Anti-N-methyl-d-aspartate Receptor Encephalitis Presenting as New-onset Refractory Status Epilepticus Responding to Rituximab in an Adolescent Girl

New-onset refractory status epilepticus (NORSE) is defined as a refractory status epilepticus (SE) in a patient, without a clear acute or active structural, toxic, or metabolic cause, previous active epilepsy, or preexisting relevant neurological disorder. Cryptogenic NORSE cases, often immunotherapy is considered empirically as a favorable response, have been documented in anecdotal case reports. More than half of children with the anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis develop seizures and SE may also occur during the clinical course. But NORSE as a presenting feature of anti-NMDAR encephalitis is extremely rare, as most children present with subacute onset neuropsychiatric and extrapyramidal features. We are describing one such case in an adolescent girl with anti-NMDAR encephalitis, in whom even intravenous anesthetic infusion and first-line immunotherapy including corticosteroid and IVIG were insufficient to achieve seizure control. Super refractory left focal SE in this child resolved after 96 h of injection rituximab, following which intravenous anesthetics could be tapered and child survived with only mild functional limitation on follow-up at 6 months. In children with cryptogenic NORSE, the clinicians need to rule out the cerebrospinal fluid anti-NMDAR antibody. Rituximab is one of the most promising second-line immunotherapy options in children with anti-NMDAR encephalitis for achieving seizure control and inducing long-term remission.