Manifestations of MOG-IgG-positive optic neuritis are diverse. Despite recurrent attacks with severe vision loss, the majority of patients have significant recovery and retain functional vision long-term.

ObjectiveMyelin oligodendrocyte glycoprotein–immunoglobulin G (MOG-IgG) associated disorder (MOGAD) often manifests with recurrent CNS demyelinating attacks. The optimal treatment for reducing relapses is unknown. To help determine the efficacy of long-term immunotherapy in preventing relapse in patients with MOGAD, we conducted a multicenter retrospective study to determine the rate of relapses on various treatments.MethodsWe determined the frequency of relapses in patients receiving various forms of long-term immunotherapy for MOGAD. Inclusion criteria were history of ≥1 CNS demyelinating attacks, MOG-IgG seropositivity, and immunotherapy for ≥6 months. Patients were reviewed for CNS demyelinating attacks before and during long-term immunotherapy.ResultsSeventy patients were included. The median age at initial CNS demyelinating attack was 29 years (range 3–61 years; 33% <18 years), and 59% were female. The median annualized relapse rate (ARR) before treatment was 1.6. On maintenance immunotherapy, the proportion of patients with relapse was as follows: mycophenolate mofetil 74% (14 of 19; ARR 0.67), rituximab 61% (22 of 36; ARR 0.59), azathioprine 59% (13 of 22; ARR 0.2), and IV immunoglobulin (IVIG) 20% (2 of 10; ARR 0). The overall median ARR on these 4 treatments was 0.3. All 9 patients treated with multiple sclerosis (MS) disease-modifying agents had a breakthrough relapse on treatment (ARR 1.5).ConclusionThis large retrospective multicenter study of patients with MOGAD suggests that maintenance immunotherapy reduces recurrent CNS demyelinating attacks, with the lowest ARR being associated with maintenance IVIG therapy. Traditional MS disease-modifying agents appear to be ineffective. Prospective randomized controlled studies are required to validate these conclusions.

Non-arteritic anterior ischaemic optic neuropathy (NAION) and optic neuritis (ON) may be difficult to distinguish early in their disease courses. Our goal was to determine if specific magnetic resonance imaging characteristics differentiate acute NAION from ON. Neuroradiologists, masked to diagnosis, reviewed the diffusion-weighted imaging (DWI) and post-contrast enhancement (PCE) characteristics of the optic nerve in 140 eyes. PCE and DWI signals of the optic disc alone did not discriminate between NAION and ON. After taking age and sex into consideration, only DWI and PCE of the intraorbital segment of the optic nerve differentiated the two, with ON having the increased likelihood of these findings. Isolated PCE without DWI signal at the optic disc, however, was 100% specific for NAION. This may be the most specific way to radiographically differentiate between NAION and ON in the acute setting.