Update on anti-N-methyl-D-aspartate receptor encephalitis in children and adolescents

Purpose of review Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a recently identified disorder that is increasingly recognized in children and adolescents. Prompt diagnosis and treatment are important to obtain full recovery. We review here the main clinical features and differential diagnosis and provide algorithms of the clinical correlates of antibody-mediated decrease of NMDAR and a suggested treatment approach. Recent findings The sharp increase of patients identified with anti-NMDAR encephalitis reveals a multistage disorder that usually presents with psychiatric manifestations progressing to a decrease of verbal output, catatonia, seizures, dyskinesias, and frequent autonomic instability and hypoventilation. In adults, the disorder often occurs in association with a tumor that expresses NMDAR (usually ovarian teratoma), but in male patients and children the presence of a tumor is rare. Given that patients' antibodies have pathogenic effects on the NMDAR, immunotherapy and tumor resection, when appropriate, are often effective. The outcome is usually good, but the recovery is slow with frequent protracted symptoms of frontal lobe dysfunction. Summary Anti-NMDAR encephalitis is a severe but treatable disorder that frequently affects children and adolescents and is likely under-recognized. The syndrome is highly predictable, recognizable on clinical grounds and can be confirmed with the demonstration of NMDAR antibodies.