Othello syndrome in Parkinson's disease: a systematic review and report of a case series

Parkinson disease psychosis: from phenomenology to neurobiological mechanisms

Parkinson disease (PD) psychosis (PDP) is a spectrum of illusions, hallucinations and delusions that are associated with PD throughout its disease course. Psychotic phenomena can manifest from the earliest stages of PD and might follow a continuum from minor hallucinations to structured hallucinations and delusions. Initially, PDP was considered to be a complication associated with dopaminergic drug use. However, subsequent research has provided evidence that PDP arises from the progression of brain alterations caused by PD itself, coupled with the use of dopaminergic drugs. The combined dysfunction of attentional control systems, sensory processing, limbic structures, the default mode network and thalamocortical connections provides a conceptual framework to explain how new incoming stimuli are incorrectly categorized, and how aberrant hierarchical predictive processing can produce false percepts that intrude into the stream of consciousness. The past decade has seen the publication of new data on the phenomenology and neurobiological basis of PDP from the initial stages of the disease, as well as the neurotransmitter systems involved in PDP initiation and progression. In this Review, we discuss the latest clinical, neuroimaging and neurochemical evidence that could aid early identification of psychotic phenomena in PD and inform the discovery of new therapeutic targets and strategies.

Clinical Characterization, Course, and Treatment of Othello Syndrome: A Case Series and Systematic Review of the Literature

BACKGROUND

Othello syndrome (OS) is a condition characterized by a delusion of jealousy that one's spouse is having extramarital affairs. As in the eponymous Shakespearean tragedy, there is an unfortunate risk of violence. For patients with these symptoms, consultation-liaison psychiatrists may be asked to assist with evaluating the differential diagnosis, assessing safety, and developing treatment options.

OBJECTIVE

This study's objective was to solidify current knowledge of the clinical presentations and management of OS through a systematic review of the literature and description of 2 new cases.

METHODS

We conducted a literature search from the start of relevant databases through August 2023 to identify English language case reports of adults (≥18 years) with OS that described clinical evaluations, biological treatments, and outcomes. We extracted demographics, proposed etiologies, treatment choices and responses, duration of delusions, comorbid psychiatric symptoms, neuro-radiographic findings, and presence of physical violence. We reported clinical findings for 2 new cases.

RESULTS

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we screened 705 abstracts and conducted full-text reviews of 118 articles to identify 73 cases published from 1983 to 2023 meeting inclusion criteria. The mean age was 58.2 years with male predominance (M:F = 1.88). Etiologies included primary psychiatric disorders (16, 22%), other medical conditions (38, 52%), and medications or other substances (19, 26%). Delusional disorder, cerebrovascular accident, and dopaminergic agonists were the most common etiologies, respectively, in these groups. Antipsychotics were the most common treatment (57, 78%). Symptom remission was reported in 51 (70%) cases. The average duration of OS was 39.5 months. Of 32 cases reporting brain imaging insults, 12 of 20 (60%) showed right-sided lesions, and 8 of 20 (40%) showed left-sided lesions, with 9 of 32 (28%) located in the frontal lobes. The most commonly co-existing psychiatric symptom was depression (14, 19%). Violence was reported in 25 cases (34%). Our 2 new cases were consistent with these findings.

CONCLUSIONS

OS may be a manifestation of several neuropsychiatric conditions, primarily delusional disorder, cerebrovascular accident, Alzheimer's dementia, and the use of dopaminergic agonists. One-third of cases include violent behaviors. It appears to respond to antipsychotic medications, but treatment is delayed more than 3 years on average. Available data have not localized OS to a specific brain region.

Violence and delusional jealousy in Parkinson's disease

Psychosis in Parkinson's disease (PD) can have a hugely detrimental effect on patient outcomes and quality of life. It can be a feature of PD itself, or can be exacerbated by the very pharmacological agents that are prescribed to treat the motor symptoms of the disease. The treatment of psychosis in PD is often complex, with clinicians having to balance the debilitating physical symptoms of PD against the risk of exacerbating the psychosis. We describe the case of an octogenarian who presented with violence motivated by delusional jealousy in the context of PD, who was treated in a specialist psychiatric inpatient environment.

Frequency and Characteristics of Psychosis in Parkinson's Disease: A Systematic Review and Meta-Analysis

BACKGROUND

Psychotic symptoms are highly frequent in Parkinson's disease (PD) patients and are associated with poor prognosis. They include hallucinations, delusions, and minor psychotic phenomena, including sense of presence, passage hallucinations, and illusions.

OBJECTIVE

To evaluate the frequency of psychosis in PD patients.

METHODS

A systematic review and meta-analysis of clinical trials, prospective and retrospective cohort studies, case-control studies, and cross-sectional studies reporting the frequency of psychosis, hallucinations, and delusions in PD.

RESULTS

Electronic database search wielded 3536 articles, an additional 91 were identified through citation chaining. Of these, 163 were fully inspected, 57 removed, and 106 included as relevant for neuropsychiatric events frequency, with 32 meeting our inclusion criteria (psychosis and/or specific psychotic phenomena). The pooled frequency of psychosis was 20.7% (95% CI 14.5 to 28.6; I2 = 94%, 15 studies; combined n = 2919). None of the pre-defined meta-regressions or subgroup analyses were statistically significant or helped explain the statistical heterogeneity. The pooled frequency of any form of hallucination was 21.6% (95% CI 14.7 to 30.6; I2 = 95%; 18 studies; combined n = 3161). Duration of PD at baseline and mean baseline Hoehn & Yahr stage helped explain the statistical heterogeneity in the meta-analysis of hallucinations.

CONCLUSION

Based on the available evidence, around a fifth of PD patients experience psychosis or hallucinations. The risk of developing hallucinations is likely moderated by the disease duration, Hoehn & Yahr stage, and the cognitive status.