Anti-NMDA Receptor Encephalitis in a Patient with a History of Autism Spectrum Disorder

Background: Anti-NMDA receptor (NMDAR) encephalitis is an autoimmunesyndrome characterized by a well-described constellation of neuropsychiatric symptoms. Itsexact pathophysiology is poorly understood, but it is thought to be mediated by autoantibodiesagainst NMDA (N-methyl-D-aspartate)-type glutamate receptors in the central nervoussystem. There is ongoing literature to suggest that patients with autism spectrum disorder(ASD) have evidence of neuroinflammation—or by definition, encephalitis. Objective: To investigate the link between autism spectrum disorder and autoimmune encephalitides. Methods: We present a case of anti-NMDA receptor encephalitis in a patient with autismspectrum disorder. “OP” is a 16-year-old male with a history of attention-deficit/ hyperactivitydisorder (ADHD) and autism spectrum disorder (ASD) who presented with a 3-day historyof acute-onset altered mental status, electroencephalogram (EEG)-corroborated seizures,and slurred speech. Laboratory studies were significant for serum- and cerebrospinal fluid(CSF)-positive NMDA antibodies. The child psychiatry consult-liaison service was consultedfor significant agitation and behavioral dyscontrol. We recommended 1:1 observationfor safety, as well as antipsychotic agents titrated to clinical effect. The patient had a protractedhospital course, but was eventually discharged to an acute rehabilitation facility forcontinued stabilization and therapy. Conclusion: It remains to be seen if the relation between encephalitis and ASD is uni- or bidirectional,that is: whether children with ASD have a genetic diathesis to developing encephalitides(such as those mediated by the NMDAR), or conversely, if deranged or inflamedneuroreceptor processes are implicated in the development of ASD.