Introduction:

Anti-N-methyl-d-aspartate receptor (Anti-NMDAR) encephalitis is one of the commonest forms of autoimmune encephalitis and is emerging as a leading cause of acute to subacute encephalitis syndrome.

Methods: Clinical profile and outcome of children aged upto14 years with anti NMDAR encephalitis(by CSF anti NMDA receptor antibody positivity) between January 2013 and June 2018 in a north Indian tertiary care center were retrospectively reviewed.

Results: Out of 153 children with acute/subacute encephalitis syndrome, NMDA encephalitis was suspected in64 children (41%).  Of them, 19% children (n=30, 17 girls, median age 7 years, IQR 5-10 years) hadproven Anti-NMDAR encephalitis. Commonest clinical manifestations were neuropsychiatric (96%), extrapyramidal (86%), seizures(86 %%) and autonomic disturbances (60 %).

Sites affected predominantly on MRI brain were limbic region (13 %) and temporal lobe(10 %) whereascommonest EEG abnormality was generalized slowing (95%).

In the initial episode, 27 (90%) childrenresponded to concomitant IVIG and methyl prednisolone pulse therapy followed by oral steroid with tapering over 8 -12 weeks. However 3 children additionally required plasmapharesis, of which 2 also received rituximab. Seven (23%) had recurrences over (14 months, IQR 6-20 months), of which 5 responded favourably to IVIG and methylprednislone therapy, remaining 2 required plasmapheresis (1 required rituximabas well).None of the patients were positive on tumor screen.

Conclusion: Timely identification and early institution of immunotherapy is imperative for favorable long term outcome in children with suspected Anti NMDAR encephalitis.