The study is to explore the treatment effects and long-term prognosis (12 months and 24
months after immunotherapy) by comparing the early plasma exchange (PE) combined with
medication therapy with the PE after medication immunotherapy in autoimmune encephalitis (AE)
patients, to make clear that the early PE can be more effective than the treatment of PE
after medication immunotherapy. As well as, the study is to explore whether PE is also
effective in AE with autoantibody synthesis in the sheath, positive cerebrospinal fluid
antibody and seronegative.