Clinical Features, Therapeutic Response, and Follow-Up in Pediatric Anti-N-Methyl-D-Aspartate Receptor Encephalitis: Experience from a Tertiary Care University Hospital in India.

AIM: To describe the clinical features in pediatric anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis with specific reference to the spectrum of involuntary movements, and therapeutic response to pulsed intravenous methyl prednisolone.

METHOD: A total of 13 children with anti-NMDAR antibody positivity were evaluated.

RESULTS: Abnormal behavior, global regression, and seizures were universal. Movement disorder was characterized by hyperkinetic large amplitude, complex, multidirectional movements involving the limbs and orofacial musculature. Electroencephalogram was abnormal in all during the acute phase. All received intravenous methyl prednisolone. Plasmapheresis (n = 6) and intravenous immunoglobulin (n = 2) were administered due to subtherapeutic response during the acute illness. Monthly pulsed methyl prednisolone was administered to maintain remission. All improved substantially from the acute illness which was reflected in the modified Rankin score. Ten patients were followed up for a median duration of 10.30 ± 6.7 months. Residual symptoms included hypersomnolence, hyperphagia, hyperactivity, overfamiliarity, among others. Three had recurrence of partial syndrome that was related to delay in pulsed methyl prednisolone therapy. They improved and maintained improvement with reinitiation of pulsed methyl prednisolone therapy.

CONCLUSION: Anti-NMDAR encephalitis requires prolonged immunomodulatory therapy. Intravenous pulsed methyl prednisolone therapy is beneficial in inducing and maintaining remission. It is safe, effective, and well tolerated by children with anti-NMDAR encephalitis. The duration of treatment required for sustained remission and cure needs to be determined in long-term studies.