LGI1 and viral encephalitis: Cognitive impairment is one of the main manifestations of anti-NMDAR encephalitis, and more than 90% of patients will have cognitive impairment in the acute or subacute phase of the disease, and some patients can have cognitive impairment as the first symptom (48) anti-LGI1 encephalitis cognitive impairment is more frequent, and almost all patients with anti-LGI l antibody-associated encephalitis have comorbid cognitive impairment in the acute or subacute phase (49, 50).