Comparisons between Psychiatric Symptoms of Patients with Anti-NMDAR Encephalitis and New-Onset Psychiatric Patients

Abstract

Background: Anti-N-methyl-<smlcap>D</smlcap>-aspartate receptor (NMDAR) encephalitis is a potentially lethal autoimmune disease. Early diagnosis and immunotherapy can improve prognosis; however, early prominent psychiatric symptoms have led to misdiagnosis in numerous cases, delaying diagnosis and treatment. This study aimed to explore the clinical features and psychiatric symptoms of anti-NMDAR encephalitis and the association between antibody titers and psychiatric symptoms. Methods: In this retrospective study, 43 patients with anti-NMDAR encephalitis and 70 new-onset psychiatric patients were enrolled. Psychiatric symptoms were assessed by trained psychiatrists using the Positive and Negative Syndrome Scale. Results: There were significant differences in psychiatric symptoms between the antibody-positive and antibody-negative groups. The item scores for poor rapport (p < 0.01), difficulty in abstract thinking (p < 0.01), lack of spontaneity and flow of conversation (p < 0.01), unusual thought content (p < 0.01), and disorientation (p < 0.01) were significantly higher in the antibody-positive group, while the item scores for delusions (p < 0.01) were significantly higher in the antibody-negative group. These differences all remained significant after Holm-Bonferroni correction. In the antibody-positive group, scores for each item, subscale, and factor increased with increases in antibody titer, particularly for delusions (p < 0.05) and hallucinatory behavior (p < 0.01). Thereafter, only hallucinatory behavior remained significant. Conclusions: Patients with anti-NMDAR encephalitis with initial psychiatric symptoms may have the following characteristics: poor rapport, difficulty in abstract thinking, lack of spontaneity and flow of conversation, unusual thought content, and disorientation. Furthermore, antibody titer may be associated with psychiatric symptom severity, especially in hallucinatory behavior.

Autoimmune psychosis: an international consensus on an approach to the diagnosis and management of psychosis of suspected autoimmune origin

“…Importantly, the presentation of patients with NMDAR-Ab encephalitis, according to current diagnostic criteria 11 , rarely maps easily onto existing diagnostic constructs for schizophrenia-spectrum disorders 41,[43][44][45] . Moreover, the majority of studies have failed to find clinically meaningful differences in severity across multiple symptom domains between seropositive and seronegative subjects with psychosis [46][47][48] .…”

NMDAR autoantibodies in psychiatric disease - An immunopsychiatric continuum and potential predisposition for disease pathogenesis

“…However, an NMDARE is proven if just one of the clinical features is present and CSF immunoglobulin G (IgG) NMDAR N1 antibodies are detected, according to the Graus criteria [ 4 ]. The onset of NMDARE is often characterized by psychiatric symptoms [ 5 , 6 ]. Nevertheless, NMDAR autoantibodies are also detected in psychiatric patients who fail to fulfill NMDAR-encephalitis criteria [ [7] , [8] , [9] ].…”

Effect of Clozapine on Anti-N-Methyl-D-Aspartate Receptor Encephalitis With Psychiatric Symptoms: A Series of Three Cases

“…It was reported that NMDAR hypofunction was a potential mechanism resulting in schizophrenia, which complemented the most widespread explanatory mechanism of “dopamine hypothesis” for schizophrenia (Ramanathan et al, 2014). Some scholars declared that NMDAR dysfunction was the “final common pathway” underlying the pathogenesis of schizophrenia, and it was associated with both positive and negative symptoms (Wang et al, 2017). Anti-NMDAR antibodies were also found in schizophrenia patients (Koshiyama et al, 2018; Xie and Huang, 2018).…”