RESUMO
INTRODUCTION: Autoimmune encephalitis (AIE) is a relatively newly described category of immune-mediated diseases involving the central nervous system with a wide spectrum of clinical presentations, ranging from relatively mild or insidious onset of cognitive impairment to more complex forms of encephalopathy with medically refractory seizures. Single or multifocal seizures accompanied by neuropsychiatric symptoms and cognitive or memory impairments are suggestive of clinical features at AIE onset. CASE REPORT: A six-year-old boy presented with repetitive focal seizures, slowly progressive emotional liability, and attention-deficit/hyperactivity disorder-like symptoms. Seizure types varied during the clinical course, sometimes emerging as clusters or statuses. MRI performed during seizure clustering/status revealed moving signal abnormalities. We successfully treated the patient with high-dose intravenous methylprednisolone. Cerebrospinal fluid analysis revealed pleocytosis and marked elevation of antibodies against N-terminals of N-methyl-d-aspartate type glutamate receptor subunits and granzyme B. CONCLUSION: We report a case of moving seizure foci with abnormal MRI findings. Although the onset of psychiatric symptoms slowly progressed to those atypical for AIE, responsiveness to immunotherapy, cerebrospinal fluid pleocytosis, and autoantibodies all indicated AIE. We thus suggest that moving seizure foci and abnormal MRI signals may be findings of AIE.