P1685: Presence of Myelin Oligodendrocyte Glycoprotein antibodies (MOG-ab) in Paediatric Acquired Demyelinating Disease Does Not Confer Additional Risk of Poor Long-Term Psychological Outcomes.

Introduction: Acquired demyelinating syndromes (ADS) in childhood disrupt brain networks, affecting cognitive development. Even monophasic ADS in children can result in long-term neuropsychological sequalae. The role of myelin oligodendrocyte glycoprotein antibodies (MOG-ab) in long-term neuropsychological outcomes remains uncertain, but less severe difficulties have been reported. Previous research focused on relapsing patients and utilised retrospective, or clinician reported outcomes.
Objectives/Aims: This study assessed long-term (>18months post onset) neuropsychological sequalae of MOG-ab positive patients compared to other ADS cases using standardized assessments.
Methods: 28 children aged 6-15yrs participated, including MOG-ab positive ADS patients (n=8), antibody negative ADS patients (n=9) from Birmingham Children’s Hospital (mean time since onset (SD) = 2.72yrs (2.95), monophasic/multiphasic = 12/5) and community controls (n=11). Neuropsychological assessment included the WISC-V (Wechsler Intelligence Scale for Children) and academic ability evaluated using the WIAT—III (Wechsler Individual Achievement Test).
Results: No significant differences were found between ADS patients with or without MOG-ab, or with healthy controls. Additionally, controlling for age at onset, time since onset or disease course did not reveal differences.
Individual level analysis (clinically concerning impairment defined as 1SD below test average) showed 14% of MOG-ab patients and 22% of ADS patients had clinically concerning IQ scores. Highest frequency of impairment for the MOG-ab patients was in processing speed difficulties (38%), whilst for ADS patients, this was visual spatial and working memory skills (44% each). Academic impairments were seen in individuals in the ADS group (13% math, 38% reading), and MOG-ab patients (13% math, 0% reading).
In the MOG-ab group, only 3/8 patients demonstrated an impairment on ⩾1 subtest of the WISC and WIAT (median no. of affected subtests=1, range=1-5). Conversely, the antibody negative group had 8/9 patients with impairment on ⩾1 subtests (median=2, range=1-7).
Conclusion: Group level analysis showed typical functioning three years after disease onset. However, individual-level data highlights a subset of patients with ongoing difficulties, more so in ADS patients without the antibody. Further research is needed to understand the differential impact of MOG-ab in pediatric acquired demyelinating disease and its implications for long-term neuropsychological outcomes.

Presented as Late Breaking EPoster at MSMilan2023 (https://ectrims.eu/msmilan2023/)