Clinical profile and predictors of outcome in children admitted to PICU with acute encephalitis syndrome

Ekambaranath Sambasivam, Jayakumar Muthaiyan, Sreedivya Mohan, Aravind Malayappan Ayyavoo, Ganesh Jayachandran


Background: Acute encephalitis syndrome (AES) is defined as the acute onset of fever and change in mental status (including symptoms such as confusion, disorientation, coma or inability to talk) and/or new onset seizures (excluding febrile seizures) in a person of any age at any time of the year. AES is reported mainly from Assam, Bihar, Tamil Nadu, Karnataka, Uttar Pradesh contributing approximately to 80% cases with case fatality rate of 20-25%. In view of paucity of clinical studies from Tamil Nadu, this study was undertaken to have a better insight on the clinical profile and prognostic indicators of AES in children. Objective of present work was to study the clinical profile and predictors of outcome of Acute encephalitis syndrome patients admitted in PICU

Methods: This retrospective study was conducted in children with AES admitted to PICU, Stanley medical college over a period of 1year (May 2015-May 2016). 30 cases were studied. Clinical features, demography, immunisation status, and outcome were recorded. Results of blood investigations, peripheral smear, neuroimaging, CSF analysis and IgM ELISA for HSV, JE, CMV, Dengue were recorded and analysed.

Results: Mean age of cases was 3.5±3.3years. Male to female ratio was 1.1:1. Etiology included HSV (6.67%), malaria (3.33%), dengue (3.33%), tubercular meningitis (3.33%), AES of unknown origin (83.3%) 11, Most common presentation was seizures 21 (70%). 17 (56.6%)presented with GCS <8. 11 (36.6%) required inotrope support, 16 (53.4%) were ventilated. Laboratorial findings included, leukocytosis in 17 (66.7%), dysglycemia in 12 children (39.99%), hyponatremia in 10 (33.33%), hypernatremia in 8 (26.67%) Mortality was observed in 11 cases (36.67%). Hyponatremia (p=0.02) and cases requiring ionotrope support on admission (p=0.0003) were significantly associated with mortality.

Conclusions: There was no case of Japanese encephalitis. Hyponatremia being significantly associated with mortality among children with AES, warrants detailed evaluation to define the etiology which will aid in appropriate management. Maintaining euvolemia, prompt identification of shock and appropriate use of inotropes is of utmost importance. Varied and changing etiologies of AES poses a diagnostic challenge. 


Acute encephalitis syndrome, Hyponatremia, Outcome, Seizures

Full Text:



Joshi R, Kalantri SP, Reingold A, Colford JM Jr. Changing landscape of acute encephalitis syndrome in India: a systematic review. Natl Med J India. 2012;25:212-20.

Saminathan M, Karuppanasamy K, Pavulraj S, Gopalakrishnan A, Rai RB. Acute encephalitis syndrome-A complex zoonotic disease. Int J Livestock Res. 2013;3(2):174.2013;78.

Francisco de Assis Aquino Gondim et al Medscape. Neurology Viral Encephalitis." drugs & diseases>"

Ghosh S, Basu A. Acute encephalitis syndrome in india: the changing scenario. Ann Neurosci. 2016;23(3):131-3.

Jain P, Jain A, Kumar A, Prakash S, Khan DN, Singh KP et al. Epidemiology and etiology of acute encephalitis syndrome in North India. Jpn J Infect Dis. 2014;67(3):197-203.

Kelly R. Acute Encephalitis syndrome outbreaks in India–an ongoing puzzle. School of Public Health and Community Medicine. 2014.

Themistocleous MS, Antoniades E, Giakoumettis D, Kalyvas AV, Mitsios A, Sfakianos G. Herpes simplex virus Type 1 encephalitis in an adolescent presenting with acute hydrocephalus. J Surg Case Rep. 2017;2017(2).

Kawano G, Iwata O, Iwata S, Kawano K, Obu K, Kuki I et al. Determinants of outcomes following acute child encephalopathy and encephalitis: pivotal effect of early and delayed cooling. Arch Dis Child. 2011;96(10):936-41.

Singh GK, Singh CM, Ranjan A, Agarwal N, Pandey S, Kumar P et al. Determinants of Acute Encephalitis Syndrome (AES) in Muzaffarpur district of Bihar, India: A case–control study. Clinical Epidemiology and Global Health. 2016;4(4):181-7.

Bhaswati B, Chakraborty D, Ghosh S, Mishra R, Rahman M, Bhattacharya N et al. Epidemiological Investigation of an Outbreak of Acute Encephalitis Syndrome (AES) in Malda District of West Bengal, India. Clinical Microbiology. 2015;181(4).

Misra UK, Kalita J, Singh RK, Bhoi SK. A study of hyponatremia in acute encephalitis syndrome: a prospective study from a tertiary care center in India. Journal of Intensive Care Medicine. 2017 Jan 1:0885066617701422.

Dowell E. Encephalitis Society fact sheet. Available from:

Solomon T, Thao TT, Lewthwaite P, Ooi MH, Kneen R, Dung NM et al. A cohort study to assess the new WHO Japanese encephalitis surveillance standards. Bulletin of the World Health Organization. 2008;86(3):178-86.

Jain A, Jain P, Jain B. Unveiling the Undiscovered: Etiology of Acute Encephalitis Syndrome in North India. J Neuroinfect Diseases. 2015;6(2).

Thapa LJ, Twayana RS, Shilpakar R, Ghimire MR, Shrestha A, Sapkota S et al. Clinical profile and outcome of acute encephalitis syndrome (AES) patients treated in College of Medical Sciences-Teaching Hospital. J College Med Sci-Nepal. 2013;9(2):31-7.