Behavior outbursts, orofacial dyskinesias, and CSF pleocytosis in a healthy child.

Anti-N-methyl-D-aspartate (NMDA) receptor encephalitis represents a new category of immune-mediated neurologic disorders. Viral encephalitis is often the presumptive diagnosis because of the acute neurologic changes, cerebrospinal fluid lymphocytic pleocytosis, and occasional hyperthermia. We report here the case of a previously healthy 7-year-old boy with new-onset aggressive behavior, seizure activity, and orofacial dyskinesias with cerebrospinal fluid and serum that tested positive for anti-NMDA receptors.