Abstract:Objective To summarize the clinical characteristics and pathogenesis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection-related encephalitis, aiming to provide new theoretical basis for clinical diagnosis and treatment. Methods Clinical characteristics as well as diagnosis and treatment process of 25 patients with SARS-CoV-2 infection-related encephalitis in the Second Affiliated Hospital of Shandong First Medical University were analyzed, and the pathogenesis was evaluated. Results The main prodromal symptoms were fever (80.0%), the initial symptoms were consciousness disturbance (56.0%), epileptic seizures (52.0%), and mental symptoms (36.0%). The subsequent symptoms were mainly autonomic nerve dysfunction (88.0%), epileptic seizures (68.0%), cognitive dysfunction (68.0%), motor impairment (64.0%), and language dysfunction (52.0%). The auxiliary examination results were mainly increase of content of cerebrospinal fluid (CSF) protein and increase of C-reactive protein (CRP); electroencephalogram (EEG) showed slowing down of a non-specific background rhythm, followed by abnormal discharges; the most common manifestation of magnetic resonance imaging (MRI) was abnormal high signal in the insular cortex and medial temporal lobe, followed by diffuse or focal microbleeds. The first-line treatment agents were glucocorticoid combined with immunotherapy, and the second-line treatment agent was monoclonal antibody. The prognosis was poor. Conclusion Patients with a history of exposure to SARS-CoV-2 infection, consciousness disturbance, epileptic seizures and mental symptoms should be vigilant to the possibility of encephalitis. CSF, EEG, and MRI auxiliary examination should be given. Once diagnosed, early intervention is necessary. The main pathogenesis include direct invasion, cytokine storm, excessive immune inflammation, specific lymphocyte response, etc.