GAD2 and autoimmune encephalitis: The serum and CSF were tested for the presence of autoimmune encephalitis antibodies using cell–based indirect immunofluorescence (Euroimmun, Lübeck, Germany) based on patient findings and clinical presentation (including anti-NMDAR, anti-LGI1, anti-CASPR2, anti-GABABR, anti-AMPRA, anti-IgLON5, anti-DPPX, anti-GAD65, anti-mGluR5, anti-GlyR5, anti-D2R, anti-MOG, and neurexin-3).