Restless legs syndrome: a comprehensive overview on its epidemiology, risk factors, and treatment

Lifestyle factors associated with symptoms suggestive of restless legs syndrome in Korean adolescents

OBJECTIVE

Restless legs syndrome (RLS) is a common sleep disorder among adolescents. This study aimed to investigate the lifestyle factors and sleep disturbances associated with the symptoms suggestive of RLS in Korean adolescents.

METHODS

In this cross-sectional study, we investigated a total of 25,789 adolescents (mean age, 15.8 ± 1.7 years; male, 48.5 %). The presence of symptoms suggestive of RLS was assessed with a single question about RLS in the Global Sleep Assessment Questionnaire. We performed multiple logistic regression analysis to estimate the odds ratios (ORs) and 95 % confidence intervals (CIs) of lifestyle factors and sleep disturbances that were independently associated with adolescent RLS.

RESULTS

The prevalence of RLS-suggestive symptoms was 5.1 % among adolescents. After adjustment, lifestyle factors associated with symptoms suggestive of RLS were occasional alcohol consumption (OR, 1.245; 95 % CI, 1.006-1.540) and proneness to Internet addiction (OR, 1.027; 95 % CI, 1.021-1.033). Bedtime behaviors associated with RLS-suggestive symptoms were sleeping with a doll or pet (OR, 1.194; 95 % CI, 1.032-1.381) and sleeping with a TV or radio on (OR, 1.366; 95 % CI, 1.156-1.614). Male sex, frequent snoring and witnessed apnea, perceived sleep insufficiency, excessive daytime sleepiness were also associated with RLS-suggestive symptoms in adolescents.

CONCLUSIONS

Adolescents with symptoms suggestive of RLS were associated with different lifestyle factors compared to adults with RLS. Further research is needed to determine the clinical implications of lifestyle factors in adolescent RLS.

Insomnia

Sleep significantly impacts health. Insomnia, characterized by difficulty with sleep onset, maintenance, and subsequent daytime symptoms, is increasingly prevalent and increases the risk of other medical comorbidities. The pathophysiology involves hyperarousal during non-REM sleep and altered sleep homeostasis. The 3P model explains the development and persistence of insomnia. Assessment is primarily clinical and based on appropriate history while distinguishing from other sleep disorders. "Somnomics" suggests a personalized approach to management. Cognitive behavioral therapy for insomnia is the first-line treatment in addition to other nonpharmacological strategies. Medications are a secondary option with weak supporting evidence.

A comprehensive update on the ADMET considerations for α2δ calcium channel ligand medications for treating restless legs syndrome

INTRODUCTION

Restless legs syndrome/Willis-Ekbom disease (RLS/WED) is a sleep-related sensory-motor disorder associated with poor sleep quality and impaired daily functioning. In patients affected by chronic RLS/WED, a pharmacological therapy is recommended. International guidelines suggest to start the treatment with a α2δ calcium channel ligand in most cases, unless contraindicated.

AREAS COVERED

The present review is based on an extensive Internet and PubMed search from 1986 to 2024. Our purpose is to describe the absorption, distribution, metabolism, and toxicology (ADMET) of the α2δ ligands, with common consideration for the therapeutic class, specificities of different compounds, efficacy, and safety in relation to other treatment options.

EXPERT OPINION

α2δ ligands are quite similar in their ADMET profiles, sharing most of the pharmacokinetics and potential adverse effects. However, we highlight the linear kinetic of gabapentin enacarbil and pregabalin, differently from gabapentin. α2δ ligands are safe and effective for the treatment of RLS/WED. Additional benefits can be obtained in comorbid insomnia, chronic pain syndromes, history of impulse control disorder, and comorbid anxiety. The use of α2δ ligands is associated with poor risk of augmentation. We still need new long-term safe and effective treatments, which could be developed along with our knowledge of RLS/WED pathophysiology.

Sex-specific patterns of discomfort in patients with restless legs syndrome

STUDY OBJECTIVES

Sex differences in the prevalence of restless legs syndrome (RLS) have been reported, with a higher prevalence in women than in men. However, sex differences in clinical presentation remain unclear. We aimed to investigate the phenotypic differences in patients with RLS between sexes by comparing clinical presentations, iron status, polysomnographic parameters, and treatment.

METHODS

We retrospectively evaluated 614 patients (225 men, 389 women) diagnosed with RLS. To enhance the robustness of the study, an age-matched control group of 179 men and 286 women without sleep disorders was also included. Information on demographics and sleep-related questionnaires were collected. Iron status was evaluated using blood samples, and polysomnography was performed to evaluate periodic leg movements and comorbid sleep disorders.

RESULTS

Our analysis revealed no sex difference in the severity of RLS but a difference in the pattern of symptoms. Women had more frequent symptoms of pain and awakening during sleep, while men had more common motor symptoms (both self-reported symptoms and periodic leg movement on polysomnography). Women with RLS also had lower iron parameters and received more frequent iron supplementation therapy than men. In contrast to women with RLS, who presented higher sleep disturbances and depressive mood, men with RLS had a higher risk of comorbidities such as hypertension and cardiovascular disease. These sex differences were notably more pronounced than in the control group.

