Nonparaneoplastic Anti-N-Methyl-d-Aspartate Receptor Encephalitis: A Case Series of Four Children

A rare, severe form of immune-mediated encephalitis recently has been described, associated with antibodies against N-methyl-d-aspartate receptors. It is reported mostly in women with ovarian tumors. Nonparaneoplastic presentations are less common. We describe four children with a neuropsychiatric and extrapyramidal syndrome associated with the presence of anti-N-methyl-d-aspartate receptor antibodies in cerebrospinal fluid and serum, without evidence of neoplasia. Three children recovered completely after immunomodulatory therapy, i.e., intravenous immunoglobulin and/or steroids, methylprednisolone, and/or adrenocorticotrophic hormone.