Anti-N-methyl-D-aspartate Receptor Encephalitis as a Paraneoplastic Presentation of Mature Ovarian Teratoma.

BACKGROUND Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a potentially fatal form of autoimmune encephalitis that involves autoantibodies directed against the NR1 subunit of the receptor. This leads to dysregulation of neurotransmission and resultant psychotic and neuroanatomical symptoms. Anti-NMDAR encephalitis classically presents in women who have ovarian teratomas, but it also has been associated with a preceding herpes infection, testicular germ cell tumor, small cell lung cancer, and neuroblastoma.