Adolescents and Young Adults With Anti-N-methyl-D-aspartate Receptor Encephalitis With Excited Catatonia: Literature Review and 2 Illustrative Cases.

Background: Catatonia is a complex neuropsychiatric syndrome that can be associated with several underlying etiologies including primary psychiatric and autoimmune disorders. Anti-N-methyl-D-aspartate receptor encephalitis is an autoimmune disorder typically characterized by seizures, movement abnormalities, and behavioral changes. Anti-N-methyl-D-aspartate can present with complex neuropsychiatric symptoms including catatonia which can be challenging for clinicians to identify as excited catatonia can mimic delirium and psychiatric disorders such as psychosis and mania.