This scoping review aims to explore research comparing the efficacy of steroids, IVIG, and PLEX immunotherapies for autoimmune encephalitis (AE) to determine which treatment(s) lead to better clinical outcomes.

Autoimmune encephalitis is a neurological disease treated with several different immunotherapies, including steroids, intravenous immunoglobulin (IVIG), and plasma exchange (PLEX). Steroids are often first-line, but it is unclear whether certain immunotherapies are more clinically efficacious. 

A comprehensive search of the PubMed, Cochrane, and Google Scholar databases from inception to July 1, 2025 was used to identify papers using the following search terms: “autoimmune encephalitis,” “IVIG or intravenous immunoglobulin,” “PLEX or plasma exchange,” and “corticosteroids.” 

We identified 4 publications that fell within our search criteria. 3 of the 4 papers were retrospective studies. The remaining paper was a prospective cohort study. 2 papers examined clinical outcomes in children, and all 4 papers assessed clinical outcomes in the adult population. Half of the studies concluded that PLEX led to clinical improvement and improvement in mRS scores. 1 paper indicated that patients with anti-NMDA AE who received intravenous steroids and PLEX had a significantly greater response rate than patients with anti-LG1/CASPR2 AE. Another paper showed that ⅘ (80%) patients who received steroids and IVIG experienced mRS improvement at discharge compared to 2/4 (50%) patients who received steroids alone. 

There is limited data separately evaluating first-line immunotherapies to assess whether steroids, PLEX, or IVIG are clinically superior. Thus, exploring which immunotherapy correlates most strongly with improved clinical outcomes through additional prospective studies and randomized clinical trials would be beneficial. Additionally, further data on which combinations or cycling of therapies (ie, the “zipper method”) are most clinically efficacious, depending on patient presentation, demographics, and pathogenic mechanism would be crucial in developing more comprehensive treatment protocols.