CONCLUSIONS

This study suggests that sex differences exist in RLS phenotypes, and clinicians should consider these differences for treatment.

CITATION

Kim J, Kim JR, Park HR, Joo EY. Sex-specific patterns of discomfort in patients with restless legs syndrome. J Clin Sleep Med. 2024;20(2):253-259.

Prevalence and factors associated with restless legs syndrome among pregnant women in middle-income countries: a systematic review and meta-analysis

Introduction

Restless legs syndrome (RLS) is a debilitating condition characterized by uncomfortable sensations in the legs, typically occurring during periods of rest or sleep. It is more prevalent during pregnancy and is linked to sleep disturbances, diminished quality of life, and pregnancy complications. However, previous studies yielded inconsistent findings among pregnant women in middle-income countries. Consequently, this systematic review and meta-analysis sought to determine the pooled prevalence of restless legs syndrome and its associated factors in these populations.

Method

A systematic review and meta-analysis was conducted on published studies from middle-income countries until May 2023. The review strictly adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Relevant search terms were used to search for studies in PubMed, MEDLINE, EMBASE, and Google Scholar. Data extraction was performed using the Joanna Briggs Institute tool for prevalence studies. The meta-analysis was conducted using STATA 17 software, and heterogeneity was assessed using the I2 test, while publication bias was evaluated using Egger's test. Forest plots were also used to present the pooled prevalence and odds ratio (OR) with a 95% confidence interval (CI) using the random-effects model.

Result

This review included 22 studies from nine countries with a total of 17, 580 study participants. The overall pooled prevalence of RLS among pregnant women in middle-income countries was 13.82% (95% CI: 13.31, 14.32), and having low hemoglobin level (AOR: 1.68, 95% CI: 1.29, 2.18), history of RLS (AOR: 7.54, 95% CI: 3.02, 18.79), muscle cramps (AOR: 3.58, 95% CI: 1.21, 10.61), excessive day time sleepiness (AOR: 4.02, 95% CI: 1.34, 12.04), preeclampsia (AOR: 2.06, 95% CI: 1.28, 3.30), and taking prophylactic iron supplementation (AOR: 0.59, 95% CI: 0.50, 0.69) were the identified factors associated with it.

Conclusion

Generally, nearly one in every eight pregnant women in middle-income countries develop restless legs syndrome during pregnancy. Having low hemoglobin level, a history of RLS, muscle cramps, excessive daytime sleepiness, preeclampsia, and taking prophylactic iron supplementation were the identified factors associated with it. These findings underscore the importance of addressing the identified factors associated with RLS in order to effectively mitigate its occurrence among pregnant women.

Comparative assessment of choroidal thickness and choroidal vascularity index in patients with restless legs syndrome

BACKGROUND

Increased sympathetic activity has been emphasized in the pathophysiology of restless legs syndrome (RLS). This study aims to evaluate the choroidal thickness (CT) and choroidal vascularity index (CVI) values of individuals with RLS.

METHODS

A total of 60 volunteers, 30 individuals with RLS and 30 healthy individuals, were included in the study. The central macular thickness, subfoveal CT, and the CTs 1000 μm away from the fovea in the temporal and nasal regions were measured by optical coherence tomography. Total choroidal area (TCA), luminal area (LA) and stromal area (SA) were calculated using the binarization method. CVI was calculated as the ratio of lumen area to total choroidal area (LA/TCA).

RESULTS

There was no significant difference between the participants in terms of age, gender, spherical equivalent, intraocular pressure, and axial length (p>0.05). The mean LA/SA was 1.56%±0.05 in RLS group and 1.99%±0.28 in the control group. The mean CVI was 0.64%±0.02% in RLS group and 0.66%±0.03 in the control group. There was no significant difference between the groups in terms of CT, TCA and LA values. There were significant differences between the groups in SA, LA/SA and CVI values (p = 0.017, p<0.001, and p = 0.004, respectively).

CONCLUSION

SA values were significantly higher in RLS group than in control group. The LA/SA and CVI values were significantly lower in RLS group than in control group. These findings suggests that there is vascular narrowing due to sympathetic overactivity in RLS patients.

Restless leg syndrome in multiple sclerosis: a case-control study

Objectives

This study assessed the prevalence of restless leg syndrome (RLS) among patients with multiple sclerosis (pwMS) and the association between RLS and MS disease duration, sleep disturbance, and daytime fatigue.

Methods

In this cross-sectional study, we interviewed 123 patients via phone calls using preset questionnaires containing the International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria, Pittsburgh Sleep Quality Index (PSQI), and Fatigue Severity Scale (FSS) diagnostic criteria validated in both Arabic and English. The prevalence of RLS in MS was compared to a group of healthy controls.

Results

The prevalence of RLS in pwMS, defined by meeting all four requirements included in the IRLSSG diagnostic criteria, was 30.3% compared to 8.3% in the control group. About 27.3% had mild RLS, 36.4% presented with moderate, and the remaining had severe or very severe symptoms. Patients with MS who experience RLS had a 2.8 times higher risk of fatigue compared to pwMS without RLS. pwMS with RLS had worse sleep quality, with a mean difference of 0.64 in the global PSQI score. Sleep disturbance and latency had the most significant impact on sleep quality.

