Anti-n-Methyl-d-Aspartate-Receptor (NMDAR) Encephalitis in Association with Ovarian Teratoma

Anti-N-methyl-D-aspartate-Receptor (NMDAR) encephalitis is an autoimmune disorder with a multifaceted presentation that involves memory deficits, psychiatric symptoms, and autonomic instability. This case report describes the classic presentation of Anti-NMDAR encephalitis and highlights its association with ovarian teratomas. We present a 26 -year-old female who came in with new onset seizures and altered mentation who subsequently developed automatism. Electroencephalograms (EEG) showed left frontal spikes and right temporal delta activity. Magnetic resonance imaging (MRI) revealed right temporal hyper-intensity. The diagnosis was established with positive anti-NMDAR antibodies in the cerebrospinal fluid (CSF). The patient was initially treated with steroids and valproic acid, however, her condition progressively worsened. A five-day course of intravenous immunoglobulins (IVIG) was started followed by rituximab. The clinical course was complicated with the patient developing neutropenic fever and cerebrospinal fluid cultures (CSF) growing methicillin-sensitive Staphylococcus aureus (MSSA). She underwent pelvic imaging which showed a right ovarian teratoma. Evidence suggests that removal of ovarian tumor leads to better clinical and mortality outcomes in patients with Anti-NMDAR encephalitis. It is important for the internist to consider paraneoplastic syndromes in patients with Anti-NMDAR encephalitis.