LGI1 and viral encephalitis: AE subtypes are identified according to the autoantibodies, such as anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, anti-leucine-rich glioma-inactivated protein 1 (LGI1) encephalitis, anti-contactin-associated protein-like 2 antibody (CASPR2), and anti-α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor encephalitis (AMPAR) encephalitis [2].