This study aims to establish an autoimmune encephalitis cohort and observe the prognosis of patients with different subtypes and subgroups (e.g. epilepsy subgroup and teratoma subgroup ). Clinical characteristics, biological samples, and imaging data will be collected to discover blood and imaging biomarkers for providing support for the treatment, early warning, and outcome prediction.

Inclusion Criteria:

• 1. Gender and age are not limited; 2. Newly diagnosed autoimmune encephalitis according to at least one of the following three criteria:

  1. According to the criteria of Graus et al in 2016, diagnosed as "definite autoimmune limbic encephalitis"
  2. According to the criteria of Graus et al in 2016, diagnosed as "possible autoimmune encephalitis" and typical autoantibodies are detected in serum or cerebrospinal fluid
  3. According to the criteria of Graus et al in 2021, diagnosed as "possible or definite paraneoplastic neurological syndrome" (excluding peripheral nervous system syndrome) 3. The patient or legal representative voluntarily signed the paper informed consent form.

Additional inclusion criteria for patients in the epilepsy subgroup: patients diagnosed with epilepsy secondary to autoimmune encephalitis.

Exclusion Criteria:

• No additional exclusion criteria

Patients with autoimmune encephalitis or paraneoplastic neurological syndrome will be enrolled and no additional exclusion criteria are set.