Global trends and research hotspots in autoimmune encephalitis: insights from a bibliometric and visualized analysis: 1971-2025

Background: Autoimmune encephalitis (AE) encompasses a highly heterogeneous spectrum of severe immune-mediated neurological disorders. Over the past 50 years, research has expanded rapidly, yet a quantitative synthesis of its evolution, key contributors, and thematic trends is lacking. Here, we provide a comprehensive 50-year, multi-database bibliometric study that systematically maps the full trajectory of AE research-from early descriptions to the current era of mechanism-driven therapeutics-using advanced analytical tools. Methods: We systematically retrieved AE-related publications from 1971 to May 24, 2025 from PubMed, Web of Science, and Scopus. After deduplication, records were analyzed using bibliometric tools (CiteSpace, VOSviewer, Bibliometrix). Analyses included publication trends, national/institutional contributions, author networks, journal distributions, co-citation patterns, keyword co-occurrence, and thematic evolution. Results: Annual publications surged after 2007, coinciding with the discovery of anti-NMDA receptor encephalitis (anti-NMDAR AE), reaching a peak in 2022. The USA and China were the leading contributors by volume, while Spain had the highest average citation impact. The University of Pennsylvania and the University of Oxford emerged as the most productive institutions. Dr. Josep Dalmau is the most prolific author in the field, leading a major collaborative cluster. Frontiers in Neurology published the most papers, while Neurology had the highest H-index. Keyword and thematic analyses confirmed anti-NMDAR AE as the dominant research focus, with intense scholarly interest in its pathogenesis, diagnosis, and immunotherapy. Recent trends highlight emerging topics like COVID-19-associated AE, anti-IGLON5 disease. Conclusions: This study outlines the development, collaboration patterns, and research hotspots in AE. Research continues to center on anti-NMDAR encephalitis, with a growing focus on clinical and therapeutic applications. Future directions include mechanistic studies, biomarker discovery, and advanced immunotherapies.