Purpose: Acute encephalitis syndrome (AES) poses challenges to physicians owing to acute presentation, often rapid neurologic deterioration, myriad causes including noninfective inflammatory disorders of central nervous system (CNS) and low microbiologic yield. We broadly discuss common and less common causes of AES and their clinical, laboratory including radiologic features as specific diagnosis guides management and improves outcome. Materials and methods: Literature search was performed using keywords "Paediatric acute encephalitis" in MEDLINE database from 2009 to 2019 and all relevant articles (barring case reports) in English language were reviewed. Landmark articles prior to 2009 were also reviewed.
Conclusion:Acute encephalitis remains a diagnostic and therapeutic challenge in neurocritical care. The recognition of etiological agent and encephalitis mimics by investigations is important for specific therapeutic measures. Judicious use of neuroimaging, cerebrospinal fluid (CSF) analysis and appropriate lab tests helps in diagnosing specific entities especially noninfective mimics of AES which has important treatment and prognostic implication. Initial stabilization and institution of supportive measures remains key to successful management.