Background: Acute necrotizing encephalopathy of childhood (ANEC) is a rare but distinctive type of encephalopathy predominantly involving infants and young children. This case report describes the characteristic neuroimaging findings which can aid in early diagnosis of ANEC. Case Presentation: An 11-year-old boy presented with a 2-day history of fever and flu-like illness and was given symptomatic treatment. He subsequently deteriorated on day 3 of illness with generalized tonic-clonic seizure and impaired consciousness. Magnetic resonance imaging done revealed abnormal signal intensities at bilateral thalami, brainstem, and cerebellum, which are suggestive of ANEC, correlating with his clinical presentation. Treatment was started immediately, but the patient had a very poor recovery. Conclusion: ANEC is a very rare encephalopathy and has very high mortality and morbidity with severe neurologic sequelae. Early diagnosis is important so that appropriate management can be provided.

Keywords: Case report, acute necrotizing encephalopathy of childhood (ANEC), influenza A, H1N1.