A-58 Unusual Presentation of Anti-NMDAR Encephalitis in a Young Adult Male: A Case Study

Objective To illustrate an unusual presentation of anti-n-methyl-D-aspartate-receptor (anti-NMDAR) encephalitis in a young adult male. Anti-NMDAR encephalitis is an autoimmune-mediated disorder with psychiatric and neurological features that can have lasting impact on cognition. Unique presentation, diagnosis, and assessment are presented. Method Patient is a 28-year-old, Caucasian male with a history of bipolar disorder. Initial hospital presentation was characterized by headache, tremor, and acute altered mental status. Imaging revealed chronic meningitis with diffuse leptomeningeal enhancement/multiple cranial nerve enhancement, hydrocephalus, and Chiari I malformation. He underwent external ventricular drain (EVD) placement and was discharged upon stabilization. He presented 1 month later with symptom recurrence and interval development of hydrocephalus. CSF studies were positive for NMDAR antibody. He was treated with immunotherapy. His 3-month long hospitalization was complicated by acute respiratory failure and intracerebral and intraventricular hemorrhages. He was discharged to 1 month of inpatient rehabilitation. Results Neuropsychological assessment was completed 4 months following discharge from rehabilitation. Visual deficits due to grade 1 papilledema complicated testing. Results revealed frontal deficits (focused attention, processing, and executive functions), with intact verbal learning/memory. This deviates from previous literature that specify verbal memory dysfunction as a core long-term outcome of anti-NMDAR encephalitis. Conclusions This case highlights an unusual presentation and neuropsychological assessment of anti-NMDAR encephalitis. Rare presentations of anti-NMDAR encephalitis can preclude clinical diagnosis and compromise long-term cognitive outcomes if not rapidly and effectively treated. Additionally, mood symptoms may have been early manifestation of the patient’s disease process. Despite acute complications, he demonstrated remarkable functional and cognitive recovery.