The Increased Interleukin-6 Levels Can Be an Early Diagnostic Marker for New-Onset Refractory Status Epilepticus.

New-onset refractory status epilepticus (NORSE) is a condition defined as the occurrence of refractory status epilepticus in patients without active epilepsy and no other acute causes of seizure. Although there is evidence that immune-mediated pathogenesis has a pivotal role in the epileptogenesis of NORSE, the diagnosis of NORSE is usually made on the clinical observation because there is no established biological marker suggesting the diagnosis of NORSE. We recently encountered a NORSE patient who was successfully treated with immunotherapy including tocilizumab, an anti-interleukin-6 (IL-6) receptor monoclonal antibody, and the markedly increased levels of serum and cerebrospinal fluid IL-6 were the only laboratory abnormality during the early treatment of the patient.