Late Onset MOGAD Optic Neuritis - Case Report and Literature Review

In MOGAD, the age of onset exhibits a biphasic distribution, typically occurring between 5 to 10 years and 20 to 45 years, with a median age of onset ranging from 20 to 30 years.Our patient experienced onset in the sixth decade of life, which is unusual and infrequently reported, and presented with painful blurred vision in both eyes.The fundus exam revealed bilateral optic disc edema accompanied by pyramidal signs.MRI revealed diffused thickening of bilateral optic nerve up to apex with T2 hyper intensity, with focal T2 FLAIR hyper intensities in frontal and parietal white matter, CSF analysis showed marked pleocytosis (2730 cells), 58% polymorph nuclear cells, 42% mononuclear cells, nil-RBC, with increased protein.Given the patient's age and the involvement of the optic nerves and pyramidal tract, along with a cerebrospinal fluid profile that does not showcase lymphocyte predominance, there is a suspicion of NMOSD.However, since the patient tested negative for aquaporin 4, we moved forward with testing for MOG antibodies, which turned out to be positive.Conclusion: MOG optic neuritis is infrequent in the sixth decade of life and may manifest similarly to an opticospinal disorder, affecting both the optic nerve and the brain.