Can CSF predict the course of optic neuritis?

To discuss the implications of CSF abnormalities for the course of acute monosymptomatic optic neuritis (AMON), various CSF markers were analysed in patients being randomly selected from a population-based cohort. Paired serum and CSF were obtained within a few weeks from onset of AMON. CSF-restricted oligoclonal IgG bands, free kappa and free lambda chain bands were observed in 17, 15, and nine of 27 examined patients, respectively. Sixteen patients showed a polyspecific intrathecal synthesis of oligoclonal IgG antibodies against one or more viruses. At 1 year follow-up five patients had developed clinically definite multiple sclerosis (CDMS); all had CSF oligoclonal IgG bands and virus-specific oligoclonal IgG antibodies at onset. Due to the relative small number studied at the short-term follow-up, no firm conclusion of the prognostic value of these analyses could be reached. CSF Myelin Basic Protein-like material was increased in only two of 29 patients with AMON, but may have potential value in reflecting disease activity, as the highest values were obtained among patients with CSF sampled soon after the worst visual acuity was reached, and among patients with severe visual impairment. In most previous studies of patients with AMON qualitative and quantitative analyses of CSF IgG had a predictive value for development of CDMS, but the results are conflicting.