Acute necrotizing encephalopathy of childhood represents a novel entity of acute 
encephalophathy, predominantly affecting infants and young children living in 
Taiwan and Japan. It manifests with symptoms of coma, convulsions, and 
hyperpyrexia after 2 to 4 days of respiratory tract infections in previously 
healthy children. The hallmark of acute necrotizing encephalopathy of childhood 
consists of multifocal and symmetric brain lesions affecting the bilateral 
thalami, brainstem tegmentum, cerebral periventricular white matter, or 
cerebellar medulla. The etiology and pathogenesis of this kind of acute 
encephalopathy remain unknown, and there is no specific therapy or prevention. 
The prognosis is usually poor, and less than 10% of patients recover completely. 
We report a 3-year-old previously healthy girl presenting with acute necrotizing 
encephalopathy of childhood associated with influenza type B virus infection, 
which resulted in severe neurologic sequelae. We also review the current 
knowledge of the clinical, neuroimaging, and pathologic aspects of acute 
necrotizing encephalopathy of childhood.