Case Presentation: We present a previously healthy 22-year-old female presenting with disorganized behaviors, restlessness and sub-acute decline in mental status. There was no other relevant medical, personal or familial history. However, she had stressors three days before initial change in behavior, such as infidelity with her significant other and she had tremendous anxiety and guilt regarding the incident. Her behavior continued to decline during admission. Four days after admission, the patient developed repetitive left hand motions visual and auditory hallucinations, and echolalia.
Her initial laboratory results including cerebrospinal fluid analysis were unremarkable. Her culture results were negative. Other infectious workup including syphilis, HSV, Cryptococcus, West Nile virus, Lyme were negative. MRI head was unremarkable. She was found have a right ovarian dermoid cyst on ultrasound. Electroencephalography reported diffuse delta activity 1-3 Hz with superimposed bursts of rhythmic 20–30 Hz beta frequency activity. Extensive workup for autoimmune diseases were done and found to be positive for anti-NMDA receptor antibodies. Patient underwent laparoscopic right oophorectomy for ovarian teratoma. Surgical pathological examination demonstrated mature cystic teratoma. The patient began treatment with Methylprednisolone and IVIG the day following surgery. Due to lack of improvement following tumor resection and corticosteroid and IVIG therapy, Rituximab was administered to our patient along with the initiation of plasma exchange.
Discussion: NMDA receptor antibody encephalitis is a classic example of antibody-mediated paraneoplastic encephalitis commonly associated with ovarian teratoma. It should be considered in patients presenting with acute or sub-acute onset psychiatric symptoms who develop movement or autonomic disorder. Delta brush is a pattern on electroencephalography that can be observed in some of the patients with anti-NMDA receptor encephalitis, but it is not a constant feature.
There are cases describing nonspecific prodromal symptoms or infectious triggers for immunological response leading immune dysregulation in patients with autoimmune diseases. We presumed that our patient’s emotional stress triggered immune dysregulation, which ultimately resulted in anti-NMDA encephalitis. Follow up treatment of patients diagnosed with anti-NMDA autoimmune encephalitis should include stress management, behavioral intervention to prevent stress induced immune dysregulation as this could play a role in preventing relapse. The role of stress in the pathogenesis of anti-NMDA encephalitis and relapse after treatment should be clarified by prospective studies. We also recommend considering future fertility when making therapeutic decisions in women of reproductive age.
Conclusions: Screening for anti-NMDA receptor encephalitis should be considered in patients presenting with acute or sub-acute onset psychiatric symptoms who develop neurologic or autonomic disorder. It is important that fertility preservation should be discussed in women of reproductive age. In addition, stress management should be considered in patients with history of anti-NMDA autoimmune encephalitis as play a role in preventing relapse.