RESUMO
Background: Anti N-methyl-D-aspartate (NMDA) receptor encephalitis is an immune mediated disorder. Case characteristics: A previously healthy 14-year-old girl presenting with generalized tonic clonic seizures and altered behavior. Observation: In view of refractory seizures, hallucinations, psychobehavioral and catalepsy like symptoms, and CSF showing lymphocytic pleocytosis, possibility of autoimmune encephalitis was considered. Serum was positive for anti-NMDA receptor antibodies. Outcome: She recovered completely in six months without any sequelae. Conclusion: Anti-NMDA receptor encephalitis - a potentially treatable disease - should be considered in differential diagnosis of encephalitis when acute behavioral changes, seizures or dyskinesias are present.