Conclusion

The prevalence of RLS among MS patients was significantly higher compared to the control group. We recommend educating neurologists and general physicians to increase their awareness of the increasing prevalence of RLS and its association with fatigue and sleep disturbance in patients with MS.

Alterations of the thalamic nuclei volumes and intrinsic thalamic network in patients with restless legs syndrome

We aimed to investigate the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with primary restless legs syndrome (RLS) compared to healthy controls. Seventy-one patients with primary RLS and 55 healthy controls were recruited. They underwent brain MRI using a three-tesla MRI scanner, including three-dimensional T1-weighted images. The intrinsic thalamic network was determined using graph theoretical analysis. The right and left whole thalamic volumes, and the right pulvinar inferior, left ventral posterolateral, left medial ventral, and left pulvinar inferior nuclei volumes in the patients with RLS were lower than those in healthy controls (0.433 vs. 0.447%, p = 0.034; 0.482 vs. 0.502%, p = 0.016; 0.013 vs. 0.015%, p = 0.031; 0.062 vs. 0.065%, p = 0.035; 0.001 vs. 0.001%, p = 0.034; 0.018 vs. 0.020%, p = 0.043; respectively). There was also a difference in the intrinsic thalamic network between the groups. The assortative coefficient in patients with RLS was higher than that in healthy controls (0.0318 vs. - 0.0358, p = 0.048). We demonstrated the alterations of thalamic nuclei volumes and intrinsic thalamic network in patients with RLS compared to healthy controls. These changes might be related to RLS pathophysiology and suggest the pivotal role of the thalamus in RLS symptoms.

Evaluation of Serum Selenium Level, Quality of Sleep, and Life in Pregnant Women With Restless Legs Syndrome

Restless legs syndrome (RLS) is a multifactorial disease that patients describe as restlessness in their legs, which creates a desire to move their legs, especially in the evening and at rest. This study aims to investigate serum selenium levels in RLS and document the quality of sleep and life in pregnant women with RLS according to International Restless Legs Syndrome Study Group (IRLSSG) diagnostic criteria. Thirty-eight moderate to severe RLS patients with pregnancy at 38-41 weeks of gestation were determined as the case group, and 38 women with healthy gestational age-matched pregnancies were determined as the control group. Maternal serum selenium levels were compared between the RLS case group and the group of healthy pregnant women at the time of hospitalization for delivery. The Pittsburgh Sleep Quality Index (PSQI) and The Quality of Life Scale (SF-36) were applied to the patients. The mean selenium level (µg/L) was statistically significantly lower in the RLS group (53.24 ± 10.28), compared to the healthy pregnant population (58.95 ± 11.29) (P = 0.024). The PSQI score was significantly higher in the RLS case group (P = 0.033). Especially sleep efficiency (P = 0.018) and daytime dysfunction (P = 0.032) sub-parameters were affected. The SF-36 questionnaire was examined and a significant difference was detected between the two groups in role emotional (P = 0.026), social functioning (P = 0.023), and body pain (P = 0.044) sub-parameters. Serum selenium level was significantly lower, the sleep quality of the RLS group was impaired and their quality of life was affected in pregnant women with RLS. Further studies are needed to determine whether selenium replacement in pregnant women with RLS is feasible or not.

Restless Legs Syndrome and Periodic Limb Movements of Sleep: From Neurophysiology to Clinical Practice

SUMMARY

This article summarizes restless legs syndrome (RLS), periodic limb movements of sleep, and periodic limb movement disorder. RLS is a common sleep disorder with a prevalence of 5% to 15% in the general population. RLS can present in childhood, and incidence increases with age. RLS can be idiopathic or secondary to iron deficiency, chronic renal failure, peripheral neuropathy, and medications such as antidepressants (with higher rates for mirtazapine and venlafaxine, while bupropion may reduce symptoms at least in the short term), dopamine antagonists (neuroleptic antipsychotic agents and antinausea medications), and possibly antihistamines. Management includes pharmacologic agents (dopaminergic agents, alpha-2 delta calcium channel ligands, opioids, benzodiazepines) and nonpharmacologic therapies (iron supplementation, behavioral management). Periodic limb movements of sleep are an electrophysiologic finding commonly accompanying RLS. On the other hand, most individuals with periodic limb movements of sleep do not have RLS. The clinical significance of the movements has been argued. Periodic limb movement disorder is a distinct sleep disorder that arises in individuals without RLS and is a diagnosis of exclusion.

Sleep-related motor disorders

Sleep-related motor disorders include non-rapid-eye movement (NREM) sleep parasomnias, rapid-eye movement (REM), sleep parasomnias including REM sleep behavior disorder (RBD), isolated motor phenomena in sleep, and periodic limb movement disorder. Restless legs syndrome (RLS) occurs while awake but is closely related to sleep and has a circadian pattern. The pontine sublaterodorsal tegmental nucleus has an important role in aligning motor control with sleep states, and dysfunction in this region can explain motor activities including cataplexy and loss of REM atonia seen in REM sleep behavior disorder. This chapter begins with a review of motor control in sleep. The rest of the chapter summarizes the clinical presentation, epidemiology, differential and treatment of NREM, REM, and isolated sleep-related motor disorders as well as restless legs syndrome.

