ABSTRACT
Herpes simplex virus encephalitis (HSE) is a common form of viral encephalitis, often with a single-phase course. A case of HSE with abnormal mental behavior as the main manifestation, admitted in Peking University Shenzhen Hospital in Octorber 2020, which improved after sufficient antiviral treatment was reported. After 2 months, abnormal mental behavior with memory deterioration recurred. It was considered as anti-N-methyl-D-aspartate receptor antibody combined with anti-glutamic decarboxylase antibody double-positive encephalitis, and improved after rituximab treatment. At present, there is no clinical report of such double antibody positive autoimmune encephalitis secondary to HSE. The purpose of this case report is to raise clinician awareness of post-HSE autoimmune encephalitis.