Autoimmune encephalitis involve autoantibodies targeting central nervous system, and particularly the synapse or its structure like for LGI1 protein. Anti-LGI1 encephalitis is revealed by an inflammation of the limbic system, with mainly temporal lobe, faciobrachial dystonic or generalized seizures, and cognitive disorders.

This disease is rare and its clinical, EEG and radiological characterisation is not sufficiently established. The investigators will evaluate these three aspects for the anti-LGI1 cohort of patients of the National Reference Center of autoimmune encephalitis.

Inclusion Criteria:

• Age > 18 years
• Diagnosis of anti-LGI1 encephalitis based on sera or CSF samples in the National Reference Center of autoimmune encephalitis from 2011/06 to 2019 july 1st.
• Clinical follow-up in France

Exclusion Criteria:

• Anti-LGI1 antibody associated with another encephalitis antibody
• Foreign follow-up

Study Population Description : Adult patients presenting an anti-LGI1 autoimmune encephalitis, followed in France and diagnosed by sera or CSF samples at the National Reference Center of autoimmune encephalitis.