PP08.4 – 2929: Relapsing central nervous system demyelination in children with myelin oligodendrocyte glycoprotein (MOG) antibodies

Background Myelin oligodendrocyte glycoprotein antibodies (MOG-Ab) are identified in 30–50% of children with acquired demyelinating syndrome (ADS), and in relapsing syndromes such as AQP4-Ab negative neuromyelitis optica spectrum disorder (NMOSD). However, less is known about the wider spectrum and the clinical course of patients who relapse. Objective To evaluate the clinical features of children with MOG-Ab and relapsing disease. Methods Fifty three consecutive children with ADS and MOG-Ab positivity from five paediatric neurology referral centers were identified between 2011 and 2104. Clinical and neuroimaging features were reviewed and the treatment and outcomes evaluated. Results The initial presenting demyelination syndrome, clinical, radiological and investigative features could not distinguish the 13 patients that had a relapsing course from the other monophasic patients. Of the 13 relapsing patients (7 female, median 6.5 yrs; range 3–15 yrs) four presented with monophasic/recurring episodes of acute disseminated encephalomyelitis (ADEM) followed by monophasic/relapsing optic neuritis (ON); three fulfilled criteria for AQP4-Ab negative NMOSD; two had multiphasic ADEM; and four were diagnosed with relapsing remitting multiple sclerosis (RRMS). Intrathecal oligoclonal bands were only detected in 8% (1/12) tested. All 12 patients with abnormal brain MRI had brainstem and/or cerebellar lesion. Eight patients (non-MS) managed on long-term immunosuppression (n=2) and/or prompt acute treatment (n=8) made a complete clinical and radiological recovery at one year from last relapse. All patients with ON (n=8) had a complete visual recovery. Three out of four patients with RRMS are currently undergoing interferon therapy but continue to relapse. Conclusion 25% of MOG-Ab positive patients have a relapsing demyelination, often with a good clinical and radiological recovery. However, 30% (4/13) of this relapsing group may fulfill the diagnosis of MS, although may not have intrathecal bands and appear to have a poor response to MS treatment.