Epstein-Barr virus encephalitis with excessive daytime sleepiness as the main manifestation: Two case reports

Rationale: Excessive daytime sleepiness (EDS) is a clinical manifestation of various disorders. Here, we report 2 cases of EDS related to Epstein-Barr virus (EBV) encephalitis. Patient concerns: Both the patients were elderly men. Case 1 presented with EDS with headache and fever. Case 2 was presented with EDS only. The 2 patients slept normally at night without taking sleeping pill. They were able to get up and go to the toilet and eat by themselves during the day, but they almost slept at other times. Diagnosis: After admission, a lumbar puncture was performed to collect the cerebrospinal fluid, and next-generation sequencing showed that EBV infection was detected. Combined with the patient's head magnetic resonance imaging and clinical features, a diagnosis of EBV encephalitis was made. Interventions: Both patients received antiviral therapy. Outcomes: Case 1 had a rapid improvement in headache and fever and was discharged from the hospital after the symptoms of EDS gradually improved. In case 2, EDS symptoms gradually improved. Two patients were followed up for 3 months after discharge, and the outcome was good. Lessons: EDS can also be the main clinical manifestation of viral encephalitis, and we should diagnose and identify it early and treat it promptly.