Anti-N-Methyl-D-Aspartate Receptor Encephalitis with Isolated Regressive Behaviour: A Case Report

Abstract

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis, accompanied by a characteristic neuropsychiatric syndrome, predominantly affects young women with ovarian tumors. Although the initial onset of isolated psychiatric symptoms is rare, most cases of anti-NMDAR encephalitis are initially seen by psychiatrists in an emergency room (ER) setting. Furthermore, many of these cases are misdiagnosed as psychiatric disorders. In this report, we discuss a case of a 15-year-old female patient with anti-NMDAR encephalitis. The patient had an initial presentation of sudden-onset regressive behaviour, which is seldom mentioned in the literature. This case may serve as a reminder to psychiatrists, especially ER psychiatrists who are often the first to witness the changing phases of anti-NMDAR encephalitis-associated psychiatric symptoms, to widen the clinical spectrum of this disease. (Hong Kong j.emerg.med. 2016;23:242-245)