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Antibodies to myelin oligodendrocyte glycoprotein (MOG) are associated with diverse manifestations of central nervous system autoimmunity. The cardinal clinicoradiologic manifestations include acute optic neuritis, TM, ADEM, and NMOSD. A cortically-based encephalitis is a rare manifestation of MOG-associated Disease, and is typically unilateral. Here we report an atypical case of a young female presenting with palatal myoclonus and bilateral multifocal cortical-based inflammation, and high serum titers of anti-MOG-IgG.

A 29 year old African American female developed palatal/oral trembling with dysphagia, language difficulties, and gait instability. Her oral trembling was consistent with palatal myoclonus. MRI demonstrated bilateral, cortically based hyperintensities, in addition to multiple non-enhancing and enhancing lesions in the juxtacortical regions, brainstem and spine. CSF examination showed lymphocytic-predominant pleocytosis with mildly elevated protein and oligoclonal bands. Serum testing for MOG-IgG antibodies using a cell-based assay revealed markedly high titers that exceeded the upper limit of detection. A brief course of high dose intravenous steroids resulted in dramatic clinical and radiographic improvement. The patient was subsequently started on CD-20 depleting maintenance therapy (Rituximab) with no clinical relapses at 8 month follow-up.

We present the first case description of palatal myoclonus in association with MOG antibodies. Anti-MOG-associated disease is an expanding entity with diverse clinical phenotypes involving the brain, brainstem, optic nerves and spinal cord. Description of atypical cases is pivotal to improving our understanding of the disease. Although characteristic clinical and radiologic accompaniments have been described, the diagnosis remains largely based upon the detection of MOG-antibodies using improved testing methods via cell-based assays. When faced with unusual cases of demyelinating pathology, clinicians should keep a high index of suspicion for MOG-antibody disease, as prompt recognition and treatment can result in better outcomes.