34-year-old female presented with 20 pounds weight-loss and altered mental status. Her condition started under a year ago, when she had episodes of bizarre behavior consisting of losing balance, rubbing against the walls, turning things on, forgetting her name, crying and shaking her legs and arms, resolving spontaneously.  On presentation, the patient would minimally interact and appeared catatonic. On neurological examination, she had had symmetric hyperreflexia in all extremities, but otherwise non-focal. The patient had a generalized tonic-clonic seizure in the hospital and a cardiac arrest with pulseless electrical activity after which she was resuscitated. CSF was unremarkable. NMDAR antibodies tested in CSF via Immunofluorescence Assay was negative.  Virology panel was negative except for Hepatitis B. Other autoimmune antibodies as ANA, RF, ANCA, Anti TPO antibody were also negative. Liver enzymes were mildly elevated.

MRI of the brain showed several scattered foci of acute infarcts in the left cerebellar hemisphere, right frontal lobe and right parietal lobe but no evidence of T2 hyperintense signal in the temporal lobe. CT scan of the pelvis revealed a 9cm ovarian-teratoma. EEG was consistent with marked diffuse encephalopathy. As the suspicion for an autoimmune encephalitis was high, IVIG therapy was initiated and the teratoma was removed surgically.