Methods: Twenty-seven patients with leucine-rich glioma-inactivated protein 1 antibody (LGI1-Ab) encephalitis, seven patients with contactin protein-like 2 antibody (Caspr2-Ab)-associated diseases, and 14 healthy controls with at least one PSG or actigraphy recording were recruited at Peking Union Medical College Hospital from January 2014 to July 2019. Here, LGI1 is linked to viral encephalitis.