Epilepsy type of unknown cause is presumed to be due to an underlying cause not diagnosed yet. 1,2 An important area that deserves to be researched is the presence of specific antibodies associated with seizures. 3 Those types of epilepsies are either associated with signs and symptoms of encephalitis or presented primarily as recurrent seizures without features of encephalitis. 4 Symptoms as isolated seizures occur more frequently in children, are commonly of focal type, with an insidious onset or maybe aggressive, very frequent and prolonged with status epilepticus modality. 5 N-methyl-D-aspartate receptor (NMDAR) is a neuronal surface antibody and one common type implicated in disorders like epilepsy. 6 In the human brain, the NMDAR is a ligand of glutamate, the primary excitatory neurotransmitter. Its major role is in synaptic plasticity. Therefore, testing anti-NMDAR antibodies in children with seizure