Elsevier

Pediatric Neurology

Volume 50, Issue 2, February 2014, Pages 181-184
Pediatric Neurology

Clinical Observations
Anti–N-methyl-D-aspartate Receptor-Mediated Encephalitis in Infants and Toddlers: Case Report and Review of the Literature

https://doi.org/10.1016/j.pediatrneurol.2013.10.002Get rights and content

Abstract

Background

Anti-N-methyl-D-aspartate receptor encephalitis is an increasingly well-recognized inflammatory encephalitis in children and adults.

Patient

We report a previously healthy 21-month-old girl who presented with behavioral change, self-mutilatory behavior, and echolalia. Over the ensuing weeks, symptoms progressed to include unilateral upper extremity dystonia, gait impairment, dysphagia, and mutism. Magnetic resonance imaging of the brain showed a tiny area of signal abnormality in the subcortical white matter, but was otherwise normal. Continuous video electroencephalography showed slowing of the background rhythm, but was without epileptiform discharges. Lumbar puncture showed a mild pleocytosis of mixed cellularity; bacterial culture and testing for various viral encephalitides were negative. Serum and cerebrospinal fluid was positive for autoantibodies directed against the N-methyl-D-aspartate receptor, and she was diagnosed with anti–N-methyl-D-aspartate receptor encephalitis. The patient was successfully treated with a regimen of immunotherapy that included dexamethasone, intravenous immunoglobulin, and rituximab. One year after initial presentation, the patient remained symptom-free. We further review the clinical characteristics, results of diagnostic studies, treatment, and outcome of infants and toddlers diagnosed with anti–N-methyl-D-aspartate receptor encephalitis that have been previously reported in the literature.

Conclusion

Anti–N-methyl-D-aspartate receptor encephalitis is relatively common among infants and toddlers and often presents with a pattern of defining characteristics in this age group, particularly the absence of associated tumor.

Introduction

Encephalitis mediated by autoantibodies directed against the N-methyl-D-aspartate receptor (anti-NMDA receptor encephalitis) is a now well-described clinical entity in children and adults1, 2, 3, 4 and constitutes one of the most common causes of encephalitis in children.5 The syndrome is notable both for its often dramatic clinical presentation and for its typically favorable response to therapy. The syndrome of anti-NMDA receptor encephalitis includes some combination of neuropsychiatric symptoms, movement disorder, seizures, and/or autonomic dysfunction or vital sign instability, potentially progressing to coma and, in rare cases, death.2, 3, 4 In children, symptoms of abnormal behavior, speech disturbance, seizures (including status epilepticus6), and movement disorder seem to predominate.1, 7

Approximately 40% of all reported patients with anti-NMDA receptor encephalitis are children (i.e., age <18 years);4 a recent study compiling more than 577 patients with anti-NMDA receptor encephalitis found that 37% of them occurred in the pediatric age group.7 However, few infants (<12 months) and toddlers (≥12 months and <36 month) had been reported previously.2, 3, 8, 9, 10

We describe a 21-month-old girl with anti-NMDA receptor encephalitis treated with first- and second-line immunotherapy who had recovered completely after a year. We also review the cases of anti-NMDA receptor encephalitis in infants and toddlers that have been published previously in the literature.

Section snippets

Case Report

The patient was a previously healthy, developmentally normal 21-month-old girl. She had received the 2011-2012 influenza vaccine, H1N1 vaccine, and immunization for hepatitis A approximately 2 weeks before presentation. Initial symptoms included unusual “temper tantrums,” self-mutilatory behavior, and echolalia/echopraxia. She was evaluated by her primary care provider who began treatment for acute otitis media with amoxicillin.

Days later, she seemed to be using her left hand less than usual;

Discussion

Anti-NMDA receptor encephalitis is an increasingly recognized neurological syndrome in children and adults. However, there are few reports in the literature of cases involving infants and toddlers (Table).2, 3, 8, 9, 10, 13 We present an illustrative case of a 21-month-old female toddler with anti-NMDA receptor encephalitis who exhibited a complete response to second-line immunotherapy.

Florance et al.2 reported the first case series of pediatric patients (age <18 years) with anti-NMDA receptor

References (17)

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