Coronavirus disease 2019-associated acute necrotizing encephalopathy in a 9-year-old boy

Coronavirus disease 2019 (COVID-19) is associated with a variety of neurologic manifestations. Acute necrotizing encephalopathy (ANE) is a rare, life-threatening complication characterized by rapid deterioration of neurologic status following viral infection, such as influenza or human herpesvirus 6. Since the COVID-19 pandemic, a rise in ANE cases associated with the infectious disease has been reported in adult patients. We present a case of COVID-19-associated ANE in a 9-year-old boy. The patient experienced 3 days of fever and mild respiratory symptoms, followed by lethargy. Magnetic resonance imaging on day 4 showed hyperintensity in the bilateral thalami, midbrain, pons, hypothalamus, and cerebellum, along with some areas of hemorrhage. From the imaging findings, ANE was strongly suspected, leading to the initiation treatment involving a 5-day course of remdesivir and multiple immunomodulator therapies, including high-dose corticosteroids, intravenous immunoglobulin, tocilizumab, and 10 cycles of therapeutic plasma exchange. Subsequently, the patient gradually improved, experiencing only minor neurological sequelae and showing favorable radiologic improvement. In COVID-19-infected patients presenting neurologic symptoms, it is crucial to promptly suspect and investigate unexplained encephalopathy using neuroimaging. Early administration of immunomodulator therapy is vital for the diagnosis and optimizing clinical outcomes.