Cycloid psychosis as a psychiatric expression of anti‐NMDAR encephalitis. A systematic review of case reports accomplished with the authors' cooperation

Abstract

Objective We reviewed the psychotic symptoms of anti‐NMDA receptor encephalitis (NMDARE) to differentiate its presentation from those found in a primary psychiatric disorder. We hypothesized that the cycloid psychosis (CP) phenotype would be a frequent clinical presentation in the psychiatric phase of NMDARE. Method A systematic literature review in PubMed of all case reports published on NMDARE was performed from database inception to March 2020. We included all cases where psychotic symptoms were reported and whose diagnoses were confirmed by the presence of anti‐NMDAR antibodies in the cerebrospinal fluid (CSF). An email including a short test (CP phenotype, Perris and Brockington's criteria) was sent to all case report authors asking them to describe the psychotic symptoms. Results We identified 335 case reports fulfilling our criteria, and the authors of 200 replied. Our analyses were based exclusively on those answers and data extracted from the articles. Median patient age was 25 years (+‐11.4), 81% were female, and 39% had an ovarian teratoma. A complete CP phenotype was identified in 175 patients (87%). These were acute psychotic episodes with a sudden onset and a fluctuating clinical pattern mostly characterized by confusion (97%), delusions (75%), hallucinations (69%), motility disturbances (87%), and mood oscillations (80%). Conclusion The complete CP phenotype was frequently the expression of psychotic symptoms in NMDARE. We suggest that patients with a first psychotic episode who initially exhibit the CP phenotype should undergo CSF analysis to determine whether antibodies against neuronal cell surface or synaptic receptors are present to rule out a possible diagnosis of autoimmune encephalitis.

Traumatic Events, Social Adversity and Discrimination as Risk Factors for Psychosis - An Umbrella Review

“…We suggest that there are several reasons why prior knowledge may be challenged, thus, resulting in imprecise neurobiological encoding of priors (8). Specifically, imprecise encoding of prior knowledge may not only result from predominantly biological causes [e.g., anti-NMDA receptor antibodies in some psychotic states (28)], but also arise in complex situations characterized by threatening experiences and potentially uncontrollable social interactions as, e.g., experienced by previously traumatized or ethnically discriminated individuals (8,29). Previous studies found varying prevalence rates between 0 and 55% of PTSD in patients suffering from schizophrenia spectrum disorders (30), suggesting a rather high prevalence of PTSD which may often remain overlooked in clinical settings (31).…”

Case Report: Anti-N-Methyl-D-Aspartate Receptor Encephalitis Manifesting With an Isolated Psychiatric Episode and Normal Ancillary Tests

“…However, one study argues that its psychiatric features meet the criteria for cycloid psychosis (CP). While not specific for anti-NMDAR encephalitis, CP delineates acute psychotic episodes with a fluctuant clinical pattern mostly characterized by confusion, psychosis, movement disorders (including catatonia) and oscillations of mood ( 8 ). Our patient displayed a triad of behavior alterations (with agitation and aggression), psychosis and catatonia.…”

“…As illustrated by our case, these psychiatric features develop rather sudden ( 1 ), while primary psychoses tend to have a more insidious onset. The course of the disease also differs; while psychiatric symptoms in anti-NMDAR encephalitis tend to fluctuate ( 8 ), they remain more stable in primary psychoses. Additionally, as in our case, the psychotic symptoms tend to be treatment-resistant which often require higher doses or combinations of antipsychotics ( 9 ).…”

The Importance of Cerebrospinal Fluid Investigation in First-episode Psychosis

“…This has driven some authors to search for a specific psychiatric phenotype to identify AE patients during an early disease stage. Giné-Servén et al [17] propose cycloid psychosis (CP) as a risk psychiatric phenotype for anti-NMDAR encephalitis. CP is mainly characterized by an acute psychotic episode with a sudden onset and fluctuant clinical pattern with confusion, delusions, hallucinations, motility disturbances (including catatonia), and mood oscillations.…”

“…CP is mainly characterized by an acute psychotic episode with a sudden onset and fluctuant clinical pattern with confusion, delusions, hallucinations, motility disturbances (including catatonia), and mood oscillations. While not specific for anti-NMDAR encephalitis, Giné-Servén et al [17] argue that identifying this risk phenotype in the early psychotic stage of the disease would ensure rapid diagnosis and initiation of treatment before the onset of neurological symptoms.…”