A Narrative Review of the Lesser Known Medications for Treatment of Restless Legs Syndrome and Pathogenetic Implications for Their Use

Background

There are several well-known treatments for Restless Legs Syndrome (RLS), including dopamine agonists (pramipexole, ropinirole, rotigotine), anticonvulsants (gabapentin and its analogs, pregabalin), oral or intravenous iron, opioids and benzodiazepines. However, in clinical practice, treatment is sometimes limited due to incomplete response or side effects and it is necessary to be aware of other treatment options for RLS, which is the purpose of this review.

Methods

We performed a narrative review detailing all of the lesser known pharmacological treatment literature on RLS. The review purposefully excludes well-established, well-known treatments for RLS which are widely accepted as treatments for RLS in evidence-based reviews. We also have emphasized the pathogenetic implications for RLS of the successful use of these lesser known agents.

Results

Alternative pharmacological agents include clonidine which reduces adrenergic transmission, adenosinergic agents such as dipyridamole, glutamate AMPA receptor blocking agents such as perampanel, glutamate NMDA receptor blocking agents such as amantadine and ketamine, various anticonvulsants (carbamazepine/oxcarbazepine, lamotrigine, topiramate, valproic acid, levetiracetam), anti-inflammatory agents such as steroids, as well as cannabis. Bupropion is also a good choice for the treatment of co-existent depression in RLS because of its pro-dopaminergic properties.

Discussion

Clinicians should first follow evidence-based review recommendations for the treatment of RLS but when the clinical response is either incomplete or side effects are intolerable other options can be considered. We neither recommend nor discourage the use of these options, but leave it up to the clinician to make their own choices based upon the benefit and side effect profiles of each medication.

Summary

Clinicians should first follow evidence-based reviews for RLS but when response is incomplete and side effects intolerable, other medications can be considered. We do not make a recommendation on these options but leave it up to the clinician to make their own choice based upon the benefit and side effect profiles of each medication.

Restless Legs Syndrome and the Use of Antipsychotic Medication: An Updated Literature Review

Restless legs syndrome or Willis-Ekbom disease (RLS/WED) is a sleep-related movement disorder characterized by an urge to move the legs. This impulse is usually accompanied by an uncomfortable and unpleasant sensation in the legs, which worsens at night and during periods of inactivity and is relieved by movement. Several studies in the literature reported the association between RLS and different antipsychotic medications. with Olanzapine, Quetiapine, and Clozapine identified as the most common causes. The literature suggests that the development of RLS in antipsychotic users may be attributed to the inhibition of dopaminergic neurotransmission or the impact of antipsychotics on iron metabolism. Diagnosing antipsychotic-induced RLS remains a substantial challenge in clinical practice, with challenges in the management of this condition also being widely reported in the current literature. In this article, we will review the evidence suggesting the association between RLS and the use of antipsychotic medications, differentiate between RLS and other movement disorders, and give a brief review of the pathophysiology, diagnosis, and management of RLS and its challenges among psychotic patients.

Overlapping features of restless legs syndrome and growing pains in Turkish children and adolescents

BACKGROUND

Restless legs syndrome (RLS) and growing pains (GPs) share many common features and are sometimes overlapping diagnoses. The present study aims to investigate the shared features of patients with RLS, classified based on the 2013 diagnostic criteria of International Restless Legs Syndrome Study group and of patients with GPs, diagnosed based on the combined criteria proposed in 2013.

METHODS

A cross-sectional population study was conducted in 7 Istanbul schools, which were selected randomly. A total of 4565 (56.1% female) children aged 9 to 18 years were included. In the first stage, candidates of RLS and GPs were identified based on 2 separate questionnaires, whose diagnoses were confirmed by a second survey applied to them under parental supervision.

RESULTS

Out of 192 children (65.6% female) diagnosed as definite RLS (yearly prevalence: 4.2%), 30 (15.6%) reported bilateral leg muscle pain localized typical regions for GPs, which started <13 years of age in 17 children. An urge to move the legs to relieve unpleasant sensations or pain was present in 39.3% of 140 children (64.3% female) classified as GPs (yearly prevalence: 3.1%). Occurrence of symptoms at rest or when lying down was present in 36.4% of GPs children and relief by gross movements was in 21.4% children. Only 12 patients (9 with definite RLS and 3 with GPs) (0.03% of total cohort) were eligible for overlapping diagnosis of GPs and RLS.

CONCLUSION

Although a considerable number of patients with RLS and GPs share some clinical features, a combined phenotype is very rare.

