Among the 317 patients diagnosed with LGI1-Abs during the study period, 107 (34%) were excluded due to short follow-up or insufficient clinical information (85/107, 79%), concomitant positivity for other neural antibodies (13/107, 12%), isolated peripheral nervous system involvement (7/107, 7%), and diagnosis of Alzheimer disease concomitant with encephalitis diagnosis (2/101, 2%). This evidence concerns the gene LGI1 and viral encephalitis.