comparison of acute covid-19 encephalopathy with seasonal influenza a-associated encephalopathy

Objectives: to compare the clinical presentations and neurobiological features in children with acute coronavirus disease 2019 (covid-19) encephalopathy and seasonal influenza a virus (iav)-associated encephalopathy. methods: we conducted a retrospective cohort study on patients diagnosed with covid-19 encephalopathy between december 15, 2022, and january 15, 2023, and children diagnosed with iav-associated encephalopathy between november 2017 and march 2023, who were less than 18 years old at the children’s hospital, zhejiang university school of medicine. results: a total of 34 patients with acute covid-19 encephalopathy and 37 patients with iav-associated encephalopathy were included in this study. elevation of cerebrospinal fluid (csf) pleocytosis and csf glucose, as well as downregulation of monocyte and tnf-α, were observed in both the covid-19 icu group and the moderate severe group. the median age was younger (p < 0.001) and the median time for the occurrence of neurological symptoms was shorter (p < 0.001) in the covid-19 group compared with the iav group. more patients in the iav group had altered levels of consciousness (p < 0.001) and were admitted to the icu (p < 0.001). consequently, more severe cases were observed in the iav group (p = 0.007). brain imaging showed a predominance appearance of acute necrotizing encephalopathy in the iav group (p = 0.038). regarding blood parameters, leukomonocyte levels were lower in the iav group (p = 0.003) with lower expression of cd4 (p = 0.047). random blood glucose (p = 0.001), d dimer (p = 0.004), and cytokine il-2 (p = 0.005) were lower in the covid-19 group, while ifn-γ (p = 0.013) was significantly higher. conclusions: influenza a virus-associated encephalopathy presented more severe manifestations. however, ifn-γ may act as a protective cytokine in covid-19 encephalopathy.