Chronic inflammation markers and cytokine-specific autoantibodies in Danish blood donors with restless legs syndrome

Restless Legs Syndrome (RLS) is a neurological sensorimotor disorder negatively impacting sufferers’ quality of sleep and health-related quality of life. The pathophysiology of RLS is poorly understood and research focusing on the link between RLS and inflammation has been limited. Our study aimed to investigate whether chronic inflammation markers C-reactive protein (CRP) and soluble urokinase-type plasminogen activator receptor (suPAR), as well plasma levels of five different cytokine-specific autoantibodies (c-aAb), i.e. modulators of inflammation, associate with RLS in otherwise healthy individuals. CRP, suPAR and c-aAb were measured in plasma samples of participants from the Danish Blood Donor Study in 2010. Returning donors between 2015 and 2018 completed the validated Cambridge-Hopkins RLS-questionnaire for RLS assessment, resulting in datasets with RLS assessment and values for CRP (N = 3564), suPAR (N = 2546) and c-aAb (N = 1478). We performed logistic regression models using the CRP, suPAR or c-aAb as the independent variable and RLS status as the dependent variable, adjusted for appropriate covariates. Our study indicates that a high concentration of CRP is associated with RLS, while an increased probability of experiencing frequent RLS symptoms in those with an elevated plasma suPAR level appears to be mediated through lifestyle factors. We additionally report that a high titer of autoantibodies specific against the cytokine interferon-alpha was associated with RLS. Our results support the existence of links between systemic inflammation and RLS, though further RLS studies on CRP, suPAR and c-aAb in larger cohorts are warranted to confirm our findings and further reveal the hitherto underexplored links between RLS and inflammation.

Investigating the inflammation marker neutrophil-to-lymphocyte ratio in Danish blood donors with restless legs syndrome

Background

Restless Legs Syndrome (RLS) is a neurological sensorimotor disorder that occurs in the evening and night, thereby impacting quality of sleep in sufferers. The pathophysiology of RLS is poorly understood but inflammation has been proposed as possibly being involved. The neutrophil-to-lymphocyte ratio (NLR) can be used as an inflammation marker but results from small studies have been inconclusive in determining whether NLR is associated with RLS. We aimed to assess whether an association between NLR and RLS exists in a large cohort of healthy individuals.

Methods

Neutrophils and lymphocytes were measured in blood samples of 13,055 individuals from the Danish Blood Donor Study, all of whom completed the validated Cambridge-Hopkins RLS-questionnaire for RLS assessment.

Results

In the sample, 661 individuals were determined as current RLS cases (5.1%). A higher proportion of individuals with RLS were females (62.5% vs 47.5%; P<0.001) and RLS cases were older than controls (P<0.001), but no differences in body mass index (BMI), smoking or alcohol consumption were found between the two groups. An increased NLR was observed in RLS cases compared to controls (median NLR: 1.80 vs 1.72; P = 0.033). In an unadjusted logistic regression model, increased NLR was associated with RLS (OR = 1.10 per NLR unit increase [95%CI:1.01–1.20]; P = 0.032); however, the association was not significant in multivariate models adjusting for sex and age (P = 0.094) or sex, age, alcohol consumption, smoking status and BMI (P = 0.107).

Conclusion

We found no association between RLS and NLR among Danish blood donors after adjusting for sex, age, alcohol consumption, smoking status and BMI. Further studies are needed to determine whether inflammation is a risk factor for RLS.

Effectiveness and Safety of Botulinum Toxin Type A in Treatment of Restless Legs Syndrome: A Systematic Review and Meta-Analysis

Our study aimed to investigate the effectiveness and safety of botulinum toxin type A in patients with restless legs syndrome. We searched electronic databases, including PubMed, Cochrane Library, and Web of Science, up to 12 June 2021, for published articles. We enrolled randomized controlled clinical trials and non-randomized controlled studies involving patients with restless legs syndrome who were treated with botulinum toxin. Quality assessment was performed using the Cochrane risk of bias tool and Joanna Briggs Institute Critical Appraisal Checklist for Quasi-Experimental Studies. As for the results, we included four articles comprising 62 participants, two studies were randomized controlled trials. Improvement in International Restless Legs Syndrome Study Group (IRLSSG) rating scale was observed in three studies. Adverse events were temporary and self-limited. Meta-analyses were performed, including the two randomized controlled trials with 27 participants. Compared with placebo, botulinum toxin injection significantly reduced scores of IRLSSG rating scale (SMD, −0.819, 95% confidence interval [CI], −1.377 to −0.262). A total of 11.8% (95% CI, 0.7–72.4%) of patients reported at least one adverse event. In conclusion, botulinum toxin injection may relieve restless legs syndrome related symptoms. However, decisive conclusions cannot be drawn because of the small number of patients included in our meta-analysis. Large-scale, randomized controlled trials are warranted to discover the optimal dose, safety, and long-term effect of intervention with botulinum toxin type A for patients with restless legs syndrome.

No association between plasma hepcidin levels and restless legs syndrome - results from the Danish Blood Donor Study

BACKGROUND

Restless Legs Syndrome (RLS) is a neurological sensorimotor disorder that occurs in the evening and night, thereby often impacting quality of sleep in sufferers. The aetiology of RLS is not completely understood although iron dysregulation has been suggested as a likely pathway. The relationship between RLS and the iron regulatory protein hepcidin has not been studied in large cohorts. We aimed to assess whether an association between plasma hepcidin variation and RLS exists in a large cohort of healthy individuals.

METHODS

Plasma hepcidin levels were measured in 9708 Danish blood donors from the Danish Blood Donor Study all of whom correctly completed the validated Cambridge-Hopkins RLS-questionnaire for RLS assessment.

