Severe, Refractory Seizures

NORSE (new-onset refractory status epilepticus) and FIRES (febrile infection-related epilepsy syndrome) represent presentations of new-onset status epilepticus without apparent underlying structural, metabolic, or toxic etiology. The cause of NORSE/FIRES remains cryptogenic in up to half of cases, and an abnormal response of the innate immune system has been implicated. Consensus guidelines recommend broad diagnostic investigation and empiric treatment with immunotherapy. NORSE/FIRES is associated with poor outcomes including cognitive impairment and epilepsy, but early recognition and treatment may be important for improving outcomes.