Objective: We assessed the neurologic manifestation of influenza among hospitalized children with influenza (neuro-flu), comparing their demographic and clinical characteristics to hospitalized children without neurologic manifestation (classic-flu).

Methods: A retrospective, cohort study. All children with laboratory confirmed influenza (PCR), admitted to the Soroka University Medical Center (SUMC) between 2016 and 2019 were included.

Results: Overall, 951 patients were identified: 201 with neuro-flu, and 750 with classic-flu. Seizures (n = 125) were the most common neurological manifestation of neuro-flu (seizure-flu): 73 simple febrile seizures, 45 atypical febrile seizures, and 7 afebrile seizures. Neurological comorbidities rates were significantly higher in neuro-flu versus classic-flu (13.0% vs. 6.0%), while respiratory and cardiac comorbidities were less common in neuro-flu (4.5% and 0.5% vs. 8.0% and 4.5%, respectively). Neuro-flu (compared with classic-flu) was associated with leukocytosis (21.0% vs. 13.0%, P < 0.001) and lower C-reactive protein (CRP) levels (2.4 ± 4.1 vs. 3.3 ± 5.4, P = 0.03). Notably, patients with classic flu had a more prominent respiratory disease, as they had more chest radiographs (CXR) performed (60.5% vs. 45.0%, P < 0.001), higher rates of pneumonia (27.0% vs. 12.0%, P < 0.001), and antibiotic (antibacterial) treatment (60.0% vs. 42.0%, P < 0.001).

Conclusions: Influenza can appear as a neurologic disease, manifested mainly with febrile seizures. Children with neuro-flu have more neurologic comorbidities, suggesting that neuro-flu is mainly driven by host-factors, rather than by pathogen-factors. The relatively lower rates of pneumonia in neuro-flu suggests that these patients are admitted in the early stage of the influenza infection, which triggers the neurologic response.