Evaluate the long term outcomes of patients with MOGAD.

Studies of MOGAD have  focused on clinical, serologic and radiologic features with limited data on long term outcomes.

Mayo Clinic Neuroimmunology database included patients meeting the following criteria: (1) Clinical phenotype consistent with MOGAD; (2) Seropositivity for MOG-IgG1 detected by a clinically validated assay (3) ≥8 years follow up.

Twenty nine patients were included (69% female). The median onset age was 17 (range, 2-57) and 17/29 (58%) were (<18 years) at onset.  The presenting manifestations: optic neuritis (ON), 13 (unilateral, 9;bilateral, 4 ), acute disseminated encephalomyelitis (ADEM), 9 (31%); transverse myelitis (TM), 4 (14%), concomitant ON/TM, 3(10%). The median (EDSS) at attack nadir was 4.0 (range, 1-8.5). By last follow-up (median, 14 years; 9- 31), 25 patients (86%) had developed ≥1 relapse (median, 5; 1-14):  ON, 13 (unilateral median; 9 range, 3-20, bilateral median ; 2, range 2-7); TM, 5 (median 3, range 2-6); ADEM, 4; encephalitis, 4; and brainstem attack, 3. The annualized relapse rate was 0.33 (0.06-1.47).  Of 13 patients with ON, 9 (70%) had a visual acuity of 20/20 and one patient had visual acuity > 20/200. Two patients required assistance with ambulation, none were wheelchair dependent (despite 25% requiring wheelchair at nadir). Seven (44%) had permanent bladder dysfunction. Median EDSS at last follow-up was 2.5 (range, 0-10). One patient died from recurrent encephalomyelitis. Brain MRI at last follow up (median of 6 years from onset; 1-11) in 25 patients was normal in 18 (72%), residual white matter hyperintensities, 4 (16%), atrophy, 3 (12%).

Long term outcomes of MOGAD are generally good despite a high relapse frequency. We did not detect a secondary progressive course and most patients had a normal MRI head at last follow up, providing further distinction from MS. No predictors of disability were identified.