NMDA RECEPTOR ENCEPHALITIS PRESENTING AS PARTIAL STATUS EPILEPTICUS: CASE REPORT AND DISCUSSION

OBJECTIVE: Challenging differential diagnosis. BACKGROUND: Anti-NMDA receptor encephalitis develops in 5 distinct phases: 1. The Prodrom, 2.The Psychotic phase, 3. The Non-responsiveness, 4. Hyper-kinetic phase 5. Gradual recovery. CASE REPORT: We describe the case of a 17 years old right handed female with a complex partial seizure two weeks prior followed by psychiatric manifestations such as personality changes, anxiety and psychotic symptoms. She had also fluctuating short term memory loss, linguistic and developmental regression, echopraxia and occasionally vague autonomic instabilities. She was admitted when she progressed to mutism. Her EEG showed numerous focal electrographic seizures arising from the left temporal hemisphere and continuous slowing in the left temporal and central regions consistent with partial status epilepticus. Her noncontrast head CT was unremarkable while her contrast brain MRI revealed increased T2 signal within the cortical left temporal and parietal region. NMDA receptor encephalitis was high on our differential and her status epilepticus was considered autoimmune in origin. Her seizures were eventually controlled after multiple AED’s including Keppra, Dilantin, Valproic Acid and Solumedrol. She underwent a lumbar puncture that was unremarkable and her infectious work up was negative. Her CSF NMDA receptor antibody returned positive 10 days later while the paraneoplastic panel was negative. Her oncological work up was unremarkable and no tumor was found on a whole body PET scan and abdominal/vaginal ultrasound. Her symptoms have been reversed after 5 curses of plasmapheresis followed by IVIG. Her repeated MRI was improved and her EEG was normal. She had mild behavioral and cognitive dysfunctions but she was discharge home with outpatient rehabilitation. CONCLUSIONS: This case emphasizes the particular challenges in the adolescent population of early recognition of organic origin of neuropsychiatric disorders before progressive loss of neurological functions is evident. Early diagnosis is desirable as immunosuppressive therapy may be most effective at this time and may improve the end point of the disease. Disclosure: Dr. Proteasa has nothing to disclose. Dr. LaJoie has nothing to disclose. Dr. Maytal has nothing to disclose.