The early risk of multiple sclerosis after optic neuritis

Serial brain MRI was performed in 53 patients with clinically isolated optic neuritis. Using clinical and imaging evidence for relapse, multiple sclerosis developed within a mean of 12 months in 19 of 34 cases (56%) with brain lesions at presentation, and in only 3 of 19 cases (16%) without (Relative Risk = 6.8, p less than 0.005).