Anti-N-Methyl-D-Aspartate Receptor Encephalitis: A Challenging Diagnosis in the Emergency Department.

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an underdiagnosed disease that has been described thus far only in case series. Patients, the majority of which are females, develop neuropsychiatric symptoms that can often be misdiagnosed as purely psychiatric illness. Although teratomas are nearly pathognomonic for anti-NMDAR encephalitis, these are less common in children and males. This case illustrates some common features of anti-NMDAR encephalitis and some of the challenges in diagnosis.