Proceedings of the 25th BCTRIMS Annual Meeting

A description of suspected cases of autoimmune encephalitis (AIE) was conducted among patients admitted to two neurological reference hospitals in Curitiba (PR). The objective was to assess the frequency of possible AIE and the positivity of known antibodies in these patients. Samples of suspected AIE were collected for autoimmune panel to determine how many of them had relevant antibodies and met criteria for possible AIE. From 56 patients with suspected AIE, 28 met the criteria for possible AIE, 7 tested positive for antibodies (of these, all met criteria for possible autoimmune encephalitis, except one case with positive anti-GAD, diagnosed with Rasmussen's Encephalitis, with etiological factors not yet defined in the literature and uncertain relationship with the antibody in question); 7 patients are still awaiting antibody results (all meeting criteria for possible autoimmune encephalitis). Amid the patients with positive antibodies, 3 had positive anti-GAD65, 2 had positive anti-NMDA, 1 had positive anti-Yo, and 1 had positive anti-AMPA. Possible autoimmune encephalitis is definided by subacute onset with progression in less than 3 months of deficits in working memory, alteration in mental status, or psychiatric symptoms. Furthermore, it should present at least one of the following: new focal neurological findings, epileptic seizures unexplained by a known previous disease, pleocytosis in cerebrospinal fluid, and/or MRI findings suggestive of encephalitis. However, it is essencial to exclude alternative diagnoses. These findings highlight the importance of considering autoimmune encephalitis in patients presenting with specific clinical criteria. Prompt diagnosis and appropriate management are crucial for improving patient outcomes.