Definition and Diagnostic Criteria of NORSE

• NORSE is a clinical presentation of refractory status epilepticus (RSE) in individuals without prior epilepsy or relevant neurological disorders.
• Defined by ongoing SE unresponsive to benzodiazepines and at least one antiseizure medication, with no acute structural, toxic, or metabolic cause.
• FIRES (Febrile Infection-Related Epilepsy Syndrome) is a subcategory of NORSE, preceded by a febrile illness 24 hours to 2 weeks before SE onset.
• Diagnosis requires exclusion of known causes (e.g., stroke, infection, intoxication, metabolic derangements).
• Cases are termed "cryptogenic NORSE" if no cause is found, or specified if a cause (e.g., autoimmune encephalitis) is later identified.