Impulse control disorders in Parkinson's disease patients with RLS: a cross sectional-study

Prevalence and clinical profile of patients with restless legs syndrome in Parkinson's disease: A meta-analysis

INTRODUCTION

Restless legs syndrome (RLS) is a sensorimotor disorder of sleep/wake regulation characterized by an urge to move the legs accompanied by a wide range of sensory symptoms, mainly affecting the lower limbs. An increased incidence of RLS has been demonstrated in Parkinson's disease (PD) and has been associated with severe motor and non-motor manifestations. We aimed to provide a reliable estimate of RLS prevalence and the clinical features associated with its occurrence in PD (PD-RLS).

METHODS

We performed a systematic literature search up to January 2024 using PubMed, Scopus, and PsycINFO databases. Articles were included if they provided data on PD patients with or without RLS, and these proportions were used to estimate the prevalence of PD-RLS. Clinical profile associated with PD-RLS was explored by comparing the clinical characteristics of PD patients with and without RLS.

RESULTS

Forty-six studies were included in the meta-analysis. Pooled RLS prevalence was 20 % of a total sample of 6990 PD patients and was associated with female sex, mixed motor phenotype, worse motor disturbances and functional disability, and a wide range of non-motor symptoms such as sleep disorders, cognitive and autonomic dysfunctions, and more severe neuropsychiatric manifestations. Sensitivity analyses indicated significant associations of PD-RLS with variables related to dopaminergic therapy. No association was found with serum ferritin, serum iron and hemoglobin levels.

CONCLUSIONS

The prevalence of PD-RLS exceeds that reported in the general population, suggesting the existence of a relationship between the two disorders. Dopaminergic treatment seems to play an ambivalent role relieving, worsening or "mimicking" RLS manifestations. However, the clinical profile of PD-RLS patients, characterized by a greater severity of non-motor symptoms, also suggests that neurotransmitter systems other than the dopaminergic one are involved in PD-RLS etiology.

Prevalence of depression or depressive state in patients with restless legs syndrome: A systematic review and meta-analysis

Restless legs syndrome (RLS) is a common sleep-related disorder characterized by limb discomfort and the urge to move them when at rest, especially in the evening or at night. Although depression is often linked to various conditions, no systematic review has assessed depression prevalence in patients with RLS after the latest diagnostic criteria revision. This systematic review and meta-analysis aimed to investigate the depression and depressive state prevalence among patients with RLS. We systematically searched databases up to November 2022 and performed meta-analyses of the depression prevalence using a random-effects model and a meta-regression analysis to explore the relationship between the prevalence and severity of depression and factors such as age and RLS severity. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we analyzed 24 studies with 2039 patients. The pooled depression or depressive state prevalence, mostly defined by questionnaire scores, was 30.39 %. Nine studies reported the proportion of patients taking antidepressants (pooled rate: 3.41 %). No specific factors related to the prevalence or severity of depression were identified in patients with RLS. These findings highlight the significant prevalence of depression and underscore the need for future research with standardized diagnostic interviews and consistent methodologies across multi-site studies.

Assessing impulse control behaviors in early Parkinson's disease: a longitudinal study

Objective

Impulse control behaviors (ICBs) frequently coexist with Parkinson's disease (PD). However, the predictors of ICBs in PD remain unclear, and there is limited data on the biological correlates of ICBs in PD. In this study, we examined clinical, imaging, and biological variables to identify factors associated with longitudinal changes in ICBs in early-stage PD.

Methods

The data for this study were obtained from the Parkinson's Progression Markers Initiative, an international prospective cohort study that evaluates markers of disease progression in PD. We examined clinical, imaging, and biological variables to determine their associations with ICBs over a period of up to 5 years. Cox regression models were employed to investigate the predictors of ICBs in early-stage, untreated PD.

Results

The study enrolled 401 individuals with PD and 185 healthy controls (HC). At baseline, 83 PD subjects (20.7%) and 36 HC (19.5%) exhibited ICBs. Over the course of 5 years, the prevalence of ICBs increased in PD (from 20.7% to 27.3%, p < 0.001), while it decreased in HC (from 19.5% to 15.2%, p < 0.001). Longitudinally, the presence of ICBs in PD was associated with depression, anxiety, autonomic dysfunction, and excessive daytime sleepiness (EDS). However, there was no significant association observed with cognitive dysfunction or motor severity. Treatment with dopamine agonists was linked to ICBs at years 3 and 4. Conversely, there was no association found between ICBs and presynaptic dopaminergic dysfunction. Additionally, biofluid markers in baseline and the first year did not show a significant association with ICBs. A predictive index for ICBs was generated, incorporating three baseline characteristics: anxiety, rapid eye movement sleep behavior disorder (RBD), and p-tau levels in cerebrospinal fluid (CSF).

