Acute necrotising encephalopathy of childhood – A narrative review

Abstract

Acute encephalitis syndrome (AES) can pose challenges in diagnosis and management. Infection-associated acute encephalopathies (AEs) are increasingly being recognised and closely mimic AES. We provide an overview of various causes of AE and a detailed review of the clinical laboratory, including neuroradiologic features of acute necrotising encephalopathy (ANE) of childhood, its treatment, and outcome. A literature search was performed using the keywords’ Paediatric acute encephalopathy’ and ‘acute necrotising encephalopathy of childhood’ in PubMed and Google Scholar, and all relevant articles from 2001 to 2021 (including case reports) in the English language were reviewed. Relevant and major articles before 2001 were also reviewed. Infection-associated AEs remain under-recognised and pose a challenge in neurocritical care. Judicious use of neuroimaging and laboratory tests aids diagnosis of specific clinicoradiological AE syndromes. We need to suspect ANE if fever (esp. viral illness) is followed by the rapid deterioration in the sensorium associated with tone abnormalities or seizures. Neuroimaging typically shows symmetric lesions in the thalami, internal capsule or cerebellar white matter and tegmentum. While definite treatment guidelines are not available, several interventions have shown potential benefits in supporting patients with ANE. These include standard supportive care, immunotherapy, especially high-dose pulse methylprednisolone, therapeutic hypothermia initiated before 12 h to reduce cytokines, and anti-oedema measures. However, it is essential to note that outcomes in ANE can be highly variable, with a mortality rate of approximately 30% and only 10% experiencing intact survival. Predictors of poor outcome include age younger than one year, increased cerebrospinal fluid protein/transaminases, the presence of haemorrhage/cavitation/brainstem lesions on neuroimaging, and a high ANE severity score.