Published online by Cambridge University Press: 24 June 2022
Background: Acute Necrotizing Encephalopathy (ANEC) is a rare neuroinflammatory disorder involving the deep grey matter following viral infection and has been associated with the RANBP2 gene. We aimed to evaluate clinical and imaging features in ANEC patients. Methods: This retrospective chart review of ANEC patients (2012-2020) seen at a tertiary pediatric center included analysis of outcomes including ANE-Severity Score, Expanded Disability Status Scale (EDSS) and the modified Rankin Scale (mRS), semi-quantitative imaging scores (degree of swelling or hemorrhage rated 0 (none)-5 (severe/massive)), and dichotomous outcomes including RANBP2 gene status, influenza status. Results: 20 patients were included (Avg. age at presentation 3.5 yrs IQR=3.56., F:M 2.33:1). 3/20 experienced recurrences. All patients with recurrences were positive for RANBP2 mutations. 10/20 patients were influenza positive. 7/20 were RANBP2 mutation positive. We observed higher likelihood of hemorrhage in influenza-positive compared to negative patients (W=78, p=0.048). Kaplan-Meier survival curve analysis revealed that patients without brainstem lesions were more likely to reach minimal/no disability (EDSS<=2) than patients with brainstem lesions (p=0.035). Conclusions: Hemorrhage is more likely to be seen in children with ANEC who are positive for influenza. RANBP2 status was predictive of relapse but not predictive of overall outcome.