P.033 Novel presentation of NMDA receptor encephalitis

Abstract

Background: NMDA receptor encephalitis (NMDARE) is associated with pre-existing psychiatric symptoms and seizure disorders. It is not typically associated with elevated ICP. Diagnostically, EEG findings in NMDARE are characteristic as are the pathological features of ovarian teratomas associated with this disease. We report a patient who tested positive for NMDARE however presented with features not known to be associated with the disease including elevated ICP, atypical EEG findings and grossly atypical features on pathological section. Results: A 26 year old woman presented with psychiatric symptoms and status epilepticus. On examination, she was found to have papilledema and eleveated ICP on measurement. Her imaging and EEG demonstrated atypical findings, not consistent with NMDARE. CT scan of the abdomen demonstrated an adnexal mass. CSF studies eventually tested positive for NMDARE and following removal of her ovarian teratoma, the pathology demonstrated atypical findings for lesions associated with NMDARE classically. Conclusions: NMDARE is a new entity, which has historically shown a typical clinical course. Our case demonstrates a previously undescribed presentation of NMDARE with elevated ICP, atypical EEG findings and unique pathology of the associated ovarian teratoma.