AQP4 and infectious disease: After receiving clearance from the ethical committee, a retrospective chart review was conducted and records of all the inpatient LETM cases admitted from March 2018 to June 2020 were obtained. From the patient records, the following information was extracted: the demographic profile, clinical presentations, neuroimaging features, cerebrospinal fluid analysis, serum anti-aquaporin-4 (AQP4) immunoglobulin G status, hemogram, infectious disease profile, inflammatory markers, and auto-immune panels.