[Neuroradiological findings in the acute stage of influenza encephalopathy]

Area of Science:

• Neurology
• Pediatrics
• Radiology

Background:

• Influenza encephalopathy (IE) significantly impacts Japanese children aged 1-5 years.
• IE presents with high mortality (15-30%) and morbidity (25-40%).
• Early diagnosis and prognosis prediction are crucial for managing IE.

Purpose of the Study:

• To propose a neuroradiological classification of Influenza Encephalopathy (IE).
• To differentiate four distinct types of IE based on imaging findings.
• To correlate specific radiological features with prognosis in pediatric IE.

Main Methods:

• Analysis of neuroradiological findings in pediatric patients with Influenza Encephalopathy (IE).
• Classification of IE into four proposed types: acute necrotising encephalopathy (ANE), hemorrhagic shock and encephalopathy syndrome (HSES), acute brain swelling (ABS), and acute encephalopathy with febrile convulsive status epilepticus (AEFCSE).
• Description of characteristic radiological features for each IE type in the early disease phase.

Main Results:

• Four neuroradiological types of IE were identified: ANE (thalamic lesions), HSES (diffuse cerebral edema), ABS (reversible cerebral swelling), and AEFCSE (lobar edema).
• Specific imaging findings like thalamic lesions, cytotoxic edema, and lobar edema are associated with different IE types.
• Lobar edema in AEFCSE develops later, correlating with seizures and neurological decline.

Conclusions:

• Influenza encephalopathy (IE) is a complex condition encompassing diverse encephalopathic types.
• Neuroradiological classification offers a framework for understanding IE prognosis.
• Further research is essential to fully elucidate the spectrum of IE and improve patient outcomes.