Previously, scholars called the seizures secondary to autoimmune encephalitis（AE） "autoimmune related epilepsy", but the seizures secondary to AE are usually controlled after the improvement of encephalitis, which does not meet the "persistent" characteristics of epilepsy. Only a subset of patients with seizures lasting several years require long-term Antiseizure medications (ASM). In 2020, the International Coalition against Epilepsy classified it as "acute symptomatic seizure secondary to AE". ASSAE) and autoimmune-associated epilepsy (AAE) . The former is caused by AE, which has clinical manifestations of AE at the same time as epileptic seizures at the beginning or recurrence. The proportion and type of epileptic seizures are different due to different causes, and epileptic seizures are also controlled after the disease is controlled. The latter is that after adequate immunotherapy, there are still persistent seizures, and there is no obvious evidence of inflammatory activity, this type of patient application ASM and immunotherapy is not effective.

Secondly, with the deepening of AE research, gradually found that some AAE can still be ASMs cure, such as carbamazepine, ocasepine, lakaosamine. On the one hand, it works by influencing cellular and humoral immune responses. On the other hand, effectiveness of sodium channel blockers in focal epilepsy. Lacosamide is a slow sodium channel blocker that belongs to the third generation of ASM. It has a short half-life and can be quickly increased to an effective dose with a low incidence of adverse reactions. Therefore, the investigators chose to add oral antiepileptic therapy with lacosamide in AAE populations to observe efficacy and safety.

Inclusion Criteria:

1. Confirmed autoimmune encephalitis (2016,Lancet);
2. Meet the classification criteria for epilepsy (2017,International League Against Epilepsy);
3. Patients who still have seizures after taking ASM after the control of AE disease were included in the third part of the study;
4. All patients volunteered and signed an informed consent form;

Exclusion Criteria:

1. Incomplete key clinical data;
2. People with epilepsy or other intracranial diseases before diagnosis;
3. There is no epileptic author during the onset of autoimmune encephalitis;

Patients with confirmed autoimmune encephalitis