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.
Ghosh S, Basu A. Acute encephalitis syndrome in India: the changing scenario. Ann Neurosci 2016;23(3):131–133. DOI: 10.1159/00044 9177.
John TJ, Verghese VP, Arunkumar G, et al. The syndrome of acute encephalitis in children in India: need for new thinking. Indian J Med Res 2017;146(2):158–161. DOI: 10.4103/ijmr.IJMR_1497_16.
Karmarkar SA, Aneja S, Khare S, et al. A study of acute febrile encephalopathy with special reference to viral etiology. Indian J Pediatr 2008;75(8):801–805. DOI: 10.1007/s12098-008-0150-2.
Tandel K, Sharma S, Dash PK, et al. Emergence of human West Nile Virus infection among pediatric population in Madhya Pradesh, India. J Med Virol 2019;91(3):493–497. DOI: 10.1002/jmv.25325.
Tiwari JK, Malhotra B, Chauhan A, et al. Aetiological study of viruses causing acute encephalitis syndrome in North West India. Indian J Med Microbiol 2017;35(4):529–534. DOI: 10.4103/ijmm.IJMM_17_180.
Jain P, Prakash S, Tripathi PK, et al. Emergence of Orientia tsutsugamushi as an important cause of acute encephalitis syndrome in India. PLoS Negl Trop Dis 2018;12(3):e0006346. DOI: 10.1371/journal.pntd.0006346.
Kumar R, Kumar P, Singh MK, et al. Epidemiologicalprofile of acute viral encephalitis. Indian J Pediatr 2018;85(5):358–363. DOI: 10.1007/s12098-017-2481-3.
Bloch KC, Glaser CA. Encephalitis surveillance through the emerging infections program, 1997–2010. Emerg Infect Dis 2015;21(9):1562–1567. DOI: 10.3201/eid2109.150295.
Simon DW, Da Silva YS, Zuccoli G, et al. Acute encephalitis. Crit Care Clin 2013;29(2):259–277. DOI: 10.1016/j.ccc.2013.01.001.
Kneen R, Michael BD, Menson E, et al. Management of suspected viral encephalitis in children - association of British neurologists and British pediatric allergy immunology and infection group national guidelines. J Infect 2012;64(5):449–477. DOI: 10.1016/j.jinf.2011.11.013.
Ravi V, Mani R, Govekar S, et al. Aetiology and laboratory diagnosis of acute encephalitis syndrome with special reference to India. J Commun Dis 2014;46(1):12–23.
Sharma S, Mishra D, Aneja S, et al. Consensus guidelines on evaluation and management of suspected acute viral encephalitis in children in India. Indian Pediatr 2012;49(11):897–910. DOI: 10.1007/s13312-012-0216-0.
Marais S, Thwaites G, Schoeman JF, et al. Tuberculous meningitis: a uniform case definition for use in clinical research. Lancet Infect Dis 2010;10(11):803–812. DOI: 10.1016/S1473-3099(10)70138-9.
Murthy JM. Tuberculous meningitis: the challenges. Neurol India 2010;58(5):716–722. DOI: 10.4103/0028-3886.72178.
Mizuguchi M, Abe J, Mikkaichi K, et al. Acute necrotising encephalopathy of childhood: a new syndrome presenting with multifocal, symmetric brain lesions. J Neurol Neurosurg Psychiatry 1995;58(5):555–561. DOI: 10.1136/jnnp.58.5.555.
Okumura A, Mizuguchi M, Kidokoro H, et al. Outcome of acute necrotizing encephalopathy in relation to treatment with corticosteroids and gammaglobulin. Brain Dev 2009;31(3):221–227. DOI: 10.1016/j.braindev.2008.03.005.
Wong AM, Simon EM, Zimmerman RA, et al. Acute necrotizing encephalopathy of childhood: correlation of MR findings and clinical outcome. Am J Neuroradiol 2006;27(9):1919–1923.
Pohl D, Alper G, Van Haren K, et al. Acute disseminated encephalomyelitis updates on an inflammatory CNS syndrome. Neurology 2016;87(9 Suppl 2):S38–S45. DOI: 10.1212/WNL.0000000000002825.
Graus F, Titulaer MJ, Balu R, et al. A clinical approach to diagnosis of autoimmune encephalitis. Lancet Neurol 2016;15(4):391–404. DOI: 10.1016/S1474-4422(15)00401-9.
Dalmau J, Lancaster E, Martinez-Hernandez E, et al. Clinical experience and laboratory investigations in patients with anti-NMDAR encephalitis. Lancet Neurol 2011;10(1):63–74. DOI: 10.1016/S1474-4422(10)70253-2.
Payer J, Petrovic T, Lisy L, et al. Hashimoto encephalopathy: a rare intricate syndrome. Int J Endocrinol Metab 2012;10(2):506–514. DOI: 10.5812/ijem.4174.
Odaka M, Yuki N, Yamada M, et al. Bickerstaff's brainstem encephalitis: clinical features of 62 cases and a subgroup associated with Guillain-Barré syndrome. Brain 2003;126(Pt 10):2279–2290. DOI: 10.1093/brain/awg233.
Gaspard N, Hirsch LJ, Sculier C, et al. New-onset refractory status epilepticus (NORSE) and febrile infection-related epilepsy syndrome (FIRES): State of the art and perspectives. Epilepsia 2018;59(4):745–752. DOI: 10.1111/epi.14022.
Takanashi J. Two newly proposed infectious encephalitis/encephalopathy syndromes. Brain Dev 2009;31(7):521–528. DOI: 10.1016/j.braindev.2009.02.012.
Fukui KO, Kubota M, Terashima H, et al. Early administration of vitamins B1 and B6 and l-carnitine prevents a second attack of acute encephalopathy with biphasic seizures and late reduced diffusion: a case control study. Brain Dev 2019;41(7):618–624. DOI: 10.1016/j.braindev.2019.02.015.
Christopher R, Bindu PS. An insight into the biochemistry of inborn errors of metabolism for a clinical neurologist. Ann Indian Acad Neurol 2008;11(2):68–81. DOI: 10.4103/0972-2327.41873.
Bosilkovski M. Brucellosis: Clinical manifestations, diagnosis, treatment and prevention 2019, accessed August 18, 2019, available from https://www.uptodate.com.
Rathi N, Kulkarni A, Yewale V, et al. IAP guidelines on rickettsial diseases in children. Indian Pediatrics 2017;54(3):223–229. DOI: 10.1007/s13312-017-1035-0.
Centers for Disease Control and Prevention (CDC). Naegleria fowleri—primary amebic meningoencephalitis (PAM). Available at: www.cdc.gov/parasites/naegleria/treament.html, accessed Sept 6, 2019.
Centers for Disease Control and Prevention (CDC). Acantamoeba—granulomatous amoebic encephalitis (GAE). Available at: www.cdc.gov/parasites/acanthamoeba/treatment.html, accessed Sept 6, 2019.
Jain S, Patel B, Bhatt GC. Enteroviral encephalitis in children: clinical features, pathophysiology, and treatment advances. Pathog Glob Health 2014;108(5):216–222. DOI: 10.1179/2047773214Y.000000 0145.
Kumar R, Basu A, Sinha S, et al. Role of oral minocycline in acute encephalitis syndrome in India - a randomized controlled trial. BMC Infect Dis 2016;16:67. DOI: 10.1186/s12879-016-1385-6.
Revised National Tuberculosis Control Programme and Indian Academy of Pediatrics. RNTCP updated pediatric TB guidelines 2019. Available at https://tbcindia.gov.in, accessed Sept 4, 2019.