Abstract: Objective: To analyze the clinical characteristics of one child with acute necrotizing encephalopathy(ANE) with good prognosis, and to improve the clinicians' understandings of the disease. Methods: The clinical materials of a patient with ANE were collected, and the clinical features and diagnosis and treatment experience were retrospectively analyzed combined with the relative literatures. Results: The previously healthy boy,aged 3 years old,was admitted to the hospital due to pneumonia and his condition was improved after anti-infection treatment. On the 4th day, the patient had a high fever again;on the 10th day, the patient suddenly became generalized convulsive seizures, then the patient was in coma. The brain magnetic resonance imaging (MRI) revealed the multiple and symmetric necrosis in the bilateral thalami, brainstem and other areas. The patient was diagnosed as ANE and systemic inflammatory response syndrome (SIRS) and was treated with anti-infection, intravenous high-dose methylprednisolone, intravenous immunoglobulin and symptomatic treatment. After regular outpatient follow-up of 3 months,both Gesell Development and Development of Social Skills assessment of the patient improved to the marginal defect level;the patient was expected to achieve self-care and was still in rehabilitation treatment. Conclusion: The early clinical manifestations of ANE patients are lack of specificity, often accompaning high fever, rapid disease progression and critical condition;the diagnosis of ANE is mainly based on brain MRI findings;early and timely immunomodulatory therapy is effective and can improve the the prognosis of the patients with ANE.

Key words: acute necrotizing encephalopathy, bilateral thalamus necrosis, immunomodulatory therapy, case report