RESULTS

A total of 466 blood donors were determined as current RLS cases in the sample (4.8%). RLS cases had a significantly higher proportion of females (56.7% vs 46.7%; P < 0.001) and were older (median age [IQR] 40.6 years vs 38.0 years; P = 0.010) than controls. RLS cases were also more frequent smokers (P = 0.004). No significant differences were found in body mass index (BMI), alcohol consumption, time of donation and donation history between cases and controls. No difference in plasma hepcidin levels was observed between RLS cases and controls (median concentration [IQR]: 10.5 ng/ml [6.3-16.4] in RLS cases vs 10.5 ng/ml [6.0-16.5] in controls). Using a logistic regression model, we found that hepcidin levels were not associated with RLS after adjusting for age, sex, alcohol consumption, smoking status, donation time and donation history (OR = 1.00 [0.99-1.02] per 1 ng/ml increase of hepcidin; P = 0.429).

CONCLUSION

Our study in Danish blood donors did not find an association between RLS and plasma hepcidin levels. Our findings suggest that plasma hepcidin's role as a potential diagnostic biomarker of RLS is inadequate.

The translational neuroscience of sleep: A contextual framework

Sleep is entwined across many physiologic processes in the brain and periphery, thereby exerting tremendous influence on our well-being. Yet sleep exists in a social-environmental context. Contextualizing sleep health with respect to its determinants—from individual- to societal-level factors—would enable neuroscientists to more effectively translate sleep health into clinical practice. Key challenges and opportunities pertain to (i) recognizing and exploring sleep’s functional roles, (ii) clarifying causal mechanisms in relation to key outcomes, (iii) developing richer model systems, (iv) linking models to known contextual factors, and (v) leveraging advances in multisensory technology. Meeting these challenges and opportunities would help transcend disciplinary boundaries such that social-environmental considerations related to sleep would become an ever-greater presence in the clinic.

Clinical Decision-Making: Restless Legs Syndrome and Dementia in Older Adults

Restless legs syndrome (RLS), one of the more prevalent sleep disturbances among older adults, impacts quality of life. Patients with dementia are at high risk for developing RLS and may be unable to describe their symptoms. Often underdiagnosed, RLS can contribute to discomfort, pain, nighttime agitation, disturbed sleep, and falls. Clinical assessment is crucial and should include a thorough evaluation with input from the patient and family, deprescribing medication if possible, and consideration of common sleep-disturbing factors. Evidence-based treatment in this population is limited; overall focus should center on relieving discomfort while identifying and treating bothersome sleep symptoms.

How Common is Essential Tremor? Update on the Worldwide Prevalence of Essential Tremor

Background

Essential tremor (ET) is among the most prevalent movement disorders. Comprehensive reviews of disease prevalence were published in 1998 and 2010 but not since then. We reviewed the prevalence of ET in population-based epidemiological studies, derived a precise summary estimate of prevalence from these studies, and examined differences in prevalence across studies. We used two methods: a descriptive-analytical approach and a meta-analysis.

Methods

A PUBMED search yielded 14 published papers since the 2010 review.

Results

There were 42 population-based prevalence studies (23 countries and 6 continents). In a meta-analysis, pooled prevalence (all ages) = 1.33%, with statistically significant heterogeneity across studies (I2 = 99.3%, p < 0.0001). In additional descriptive analyses, median crude prevalence (all ages) = 0.4% and mean = 0.67%. Prevalence increased markedly with age, and especially with advanced age. In the meta-analysis, prevalence (age ≥ 65 years) = 5.79%, and in descriptive analyses, median crude prevalence (age ≥ 60-65) = 5.9% and mean = 8.0%. In the oldest age groups, median prevalence = 9.3%, with several studies reporting values >20%. The prevalence increased by 74% for every decade increase in age (p < 0.0001). Gender did not impact the prevalence of ET (p = 0.90).

Discussion

Precise prevalence estimates are important because they form the numerical basis for public health initiatives and offer clues about underlying biological factors of mechanistic importance. The prevalence of ET among those age ≥ 65 is similar to that reported for Alzheimer's disease in elders, suggesting that ET may be the most common neurodegenerative disease.

Challenges in the Treatment of Restless Legs Syndrome: A Case Report

Treatment resistant restless legs syndrome (RLS) in the setting of psychiatric comorbidities can be difficult to manage. Our patient is a 69-year-old Caucasian gentleman with bipolar disorder type I, unspecified anxiety disorder, obstructive sleep apnea (OSA), and treatment-refractory RLS. At initial presentation, the patient’s prescribed medication regimen included fluoxetine 40 mg daily, gabapentin 800 mg in the morning and 3200 mg at bedtime, pramipexole 0.375 mg daily, lamotrigine 200 mg daily, trazodone 200 mg at bedtime, and temazepam 15 to 30 mg as needed for insomnia and RLS. Over the course of nearly 4 years, treatment interventions for this patient’s RLS included: cognitive behavioral therapy for insomnia, discontinuation of exacerbating medications, switching dopamine agonists, use of pregabalin and iron supplement. This report demonstrates a challenging case of RLS in the setting of psychiatric comorbidities, development of augmentation, and polypharmacy.

