A case of anti-N-methyl-d-aspartate (NMDA) receptor encephalitis with an atypical clinical course

Abstract

Anti-N-methyl-d-aspartate (NMDA) receptor encephalitis causes nonspecific symptoms such as fever and headache, which are followed by psychotic symptoms and involuntary movements. On brain magnetic resonance imaging (MRI), no specific findings are noted for almost half of the patients with NMDA encephalitis. Even if MRI abnormalities are present, they may be discreet and reversible. A 10-year-old girl complained of dizziness and headache. She displayed psychotic symptoms and involuntary movements about 60 days after the onset of nonspecific symptoms, and autonomic symptoms 80 days later. MRI-FLAIR images showed high intensity signals distributed in the right hippocampus, insular cortex, amygdala and left hypothalamus. Anti-NMDA receptor encephalitis was diagnosed by detecting anti-NMDA receptor antibodies in the cerebrospinal fluid. Anti-NMDA receptor encephalitis is difficult to diagnose if one only relies on signs and symptoms or on MRI scans. Specific conditions such as psychosis as well as MRI findings in the temporal lobe are clues to diagnose anti-NMDA receptor encephalitis.