1941 Ovarian Dermoid Cyst as the Cause of Anti-Nmda Receptor Encephalitis: A Case Series

Study Objective Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis is an autoimmune condition often presenting in the form of a neuropsychiatric disorder. Ovarian dermoid cyst has been described as a possible instigator of this state with surgical therapy often leading to substantial clinical improvement. We aim to describe our hospital's experience and highlight the importance of ultra sound in the diagnosis and treatment of Anti-NMDAR encephalitis. Design A case series. Setting All women were treated at the gynecology department of a tertiary teaching hospital between January 2013 and December 2018. Patients or Participants We describe 3 cases of anti-NMDAR encephalitis. In the first case a 33 y/o woman presented with headaches, dizziness, and seizures for the first time in her life and later, developed aphasia. In the second case, a 37 y/o woman was referred to the emergency room with acute confusion, delusions and hallucinations and in the third case, a 32 y/o woman appeared with psychosis and seizures. All three were diagnosed with ANTI NMDA antibodies and an ultrasound examination revealed a dermoid cyst ranging from 1 to 4 cm, and in one case the cyst was not detected by CT-scan. Interventions All women underwent ovarian resection and continued immunosuppressive medical therapy with gradual improvement in their condition. Measurements and Main Results We show that even small dermoid cysts may evoke antibody titer rise emphasizing the importance of performing early gynecologic ultrasound for women with new-onset encephalitis. Conclusion ANTI-NMDAR encephalitis caused by dermoid cyst is an important entity which can easily go misdiagnosed. Early cystectomy or ovarian resection and immunosuppressive treatment are key elements in the management of such cases.