Conclusion

During the early stages of PD, there is a notable increase in ICBs over time. These ICBs are associated with depression, anxiety, autonomic dysfunction, EDS, and the use of dopaminergic medications, particularly dopamine agonists. Anxiety, RBD, and p-tau levels in CSF are identified as predictors for the incident development of ICBs in early PD. Further longitudinal analyses will provide a more comprehensive understanding of the associations between ICBs and imaging findings, as well as biomarkers. These analyses will help to better characterize the relationships and implications of these factors in the context of ICBs in early PD.

Relationship between sleep disorders and neuropsychiatric symptoms in Parkinson's disease: A narrative review

Aim: The objective of this narrative review was to describe the versatile links between mental status and sleep in patients with Parkinson's disease. Methods: We searched randomized controlled studies, observational studies, meta-analyses, systematic reviews, and case reports written in English in PubMed during 2015 - 2021. Additionally, to ensure the completeness of the review, a second, more in-depth literature search was performed using the same electronic database with the search inquiries of increased specificity. Results: The information on pathophysiology, epidemiology, clinical features and risk factors was extracted and formed the basis for this review. Despite how widespread sleep disorders in Parkinson's disease are, there is no systematic information about their association with neuropsychiatric symptoms, such as depression, anxiety, impulse control disorders, apathy, cognitive impairment and psychosis. In this review, we described relationships between these non-motor symptoms of Parkinson's disease, their timeline occurrence, gap in knowledge and perspectives for further research. We suppose that early treatment of sleep disorders in patients with Parkinson's disease can reduce the incidence and extent of neuropsychiatric symptoms. Conclusion: We have demonstrated multiple, multidirectional relationships between sleep disorders and neuropsychiatric symptoms. However, some of them remain unexplored. The described knowledge can be applied to further study the possibility of influencing neuropsychiatric symptoms through the correction of sleep disorders in patients with different stages of Parkinson's disease.

Current Update on Clinically Relevant Sleep Issues in Parkinson's Disease: A Narrative Review

Sleep disturbances are among the common nonmotor symptoms in patients with Parkinson’s disease (PD). Sleep can be disrupted by nocturnal motor and nonmotor symptoms and other comorbid sleep disorders. Rapid eye movement sleep behavior disorder (RBD) causes sleep-related injury, has important clinical implications as a harbinger of PD and predicts a progressive clinical phenotype. Restless legs syndrome (RLS) and its related symptoms can impair sleep initiation. Excessive daytime sleepiness (EDS) is a refractory problem affecting patients’ daytime activities. In particular, during the COVID-19 era, special attention should be paid to monitoring sleep problems, as infection-prevention procedures for COVID-19 can affect patients’ motor symptoms, psychiatric symptoms and sleep. Therefore, screening for and managing sleep problems is important in clinical practice, and the maintenance of good sleep conditions may improve the quality of life of PD patients. This narrative review focused on the literature published in the past 10 years, providing a current update of various sleep disturbances in PD patients and their management, including RBD, RLS, EDS, sleep apnea and circadian abnormalities.

A case-control study investigating food addiction in Parkinson patients

Eating disorders (EDs) in patients with Parkinson’s disease (PD) are mainly described through impulse control disorders but represent one end of the spectrum of food addiction (FA). Although not formally recognized by DSM-5, FA is well described in the literature on animal models and humans, but data on prevalence and risk factors compared with healthy controls (HCs) are lacking. We conducted a cross-sectional study including 200 patients with PD and 200 age- and gender-matched HCs. Characteristics including clinical data (features of PD/current medication) were collected. FA was rated using DSM-5 criteria and the Questionnaire on Eating and Weight Patterns-Revised (QEWP-R). Patients with PD had more EDs compared to HCs (27.0% vs. 13.0%, respectively, p < 0.001). They mainly had FA (24.5% vs. 12.0%, p = 0.001) and night eating syndrome (7.0% vs. 2.5% p = 0.03). In PD patients, FA was associated with female gender (p = 0.04) and impulsivity (higher attentional non-planning factor) but not with the dose or class of dopaminergic therapy. Vigilance is necessary, especially for PD women and in patients with specific impulsive personality traits. Counterintuitively, agonist dopaminergic treatment should not be used as an indication for screening FA in patients with PD.

Impulse control disorders and related behaviors in Parkinson's disease: risk factors, clinical and genetic aspects, and management

PURPOSE OF REVIEW

To review recent findings and research directions on impulse control disorders and related behaviors (ICDRBs) in Parkinson's disease (PD).

RECENT FINDINGS

Longitudinal studies found that prevalence increases during PD progression, incident ICDRBs being around 10% per year in patients treated with dopaminergic therapies. Screening tools and severity scales already developed have been validated and are available in several countries and languages. The main clinical risk factors include young age, male gender, type, doses and duration of dopaminergic therapy, PD motor severity and dyskinesia, depression, anxiety, apathy, sleep disorders, and impulsivity traits. Genetic factors are suspected by a high estimated heritability, but individual genes and variants remain to be replicated. Management of ICDRBs is centered on dopamine agonist decrease, with the risk to develop withdrawal symptoms. Cognitive behavioral therapy and subthalamic nucleus deep brain stimulation also improve ICDRBs. In the perspective of precision medicine, new individual prediction models of these disorders have been proposed, but they need further independent replication.

