NMDA Receptor Encephalitis May Present As a Pure Psychiatric Episode

Anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis, which can present as a schizophrenic or depressive disorder, is rare and is diagnosed by the presence of immunoglobulin G antibodies to the NR1 subunit of the NMDAR. These researchers examined the occurrence of pure psychiatric syndromes at disease onset or relapse in 571 patients diagnosed with NMDAR encephalitis.

In this group, 23 (4%; median age, 20) presented with isolated psychiatric syndromes — 5 at the first episode of NMDAR encephalitis, and 18 during a relapse. Twenty-one patients were women, 10 of whom had an underlying ovarian teratoma. Magnetic resonance imaging of the brain was abnormal in 10 patients, and 17 had elevated lymphocytic pleocytosis in cerebrospinal fluid. The…