebrospinal fluid proteins in sciatica caused by disc herniation.

We carried out a study of cerebrospinal fluid (CSF) proteins in 180 patients with sciatica caused by lumbar disc herniation to elucidate further the degree and mechanisms of protein elevations. The 63 controls were patients with tension headache or migraine without aura. The CSF/serum albumin ratios were higher in the patients (mean 8.84, SD 5.16) than in the controls (mean 5.60, SD 2.33). Similar differences were found for the CSF/serum IgG ratios and the CSF-total proteins. The CSF/serum albumin ratios, CSF/serum IgG ratios and the CSF-total protein concentrations were higher in men than in women among the patients. We suggest that the significant difference in ratio parameters between patients and controls indicates a leak of plasma albumin, most likely IgG, into the CSF in patients with sciatica. The leak was more pronounced in men. Also in the control group the CSF/serum albumin and CSF/serum IgG ratios were higher in men.