Clinical, imaging, and recurrence analysis of myelin oligodendrocyte glycoprotein antibody-associated disease with initial presentation as meningoencephalitis in children: a single-center retrospective study.

BACKGROUND

Myelin oligodendrocyte glycoprotein (MOG) antibody-associated disease (MOGAD) is a neuroinflammatory disorder with a heterogeneous phenotype. MOGAD, presenting with meningoencephalitis, has been described, with limited data on the clinical and radiographic features in children.

OBJECTIVE

We aimed to comprehensively investigate the clinical and radiographic characteristics of the MOG antibody-associated meningoencephalitis in children and to identify any magnetic resonance imaging (MRI) markers associated with relapse.

MATERIALS AND METHODS

This was a single-center, retrospective study. All data for pediatric patients (age of onset < 18 years) diagnosed with MOGAD at our hospital from January 2018 to January 2024 were reviewed. Patients with initial clinicoradiological constellations consistent with meningoencephalitis were included in the analysis and subsequently classified into monophasic and multiphasic groups based on the presence or absence of clinical relapses.

RESULTS

A total of 53 children (23% of our MOGAD cohort; age range, 2.7-16.4 years; median age, 11.4 years; 21 females) were included; among them, 21 (40%) presented with a multiphasic course. Within the entire cohort, the common clinical manifestations included seizures (37 (70%)), headache (35 (66%)), and fever (31 (58%)). MRI revealed unilateral involvement in 35 (66%) and bilateral involvement in 18 (34%). Frontal lobe involvement (45 (85%)) was the most predominant MRI pattern. On T2-weighted fluid-attenuated inversion recovery (FLAIR) images, cortical hyperintensity was observed in 46 (87%) patients, leptomeningeal linear hyperintensity in 28 (53%), and subcortical FLAIR hypointensity in 51 (96%). Diffusion restriction (4 (8%)) was uncommon. Meningeal enhancement was observed in 88% (38/43). Compared with the monophasic group, the multiphasic group demonstrated greater proportions of parietal (P = 0.023), occipital lobe (P = 0.016), and hemispheric (P = 0.023) involvement, as well as a greater median number of involved lobes (P = 0.011). Multivariate logistic regression analysis, adjusted for age and sex, revealed that a greater number of involved lobes was an independent risk factor for relapse (P = 0.010, odds ratio (OR) = 1.547).

CONCLUSIONS

Subcortical FLAIR hypointensity, also known as the "dark white matter" sign, is a particularly prominent imaging finding in children with MOG antibody-associated meningoencephalitis. In pediatric patients with epilepsy of unknown etiology, the concurrent presence of meningocortical abnormalities and the "dark white matter" sign on MRI is highly suggestive of this phenotype. A more extensive meningocortical lesion burden is associated with a higher risk of relapse.