To assess the frequency, characteristics and outcomes of late adult onset Myelin oligodendrocyte glycoprotein antibody-associated disease (LO-MOGAD) and compare to early adult onset (EO-MOGAD).
Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) can occur at any age, but data regarding LO-MOGAD are scant.
We included 107 patients, representing 25% of the patients in the Mayo Clinic MOGAD database (n=436). Median age at onset was 59 years-old (range: 50-88) and 71 (66%) were female. Medical comorbidities were noted in 86/105 (83%). Optic neuritis was the most frequent phenotype at onset (77/107, 72%); median Expanded Disability Status Scale (EDSS) at nadir was 3 (range:1-9). In 32/107 (30%) cases a potential trigger was noted, mostly infections. In 32 patients (30%) an alternative diagnosis was assigned, most commonly giant cell arteritis (n=15). By a median follow-up of 22 months (range: 0-306), 50 (47%) patients had a relapsing course, and preventive treatment was administered in 53 (50%). Medication side effects were common (41/107, 38%). Follow-up duration predicted relapses; EDSS at nadir predicted residual disability. No differences were observed in patients aged 50-59 versus ≥60 years. Compared to EO-MOGAD, LO-MOGAD had more optic nerve, brainstem/cerebellar involvement and cognitive decline (p<0.05) and less frequent myelitis (p<0.05). EDSS and relapsing disease course were similar.
LO-MOGAD accounts for 1/4 of cases and optic neuritis is the dominant phenotype. In this age group, MOGAD is under-recognized and frequently misdiagnosed. Outcomes in LO-MOGAD and EO-MOGAD are comparable.