Children, Influenza, Encephalopathy, Clinical Characteristics, Laboratory Index

Background: To explore the early clinical features and laboratory findings of influenza-associated acute necrotizing encephalopathy (IANE). Methods: The demographics data, clinical manifestations, and laboratory indicators of cases diagnosed with IANE and influenza with febrile convulsions (FS), respectively, admitted to Guangzhou Women and Children’s Medical Center from January 2016 to January 2020 were retrospectively analyzed. Results: Among the 25 cases of IANE, there were 9 males and 16 females, aged 3 to 6 years. The mortality rate was 40.00% (10/25). Influenza virus type A in 9 cases (36.00%) and influenza virus type B in 10 cases (40.00%). The main clinical manifestations of children with IANE were acute disorders of consciousness (64.00%, 16/25) and convulsions (72.00%, 18/25), which were statistically significant when compared with the FS group (P < 0.05). Typical changes on cranial MRI of IANE were cerebral edema, typically with symmetric necrosis of the thalamus and other brain structures. Significant differences (P < 0.05) existed between the IANE and FS groups in laboratory indicators for ALT, AST, CK-MB, LDH, cerebrospinal fluid (CSF) microprotein, CSF LDH, which were above the normal reference range. In addition, logistic regression analysis showed that LDH ≥ 348.5 U/L predicted a significantly higher risk of IANE. Conclusions: Children with influenza present early with acute impairment of consciousness or convulsive seizures, or with elevated AST, ALT, CK-MB, LDH, and CSF protein and CSF LDH, especially if blood LDH is ≥348.5 U/L, should be closely evaluated and alerted to the possibility of IANE.