Approach to new-onset refractory status epilepticus (NORSE) and febrile infection-related epilepsy syndrome (FIRES)

Abs: antibodies; ASM: antiseizure medication; CNS: central nervous system; CSE: convulsive status epilepticus; CSF: cerebrospinal fluid; CT: computed tomography; EEG: electroencephalography; FLAIR: fluid-attenuated inversion recovery; IL: interleukin; IVIG: intravenous immune globulin; IV: intravenous; MRI: magnetic resonance imaging; NCSE: nonconvulsive status epilepticus; NMDA: N-methyl-D-aspartate; PET: positron emission tomography; RSE: refractory status epilepticus; SE: status epilepticus.

* Refer to UpToDate topics on treatment of CSE, NCSE, and RSE.

¶ Findings suggestive of autoimmune or paraneoplastic encephalitis include subacute onset of short-term memory deficits, altered mental status, or psychiatric symptoms; new focal CNS deficits; new-onset seizures; CSF pleocytosis; and brain MRI findings compatible with demyelination or inflammation, such as hyperintense FLAIR signal involving gray matter and/or white matter. Refer to UpToDate topics on immune-mediated encephalitis for full details.

Δ The situation is not hopeless. Targeting the underlying mechanisms of NORSE with both specific and nonspecific therapies has proven successful in some cases. The options that we provide are not exhaustive; other therapies targeting the underlying immunologic disorder and/or RSE can be considered. However, there is scant evidence for these options.