Clinical outcome of acute necrotizing encephalopathy in related to involving the brain stem of single institution in Korea

Abstract

Purpose: Acute necrotizing encephalopathy (ANE) is a fulminant disease of the brain characterized bybilateral thalamic lesions, and is prevalent among children in East Asia. The prognosis of ANE is usuallypoor with a high mortality rate and neurological sequelae. This study aimed to delineate the clinicalcharacteristics and prognostic factors of ANE. Methods: We retrospectively analyzed clinical data of 399 pediatric patients with encephalitis who wereadmitted to Samsung Medical Center from December 1998 to March 2011. We enrolled ten patients (11cases) with ANE and analyzed their demographic, clinical, and neuroimaging data. The location and extent ofthe brain regions were checked based on fluid-attenuated inversion recovery, T1-, and T2-weighted imagingfindings; the presence of contrast enhancement, restricted diffusion, and hemorrhage. Results: Ten patients were identified, including one patient with two episodes. The median age ofonset was 1.5 years (0.4–8.4 years). The mortality rate was 40%, and only 30% of patients survivedwithout neurological sequelae. The definite involvement of the brainstem on brain magnetic resonanceimaging was significantly correlated with mortality (P =0.04). Conclusion: Broad and extensive brainstem involvement suggested the fulminant course of ANE. Earlydiagnosis of ANE before brainstem involvement, through careful identification of symptoms of braindysfunction, may be the best way to achieve better neurological outcomes.