N-methyl-D-aspartate-receptor Encephalitis: Case Series

Introduction: Anti-N-methyl-D-aspartate receptor encephalitis is a rare cause of encephalitis which was previously thought to be viral encephalitis. This rare illness may initially present as seizure episodes, psychiatric manifestations or an involuntary movement disorders which were observed in 8 different pediatric patients presented in this case series report.

Objectives: To present a case series of autoimmune encephalitis with different manifestations. To discuss the case management, prognosis and updates of this type of encephalitis.

Case Reports: We describe 8 cases of encephalitis presenting with different initial symptoms, 4 cases presented initially with psychiatric manifestations, 2 with movement disorder and 2 presented with seizure. Seven of the cases later develop seizure episodes at home. During hospital stay all of the patients manifested orofacial dyskinesias and choreoathetoid movements.

Discussions: Autoimmune conditions are not a common cause of encephalitis. However, it is imperative that a diagnosis of Autoimmune encephalitis be considered when other more common causes have been excluded or when there are certain diagnostic indicators such as presence of prodromal syndrome, orofacial dyskinesias, faciobranchial dystonic seizures, catatonia or extrapyramidal signs which were all seen in the 8 cases. Because of a strong clinical suspicion and following the course of the disease, the diagnosis of autoimmune encephalitis was highly considered. Treatment with Methylprednisolone is imperative once autoimmune encephalitis is entertained even in the absence of antibody titers or while awaiting for the result of autoimmune antibody screening. Six patients were started on Methylprednisolone with noted improvement 7 days after treatment, however two patient died due to hospital acquired infection, one patient went home against medical advice. Treatment with Steroids plus IVIG has been shown to improve outcome, however only three patient had IVIG treatment.

Conclusions: The diagnosis of anti-NMDAR encephalitis is challenging especially if the initial presentation can also present in other more common condition like CNS infection. A prompt diagnosis and early treatment with immunotherapy decreases mortality.

Keywords: autoimmune, encephalitis, N-methyl-D-aspartate, orofacial dyskinesia