Does Immunotherapy Work for New-Onset Refractory Status Epilepticus? A Pooled-Analysis of Available Literature

Objective: To determine whether immunotherapies improve outcomes in patients with New-Onset Refractory Status Epilepticus (NORSE). Background: is characterized by persistent seizures without identifiable etiology in patients without history of epilepsy, lasting greater than 24-hours despite treatment with first- and second-line therapies. Its management is challenging and controversy surrounds the utility of We identified all available case series describing the use of immunotherapies (pulse-dose steroids, intravenous immunoglobulins, plasmapheresis, and/or chemotherapy) in NORSE and compared outcomes in patients that received immunotherapy with those that did Methods: This is a pooled analysis of previously published case-series. Poor outcome was defined as death, vegetative state or inability to care for self; favorable outcome was any other outcome. Studies were excluded if: 1) u003c2 patients described; 2) no patients treated with immunotherapy. Results: Eleven studies (including ours - Khawaja et. al., 2015, Epilepsy and Behavior) were included in the analyses; four were pediatric case-series that described a syndrome similar to NORSE in adults. Patients were divided into two categories based on whether or not immunotherapy was used. The total number of patients was 94, with 45 that received any immunotherapy and 49 that did not. Of the patients receiving immunotherapy, 19/45 (42[percnt]) had favorable outcomes compared to 10/49 (20[percnt]) of those untreated. Patients who received immunotherapy had better outcomes (chi-square; p=0.02217). Conclusions: Based on pooled analysis conducted on data from case-series, immunotherapy may be associated with favorable outcomes defined as any outcome other than death, vegetative state or inability to care for self. Due to heterogeneity in patient demographics, NORSE etiologies, diagnostic criteria and treatment, these results should be interpreted with caution, and only a class-IV level of evidence is assigned. These results support the design of prospective randomized placebo-controlled clinical trials to assess the efficacy of immunotherapy in NORSE. Disclosure: Dr. Khawaja has nothing to disclose. Dr. Qadri has nothing to disclose. Dr. Qaiser has nothing to disclose. Dr. DeWolfe has nothing to disclose. Dr. Miller has nothing to disclose. Dr. Szaflarski has nothing to disclose.