We introduce four patients who had infectious encephalitis presentation and were subsequently found to have MOG encephalomyelitis with recurrence of symptoms.
Case 1: A 3-year-old, immunocompetent, male with HHV-6 encephalitis, presenting with anorexia, altered mental status, and seizures. His MRI brain demonstrated extensive T2 signal in the cortex, subcortical white matter, and thalamus. He was treated with 21 days of ganciclovir, foscarnet and 5 days of IVIg. Three months later he presented with new diplopia, disconjugate gaze, leg weakness and a new enhancing pontine lesion, requiring IV methylprednisolone (IVMP). MOG antibody testing showed a titer of 1:100. Patient was continued on monthly IVIg without further recurrences.
Case 2: A 9-year-old boy was admitted with fever, AMS, seizures found to be related to Coxsackie B5 meningoencephalitis. As no improvement in his condition was noticed, MOG Ab testing was done with a titer of 1:1000. He was started on monthly IVIG with dramatic improvement.
Case 3: A 5-year-old girl presented with influenza B associated postinfectious ADEM with bilateral optic neuritis, completely recovered with administration of IV methylprednisolone. One month later she re-presented with bilateral optic neuritis, requiring IVMP 6-week oral steroid taper with no further recurrence. About 1 year later her first time MOG antibody testing was positive with 1:100 titer.
Case 4: A 7-year old girl with a prior asymptomatic infection with SARS-CoV-2, subsequently developed status epilepticus, encephalopathy, aphasia with perirolandic and posterior parietal lobe restricted diffusion, cortical edema and EEG with diffuse and focal slowing.SARS-CoV-2 Antibody were positive with MOG Ab titer 1:100.She improved with IVIG and Antiepileptics.
Infectious encephalitis can be a predisposing factor for MOG associated encephalomyelitis. The role of this autoantibody and need for treatment to reduce recurrence requires further evaluation although our patients have improved with maintenance IVIg without recurrence.