Prognosis of optic neuritis with special reference to cerebrospinal fluid immunoglobulins and measles virus antibodies.

Forty-eight patients with optic neuritis (ON), first seen in 1970 to 1973, were neurologically and neuroophthalmologically reexamined after 7 to 10 years. Twenty-seven patients (56%) had probable MS, and 9 (19%) had possible MS. During the attack of ON, the cerebrospinal fluid (CSF) samples and serum/CSF measles antibody ratios were studied. Twenty patients had increased relative immunoglobulin G (IgG) (% of total protein) in their CSF; 19 of these had probable or possible MS. However, 17 of 28 patients with a normal relative IgG value had also developed MS. CSF electrophoresis was abnormal in 20 patients with ON; reexamination showed that 19 had probable or possible MS. Sixteen of 27 patients with normal electrophoresis had also developed MS. Serum/CSF measles antibody ratio had decreased in 19 patients; 13 of these had probable MS and 3 had possible MS. Of 29 patients with a normal measles antibody ratio, 14 had probable MS and 6 had possible MS. The conclusion is that examination of the CSF in ON gives valuable prognostic information because increased relative IgG, abnormal electrophoresis, or a decreased measles antibody ratio implies a high risk of developing MS. A normal CSF does not, however, rule out the possibility of dissemination.