FLAIR-hyperintense lesions in anti-MOG-associated encephalitis with seizures presenting with postictal purpura and rhabdomyolysis: a case report.

FLAIR-hyperintense lesions in anti-MOG-associated encephalitis with seizures (FLAMES) represent a rare and distinctive clinico-radiological syndrome. Here, we report the case of a 35-year-old man who presented with sudden-onset generalized tonic-clonic seizures. Brain magnetic resonance imaging revealed cortical FLAIR hyperintensities in the right parietal lobe. During hospitalization, he developed scattered petechiae over the neck and chest, accompanied by elevated creatine kinase (CK) levels, findings that initially raised concern for systemic vasculitis or inflammatory myopathy. Given the close temporal relationship to the seizures, together with negative autoimmune and infectious evaluations, these abnormalities were ultimately interpreted as postictal purpura and seizure-associated rhabdomyolysis. Subsequent investigations confirmed serum positivity for anti-MOG antibodies, while antinuclear antibody profiling, vasculitis-related markers, and microbiological screening were all negative. After high-dose intravenous methylprednisolone therapy, seizure activity was controlled, the petechial rash resolved, CK levels normalized, and the cortical lesions showed marked regression on follow-up imaging. This case highlights that FLAMES may be complicated by postictal purpura and rhabdomyolysis, underscoring the potential for diagnostic confusion with systemic inflammatory disease.