Ovarian teratoma-associated anti-NMDAR encephalitis: a single-institute series of six patients from China

Purpose: Ovarian teratoma-associated anti-N-methyl-D-aspartate receptor encephalitis is a rare disease with uncertain etiology and pathogenesis. The disorder is severe and rare with a great impact on young adults. This study aimed to improve the awareness of the disease from experience in our single center.

Methods: Between July 2012 and December 2019, six patients with ovarian teratoma-associated anti-N-methyl-D-aspartate receptor encephalitis were enrolled in Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University. All patients' data like manifestations, laboratory and radiological data, treatment, and follow-up were reviewed.

Results: Typical psychotic symptoms, memory, and consciousness disorders accompanied by seizures were observed in all patients from this study. All six patients showed positive signals in serum and cerebrospinal fluid samples for N-methyl-D-aspartate receptor and received immunotherapy. Three patients underwent unilateral oophorocystectomy and the other three underwent unilateral oophorectomy through minimally invasive surgeries, including laparoscopic and single-port laparoscopic surgeries. The median follow-up time 24.5 months (range from 6 to 93 months). No death occurred. Two patients had recurrent psychotic symptoms while the left four patients had no mental symptoms or tumor recurrence during postoperative follow-up.

Conclusions: For patients with clinical manifestations of unexplained acute psychiatric symptoms accompanied by seizures, memory, and consciousness disorders, the possibility of anti-N-methyl-D-aspartate receptor encephalitis should be considered. To confirm the diagnosis, examinations of anti-N-methyl-D-aspartate receptor antibodies need to be completed as early as possible. Immunotherapy and tumor location should be given in time once the diagnosis is defined. We recommended removing the tumor as soon as possible without concerning whether the patient is in the acute phase or not. The surgical procedure should be decided based on pathology, age, fertility desire, and patients' requirements and it should be ensured that tumors are completely removed during operation. Postoperative follow-up is particularly important.