Suspected Agomelatine-induced restless legs syndrome: a case report

BACKGROUND

Restless Legs Syndrome (RLS) is a sensorimotor disorder characterized by unpleasant and distressing sensations in the lower limbs that are more pronounced in the evening, commence or worsen at rest, and show partial or complete relief following movement. It can occur as a primary disorder, secondary to medical conditions or treatment with medications including but not limited to antidepressants or antipsychotics.

CASE PRESENTATION

A 32-year old man with major depressive disorder showed partial response to Escitalopram 10 mg daily. Agomelatine 25 mg at night was added to Escitalopram to treat his residual depressive symptoms, namely insomnia and tiredness. Within two days he developed restlessness and unpleasant sensations in his legs which were worse at night. Symptom severity increased over the following days, prompting an urgent consultation a week later. The patient's presentation met the criteria for RLS. Agomelatine was discontinued leaving the patient on Escitalopram alone. The patient's symptoms improved within 24 h of stopping Agomelatine, with complete resolution four days later. There was no recurrence of RLS during follow-up. The patient scored 6 on Naranjo's adverse drug reaction probability scale, indicating a probable adverse drug reaction caused by Agomelatine.

CONCLUSIONS

To the best of our knowledge, this is the first case report of suspected Agomelatine-induced RLS. Clinicians need to be aware of RLS to enable prompt diagnosis and management. We suggest adding Agomelatine to the list of agents that can potentially induce RLS.

Prevalence of restless leg syndrome and effects on quality of life during pregnancy

PURPOSE

Restless leg syndrome (RLS) is a movement disorder which constitutes the most common and major risk group during pregnancy. The purpose of this study was to determine prevalence and severity of RLS during pregnancy and to investigate the effect of RLS on quality of life in pregnant women.

METHODS

This cross-sectional study was conducted in antenatal clinics of four different public hospitals. Data collected were pregnancy assessment form, RLS diagnostic criteria form, RLS severity scale, and SF-12 quality of life scale.

RESULTS

Among 718 pregnant women, mean age was 28.3±5.9 years (range 19 to 45). According to the diagnostic criteria of RLS, RLS prevalence was 22% (n=159). Of the 159 women with RLS, 41% had moderate severity and 40% had severe RLS. Prevalence of RLS in pregnant women increased with gestational week, working time during pregnancy, weight before pregnancy, total weight gain during pregnancy, and pre-pregnancy body mass index. Physical health scores, physical functioning scores, pain scores, emotional role difficulty scores, and social function scores were significantly lower in the pregnant women with RLS than without RLS (p <0.05).

CONCLUSIONS

Approximately one-fifth of the pregnant women had RLS, mostly in the third trimester, and the severity of RLS was predominantly moderate and severe. Pregnant women with RLS had poorer quality of life than pregnant women without RLS.

Treating Restless Legs Syndrome Was Associated With Low Risk of Cardiovascular Disease: A Cohort Study With 3.4 Years of Follow-Up

Background Restless legs syndrome (RLS) is associated with higher cardiovascular disease (CVD) risk. However, it remains unknown whether treatment of RLS lowers the cardiovascular risk associated with RLS. Methods and Results All data were collected retrospectively, but subjects were prospectively followed forward in time to determine outcomes of interest. We used the Truven Health MarketScan Commercial Claims and Encounters database from January 1, 2006, through December 31, 2014. Participants were 169 393 individuals, which included 24 199 nonpregnant participants with an RLS diagnosis (16 694 receiving treatments for RLS and 7505 without treatment) during 2006 to 2008 and 145 194 age- and sex-matched participants without RLS. All participants were free of CVD before January 1, 2009 (analysis baseline). Incident CVD cases (myocardial infarction, angina, stroke, atrial fibrillation, and heart failure) were identified. We adjusted for potential confounders, such as presence of chronic conditions and medication use. We identified 16 574 incident CVD cases during 2009 to 2014. Relative to the non-RLS group, the adjusted hazard ratio (HR) for future CVD was 1.26 (95% CI, 1.20-1.32) (P<0.001) for the RLS with treatment group, and 1.53 (95% CI, 1.42-1.65) (P<0.001) for the RLS without treatment group. Significant lower CVD risk was observed for all different RLS treatments, including dopaminergics, anticonvulsants, benzodiazepines, and opiates (adjusted HRs range, 0.71-0.84; P<0.001 for all), except for ergot-dopamine use. Conclusions RLS was associated with higher future CVD risk. However, RLS was associated with statistically significantly less future cardiovascular risk in RLS patients with treatment than in those without treatment.

Large genome-wide association study identifies three novel risk variants for restless legs syndrome

Restless legs syndrome (RLS) is a common neurological sensorimotor disorder often described as an unpleasant sensation associated with an urge to move the legs. Here we report findings from a meta-analysis of genome-wide association studies of RLS including 480,982 Caucasians (cases = 10,257) and a follow up sample of 24,977 (cases = 6,651). We confirm 19 of the 20 previously reported RLS sequence variants at 19 loci and report three novel RLS associations; rs112716420-G (OR = 1.25, P = 1.5 × 10-18), rs10068599-T (OR = 1.09, P = 6.9 × 10-10) and rs10769894-A (OR = 0.90, P = 9.4 × 10-14). At four of the 22 RLS loci, cis-eQTL analysis indicates a causal impact on gene expression. Through polygenic risk score for RLS we extended prior epidemiological findings implicating obesity, smoking and high alcohol intake as risk factors for RLS. To improve our understanding, with the purpose of seeking better treatments, more genetics studies yielding deeper insights into the disease biology are needed.

