Anti-N-Methyl-D-Aspartate Receptor (NMDAR) Encephalitis in Children and Adolescents: A Systematic Review and Quantitative Analysis of Reported Cases.

Objective: This pooled analysis, from a systematic review, examines anti-N-Methyl D-Aspartate Receptor (NMDAR) encephalitis presentation in children and adolescents.

Method: A comprehensive literature search from database inception through December 31, 2019, using PubMed, PsycInfo, and OVID was performed. Case reports and case series were included. Sample characteristics are described. Prodromal and presenting symptoms between partial recovery and full recovery are compared. The association between presenting symptoms and abnormal MRI, abnormal EEG, and tumor presence are determined.

Results: The sample (n=283) had a mean age of 10.8 years with 75.3% females. The most common prodromal and presenting symptom was seizure (29.7% and 63.3%, respectively). Partial and full recovery did not differ for prodromal and presenting symptoms. Multivariate logistic regression analysis found that (1) delusion were significantly associated with higher odds and aggressive behavior was associated with lower odds for abnormal findings on magnetic resonance imaging (MRI); (2) waxing and waning of symptoms were significantly associated with higher odds for abnormal electroencephalograms (EEG), and (3) increased age and psychosis were each significantly associated with increased odds, and sleep disturbance and orofacial dyskinesia with lower odds for tumor presence.

Conclusion: Given the pattern of findings, routinely obtaining MRI and EEG should be considered for anti-NMDAR encephalitis in children and adolescents presenting with delusion and waxing and waning of symptoms, respectively. Investigation of tumors should be considered in patients with anti-NMDAR encephalitis especially when psychosis is present.