Anti-NMDA receptor encephalitis causing prolonged nonconvulsive status epilepticus

Abstract

Anti-NMDA receptor encephalitis is characterized by dyskinesias, psychosis, and seizures1 secondary to antibodies to the NR1-NR2B heteromer of the NMDA receptor.2 This syndrome, more common in women, is often related to an ovarian tumor1; the prognosis is better if the tumor is identified within 3 months of onset. Our case had nonconvulsive status epilepticus lasting 6 months, with marked improvement following removal of the ovarian tumor. ### Case report. A 35-year-old woman, previously healthy and without history of psychosis, had a 3-week history of progressive headaches, short-term memory loss, and irritability. On admission, she was psychotic, requiring physical and chemical restraints. She was unable to follow commands, had echolalia, and had occasional dystonic posturing of her limbs. One week later, she became unresponsive to external stimuli. An EEG demonstrated persistent nonconvulsive status epilepticus (NCSE). Initial CSF studies were remarkable for a lymphocytic pleocytosis with 386 leukocytes. Brain MRI showed diffusion-weighted imaging hyperintensity in the right medial temporal lobe transitioning to fluid-attenuated inversion recovery hyperintensity on repeat imaging (figure 1A). Tests for multiple viral and bacterial pathogens, including herpes simplex virus, were negative. A paraneoplastic …