Probable RBD Associates with the Development of RLS in Parkinson's Disease: A Cross-Sectional Study

Sleep related injury and its correlates in isolated rapid eye movement sleep behavior disorder

OBJECTIVES

To evaluate factors associated with sleep related injury (SRI) and persistent SRI (pSRI) in patients with isolated rapid eye movement sleep behavior disorder (iRBD).

METHODS

This is a retrospective cohort study. A total of 388 patients with iRBD were involved for a comprehensive review of sleep related injuries. SRI is defined as a lifetime history of injurious behaviors to self and/or bed partner, and pSRI is considered if injurious symptoms continued to occur frequently (≥1/month). Correlations of SRI/pSRI with clinical, lifestyle and polysomnographic characteristics were analyzed.

RESULTS

Lifetime SRI was reported in 322 (83 %) patients (66.3 ± 8.5 years old, male 77.0 %), with 19.3 % having severe injuries, including fractures (2.5 %) and subdural hemorrhage (1.2 %), while 7.5 % required medical attendance. SRI was related to more severe depressive features (Padj = 0.017), current alcohol drinking (Padj = 0.014) and higher mentalis phasic and tonic EMG activity (Padj = 0.042 and 0.048). After a mean follow-up of 5.1 years, 18.2 % of SRI patients (38/209) had pSRI despite intense treatment. Frequent nightmare at baseline (OR [95 % CI] = 1.43 [1.01, 2.03]), restless leg syndrome (OR [95 % CI] = 5.68 [1.42, 22.64]) and adult-onset sleepwalking (OR [95 % CI] = 2.52 [1.10, 5.76]) were associated with an increased risk of pSRI.

CONCLUSIONS

SRI is common in patients with iRBD and 18 % had pSRI despite intensive treatment, emphasizing the importance of bedside safety. The identification of risk factors for SRI and pSRI underscores the need for systematic clinical screening and targeted interventions for at-risk patients.

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.

Sleep Disorders and Cognitive Dysfunctions in Parkinson's Disease: A Meta-Analytic Study

A relationship between sleep disorders and cognitive dysfunctions was reported in Parkinson's Disease (PD), however, some studies did not confirm the link. A meta-analytic study was performed to investigate the relationship between sleep disorders and cognitive dysfunctions, and to clarify the evolution of cognitive status in PD patients with sleep disorders.The systematic literature search was performed up to November 2020 using PubMed, Scopus, and PsycINFO databases. We included studies published in peer-reviewed journals in English providing results about neuropsychological comparison between patients with or without sleep disorders. Meta-analysis on cross-sectional data included 54 studies for REM Sleep Behavior Disorder (RBD), 22 for Excessive Daytime Sleepiness (EDS), 7 for Obstructive Sleep Apnea (OSA), 13 for Restless Legs Syndrome (RLS), and 5 for insomnia, the meta-analysis on longitudinal data included 7 studies.RBD was related to deficits of global cognitive functioning, memory, executive functions, attention/working memory, language, and visuospatial abilities. EDS was associated with deficits of global cognitive functioning and attention and working memory abilities, whereas RLS and OSA were related to global cognitive dysfunction. Moreover, we revealed that PD patients with RBD and those with EDS performed worse than PD patients without sleep disorders at follow-up rather than baseline evaluation. Our results suggest that sleep disorders are associated with cognitive deficits supporting indirectly that these, especially the REM Sleep Behavior Disorder, reflect abnormalities of frontal networks and posterior cortical areas. Sleep disorders in patients with PD seem to also increase the risk for long-term cognitive decline.

Increased rapid eye movement density in Chinese patients with Parkinson's disease and RBD

OBJECTIVE

Impaired rapid eye movement sleep is common among patients with Parkinson's disease (PD). However, information on rapid eye movement density (REM) among PD patients is currently lacking. The current study sought to characterize REM density in PD patients and to examine the associations between REM density sleep parameters and clinical manifestations.

PARTICIPANTS AND METHODS

We retrospectively recruited 172 PD patients. All participants were assessed with a two-night polysomnography, and REM density was calculated. Clinical assessments were completed in PD patients before polysomnography.

RESULTS

Rapid eye movement sleep behavior disorder (RBD) was observed in 93 patients (54.1%). The disease duration, UPDRS part III score, Hoehn and Yahr (H-Y) stage, and HAMA, HAMD, PDQ-39 scores, and REM density in the Parkinson's disease patients with rapid eye movement sleep behavior disorder (RBD) were significantly higher than in the patients without RBD (P < 0.05). However, NREM sleep stage 3 time (N3 time) and percentage of N3 time of total sleep time (N3%) were significantly lower in the RBD patients than in the patients without RBD (P < 0.05). The forward binary logistic regression model showed that REM density, UPDRS-III score, and N3 sleep time were associated with RBD in the PD patients.

CONCLUSIONS

Our results confirm the high prevalence of RBD in patients with PD. Increased REM density was the main risk factor of RBD.