Abstract
A few published reports suggest the possible co-occurrence of anti-N-methyl-D-aspartate receptor antibody encephalitis in patients with bipolar disorder who show atypical presentations of herpes encephalitis. We report an adult woman with a known case of bipolar 1 disorder who showed an atypical presentation of a depressive episode with psychosis and herpes simplex encephalitis. She did not improve with an adequate dose of psychotropic medications; instead, her condition continued to decline and she started to display signs of lethargy, agitation, confusion, memory deficits, wordfinding difficulties, difficulty swallowing, disorganized behavior, and jerky movement. Her vital signs were normal and her neurological examination was unremarkable. Computer tomography and magnetic resonance imaging tests of her brain were normal. She developed a sudden fever and became disoriented. Cerebrospinal fluid results confirmed viral encephalitis, and she tested positive for herpes simplex virus type 1 DNA. Patients with known psychiatric disorders who show any unusual presentation of psychiatric features in combination with cognitive impairments, neurological symptoms, and abnormal movements should be investigated thoroughly for possible secondary psychiatric illness. A high index of suspicion for the underlying etiology, with a broad approach to test for infectious diseases and various neuronal autoantibodies, can prompt correct diagnosis and management.