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

Abstract

Introduction Psychosis in Parkinson’s disease (PD) is common and consists of hallucinations, illusions, and delusions. Among the latter, delusional jealousy, also named Othello syndrome (OS), might impair the quality of life of both patients and their partners. We aimed to perform a systematic review and report a series of PD patients presenting with OS. Methods A systematic review research was performed in PubMed database, excluding non-English articles, single case reports, reviews and neuropathology articles, comments, and articles concerning OS associated with deep brain stimulation (DBS) and levodopa-carbidopa intestinal gel infusion. We also described eleven PD patients (9 M and 2 F) with OS, identified in a cohort of consecutive 153 patients, comparing them with eleven matched no OS (nOS) PD subjects taken from the same cohort. Results We included eight articles (four case series and four cross-sectional studies). OS resulted more common among males than females. We did not find higher levodopa dose and levodopa equivalent dose for dopamine agonists and for all anti-parkinsonian drugs in our OS group. In our case series, OS patients showed visual hallucinations (p=0.001) and a trend to have depression (p=0.080) more frequently than nOS ones. Conclusions OS is not a rare disorder in PD, probably due not only to abnormal dopaminergic stimulation but also to serotonergic dysfunction in biologically predisposed subjects. Visual hallucinations and other concomitant psychiatric diseases, in particular depression, might represent a risk factor for the OS development.

Violence and delusional jealousy in Parkinson’s disease

“…Although further studies are needed to determine the absolute risk increase of developing delusional jealousy after taking a dopamine agonist, treatment with these medications may be a risk factor for developing the disorder. This is supported by the findings that delusional jealousy occurs at an increased rate (5%) in patients with PD who are prescribed dopamine agonists,10 and that 64%–100% of patients with PD with delusional jealousy have been treated with a dopamine agonist 15 16. It has been postulated that the behavioural side effects of dopamine agonists such as aggression and psychosis are mediated by D2-receptor agonism; these receptors are implicated in reward and reinforcement neural pathways, and it is via antagonism of these receptors that antipsychotic drugs exert their effects 8.…”

“…With particular relevance to this case, dopamine agonist use in PD has been implicated in delusional jealousy,10 hypersexuality11 and impulse control disorders 12 13. Delusional jealousy has an estimated prevalence of 1.1%–7.2% in PD 10 14–16. In systematic reviews of case reports and cross-sectional studies, the majority of patients with delusional jealousy were males in the early-middle stages of the disease and had relatively preserved cognition 15 17.…”

“…However, there must be other important patient factors since the disorder is also found in patients who are not treated with dopamine agonists. There are several theories that seek to explain this apparent contradiction, that low levels of dopamine predispose patients with PD to develop psychosis, as well as elevated levels of dopamine brought about by dopamine agonists 15. It has been suggested that overstimulation or sensitisation of dopaminergic receptors in the mesolimbic system can increase risk of psychosis in patients with PD who have a premorbid predisposition to develop the condition 18.…”

Othello syndrome and dopamine dysregulation syndrome

“…The association between OS and DDS is uncommonly described. In a systematic review published in 2021, DDS was observed in one out of 32 OS patients 9 . The link of causality remains to be determined.…”

“…In a systematic review published in 2021, DDS was observed in one out of 32 OS patients. 9 The link of causality remains to be determined. For some, both syndromes are assimilated to 'hyperdopaminergic' behaviours sharing the same physiopathology of hyperstimulation of limbic circuits of the basal ganglia, coupled with a lack of cortical inhibition.…”