SUMMARY

Regular monitoring of ICDRB during the course of PD is needed, particularly in the subject at high risk of developing these complications. Precision medicine will require the appropriate use of machine learning to be reached in the clinical setting.

The urge to move: From restless legs syndrome to impulse control disorders in Parkinson's disease

Impulse control disorders (ICDs) in Parkinson's disease (PD) are defined as a failure to resist an "urge" to behave in a way that may be debilitating for oneself or others. The suggested immobilization test (SIT) has been developed to assess the "urge" to move and support the diagnosis of restless legs syndrome (RLS) in the general population and in PD. A clinical association between RLS and ICDs has been shown in PD and in the general population. We hypothesized that there could be a semiological overlap between RLS and ICDs, and conducted SIT in PD patients with and without ICDs. Fifty PD patients with (n = 17) and without (n = 33) current ICDs were included. SIT, videopolysomnography, demographical treatment, and motor, psycho-behavioural and sleep characteristics, including RLS, were recorded. PD patients with ICDs reported increased subjective discomfort during SIT (SD-SIT) compared to those without ICDs (p = .024). Multivariable analysis confirmed ICDs as an independent factor associated with increased SD-SIT in PD, regardless of the presence of RLS, PD severity and dopamine agonist treatment dose. The discomfort measured by SIT might not only reflect the "urge" to move in RLS but also the ICDs in PD, suggesting that ICDs and RLS in PD could share a common phenomenology.

Impulse Control Disorders and Dopamine-Related Creativity: Pathogenesis and Mechanism, Short Review, and Hypothesis

Impulse control disorder (ICD), including pathological gambling, hypersexuality, and compulsive shopping has been linked to antiparkinsonian medication, especially dopamine agonists. The mechanism of ICD is not completely clear, but it seems that ICD is the result of an activation of dopamine receptors, mostly D3 in the ventral striatum. Patients treated with dopamine agonists that have preferential affinity for D3 (including ropinirole and pramipexole) are much more prone to develop ICD. In addition, a genetic component is probably present, especially in young patients. Finally, environment and lifestyle may also play a role: those patients engaged in physical, social, and artistic activities are probably less likely to develop ICD compared to those patients with poor physical activity living in isolated environments.

Sleep in Parkinson's Disease with Impulse Control Disorder

PURPOSE OF REVIEW

This paper aims to explore the relationship between impulse-control disorders (ICDs) and sleep problems in patients with Parkinson's disease (PD) among scientific literature.

RECENT FINDINGS

Previously published results are controversial and sometimes inconclusive. ICDs and sleep disruption represent important non-motor features of Parkinson's disease, responsible for reducing quality of life and increasing burden of disease. The relationship between sleep problems and ICDs is complex and bidirectional. Indeed, sleep disturbances and fragmentation may play a crucial role in increasing susceptibility to impulsive behavior and may represent a risk factor for developing ICDs in PD patients. Moreover, REM sleep behavior disorder (RBD) and restless legs syndrome (RLS) have been indicated as independent risk factors for ICDs in PD patients. On the other hand, also ICDs may lead to sleep restriction and fragmentation, suggesting a bidirectional relationship. The association between sleep problems and ICDs in PD is far from being completely understood. Further studies are needed to confirm the nature of this relationship and its pathophysiology.

Impulse control disorders in Parkinson's disease

Impulse control disorders (ICD) are frequent side effects of dopamine replacement therapy (DRT) used in Parkinson's disease (PD) with devastating consequences on the patients and caregivers. ICD are behavioural addictions including compulsive gambling, shopping, sexual behaviour, and binge eating that are mainly associated with dopamine D2/D3 agonists. Their management is a real clinical challenge due to the lack of therapeutic alternative. Clinical studies have identified demographic and clinical risk factors for ICD such as younger age at disease onset, male gender, prior history of depression or substance abuse, REM sleep behaviour disorders and higher rate of dyskinesia. PD patients with ICD may also have a specific pattern of dopaminergic denervation in the ventral striatum. Specific evaluation tools have now been designed to better evaluate the severity and impact of ICD in PD. Patients with ICD display altered processing of reward and loss, and decisional bias associated with altered activity in cortical and subcortical areas such as the orbitofrontal cortex, amygdala, insula, anterior cingular cortex, and ventral striatum. Preclinical studies have demonstrated that D2/D3 agonists induce impairments in behavioural processes likely relevant to ICD such as risk-taking behaviour, preference for uncertainty, perseverative responding and sustained drive to engage in gambling-like behaviour. Whether interactions between dopamine denervation and DRT significantly contribute to the pathogenesis of ICD remains poorly understood so far, although features unique to PD have been identified in patients with ICD. Large-scale longitudinal studies are needed to better identify subjects with increased risk to develop ICD and develop therapeutic options.