Background: Acute necrotizing encephalopathy (ANE) of childhood has high mortality and neurological sequelae. The data on predictive factors is scarce.

Methods: Prospective cases from a tertiary care centre between 2014-2017. Demographic, clinical, biochemical, and radiological details, ANE-Severity Score (ANE-SS) and neuroimaging score (ANE Imaging Score-4) were evaluated. The outcomes were described using Glasgow Outcome Scale-extended (GOS-E). An 8-point neuroimaging score (ANE Imaging Score-8) was devised (Haemorrhage, cavitation, involvement of brain stem, cerebellar/cerebral white matter, internal/external capsule, hippocampus, stratum and tonsillar herniation) and predictive utility estimated.

Results: 35 children were included: male:female 15:20, age range 6-177 months and mean follow-up was 21 months (7-43 months). The etiology was identified in 8 cases (23%): dengue (5), influenza (H1N1) (1), Mycoplasma (1) and Herpes zoster (1). The mortality was 43% (15 of 35). Good outcome (GOS-E 1-4) was seen in 13 children, and poor outcome (GOS-E 5-8) in 22 children (63 %). The age ≥48 months (7/21 Vs 14/21; p=0.03) and ANE-SS of ≥5 (4/13 Vs 17/22; p=0.007) were statistically significant predictors of poor outcome. The gender and transaminases level did not predict outcome. The brain stem edema was higher in poor outcome group (10/16 Vs 2/9; p=0.058), though not statistically significant. The ANE-imaging score-4 (≥3)  and ANE imaging score-8 did not differ significantly between the outcome groups.

Conclusions: ANE has high mortality and neurological morbidity. The higher age (>48 months) and ANE-SS of ≥5 predicted poor outcome. Etiology remains unknown in 3/4^th of cases.