Anti-N-methyl-D-aspartate Receptor (NMDAR) Encephalitis: Neuronal Burden of a Comorbid Ovarian Teratoma

ABSTRACT

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is a disease that is characterized by acute psychiatric symptoms, seizures, and central hypoventilation. Patients with anti-NMDAR encephalitis exhibit speech alterations, insomnia, seizures, and movement disorders. We describe a previously healthy 6-year-old girl who presented with seizures, disorientation, and fever. Over the five weeks of treatment, the patient exhibited progressive neurologic symptoms, including a change in mental status. Her serum and cerebrospinal fluid contained high titers of antibodies against the NMDAR, and she was diagnosed with anti-NMDAR encephalitis. She was treated with plasmapheresis, steroid pulse therapy, intravenous immunoglobulins, and repeated doses of rituximab. After the patient was diagnosed with a concomitant ovarian teratoma, a unilateral salpingo-oophorectomy was performed. A histopathologic examination revealed that neuronal elements accounted for 60% of the resected ovarian teratoma. The patient's clinical symptoms and antibody titers improved after the surgical treatment and rituximab therapy. These observations suggested that patients with high titers of anti-NMDAR antibodies should be examined for the presence and quantity of neuronal components in concurrent ovarian teratomas.