Anti- NMDAR Autoimmune Encephalitis Presenting as Acute Psychosis: A Case Report

Anti-NMDA receptor (NMDAR) encephalitis is a recently identified autoimmune disorder with prominent psychiatric symptoms. Patients usually present with acute behavioral change, psychosis, catatonic symptoms, memory deficits, seizures, dyskinesias, and autonomic instability. We present a case of a 13-year old who presented with noticeably chirpiness, excessive talking with unknown people and wandering around the neighborhood without purpose.The main symptoms of the patient and the important clinical findings were irrelevant talking which later developed into slurring of speech, abnormal movements and memory loss.This case is an example of how easily we are misled towards diagnosis based on the present symptoms. The patient suffered the unnecessary stigma of a psychiatric illness, which might stay imprinted on her for a long time. In this report we call for attention to the inclusion of anti-NMDAR encephalitis in the differential diagnosis of acute psychosis. It adds on to show that NMDAR might present in the most unexpected and unpredictable ways, sometimes misleading the patient away from medical help.Prompt diagnosis is critical as early immunotherapy and tumor removal could dramatically affect outcomes.