To report a novel entity with MOG-associated disease. 

FLAIR-hyperintense lesions in anti-MOG-associated Encephalitis with Seizures (FLAMES) phenotype is a novel entity described in young males with headaches, fluctuating weakness, and seizures. Herein, we describe a young patient with first onset psychosis and status epilepticus with MOG-associated FLAMES syndrome.

Chart and literature review.

A 23-year-old left-handed healthy man presented to an outside hospital with newly-onset headache followed by bizarre behavior, delusions, and visual hallucinations for 1 week. He had multiple seizure episodes during the hospitalization, necessitating treatment with three anti-seizure medications (ASM). Brain MRI revealed cortical and subcortical FLAIR hyperintensities in the left frontal gyrus suspicious for demyelinating etiology. Cerebrospinal fluid analysis showed pleocytosis and no oligoclonal banding. The autoimmune-encephalitis antibody and meningitis/encephalitis panel were negative. Despite empirical treatment with steroids and intravenous immunoglobulins, he continued to deteriorate clinically and was intubated. He was transferred to our institution for further care with modified Rankin score (mRS) of 4. Plasmapheresis was initiated for six sessions. The psychiatric symptoms and cognition improved significantly. No further seizures were recorded. Repeat Brain MRI demonstrated complete resolution of the previous lesions. His MOG titer was positive. Following plasmapheresis he received the induction therapy of rituximab. He was discharged from inpatient rehabilitation with mRS of 1 on maintenance rituximab therapy and ASM taper. At 4 month follow-up he denied any relapse.

MOG-associated disease can be misdiagnosed as viral encephalitis, autoimmune epilepsy, or substance-use disorder in young individuals presenting with atypical symptoms. FLAMES is a novel entity that has been described in the setting of positive MOG titers. Early recognition and treatment with plasmapheresis and anti-B cell immunomodulators is warranted. There is limited longitudinal data available on relapse associated with FLAMES. However, use of immunomodulating therapies such as rituximab and mycophenolate have shown benefit for sustained remission.