[Restless legs syndrome in Parkinson's disease]

Disturbances in sleep and wakefulness are important symptoms of Parkinson's disease (PD) and are associated with negative effects on patients' quality of life. The analysis of literature on the relationship between RLS and PD revealed three main hypotheses explaining the relatively high incidence of RLS in PD: (1) RLS can be considered as an early (prodromal) manifestation or a predictor of PD that can outpace its main symptoms by several years (by analogy with conduct disorder during sleep with REM); (2) the high incidence of RLS in the advanced stage of PD may be associated with augmentation of previously latent RLS symptoms during prolonged dopaminergic therapy of PD; (3) a significant proportion of RLS cases in PD patients are not «classical» RLS, but represent, for example, manifestations of motor or non-motor fluctuations or a special form of stereotypy in the legs. Further research is needed to determine if any of these statements are true.

Sleep state instabilities in patients with periodic limb movements in sleep - Detection and quantification with heart rate variability

BACKGROUND

Restless legs syndrome (RLS) has been thought to increase the risk of hypertension, cardiovascular events, and all-cause mortality. Periodic limb movements in sleep (PLMS) can be observed in most patients with RLS. Using non-invasive physiologic measurement and analysis, including heart rate variability (HRV) analysis, we aimed to investigate sleep quality and sleep state stability.

METHOD

A total of 53 healthy controls and 15 patients with RLS and PLMS were recruited. Patients with other sleep-related disorders such as obstructive sleep apnea (OSA) and major depressive disorder (MDD) were excluded. Each subject was evaluated using sleep and mood questionnaires and had to undergo polysomnography (PSG). HRV analysis was applied to assess autonomic function and analyze correlations with the severity of periodic leg movements (PLM). The power of different brainwaves was analyzed using electroencephalogram (EEG). Electromyogram (EMG) was also used to explore the temporal correlation between changes in HRV and leg movement events.

RESULTS

Compared with healthy controls, PLMS group had not only poorer perceived sleep and mood questionnaires scales but also reductions in parasympathetic-related HRV indices and increases in sympathetic-related HRV parameters. The changes were in proportion to the severity of PLM. Brainwaves and sleep stage which indicate "deep sleep" decreased in the PLMS group. There were no significant temporal correlations between changes in HRV and leg movement events.

CONCLUSIONS

Our findings suggest that patients with RLS and PLMS have poorer subjective sleep and mood scales. Besides, objective sleep quality including HRV analysis and brainwaves analysis revealed reduced parasympathetic tone, increased sympathetic tone, and sleep disturbance, which reveal the possibility of a higher risk for secondary disease.

Survival in Restless Legs Syndrome: An 11-Year Surveillance, Community-Based Population Study

<b><i>Background:</i></b> A growing body of evidence relates restless legs syndrome (RLS) to an increased risk of mortality attributable to both cerebrovascular and cardiovascular events. The aim was to investigate survival in patients with RLS. <b><i>Methods:</i></b> This was an observational, retrospective longitudinal study of a cohort of patients followed up for 11 years. RLS was diagnosed by a physician using the International RLS Study Group criteria. Mortality was analyzed using age-standardized mortality ratios (SMR: observed/expected deaths) and Cox regression analysis. <b><i>Results:</i></b> Vital status was studied in a cohort of 232 patients: 181 women (78%), 96 with RLS (41.4%) with a mean age at baseline of 49.8 ± 15.0 years and a mean RLS duration of 14.1 ± 1.9 years, and 136 non-RLS (58.6%) with a mean age of 51.3 ± 14.9 years. This RLS cohort was followed up for a period of 10.4 ± 2.0 years. As of September 2019, 17 (7.3%) patients died (6 with RLS, 6.3%), and the most frequent cause was oncological (66.7%). A total of 944 person-years of observations were available for survival analysis. RLS was not associated with increased mortality in adjusted Cox regression analysis (HR = 1.12, 95% CI: 0.40–3.15), and survival was similar to that expected for the general population (SMR = 0.61, 95% CI: 0.27–1.36). <b><i>Conclusions:</i></b> RLS seems not to be associated with increased mortality compared to the general population. Still, studies with prospective data collection with large samples are needed to study the long-term mortality risk factors in RLS cohorts.

Investigation of chronic venous insufficiency in patients with sleep disorders due to restless legs syndrome

BACKGROUND

We aimed to investigate of chronic venous insufficiency on patients with sleep disorder due to restless legs syndrome.

METHOD

Five hundred forty-one cases on whom polysomnography was performed due to sleep disorder were evaluated retrospectively. Forty patients with restless legs syndrome were determined. They were examined by history, physical examination, and duplex ultrasonography in terms of chronic venous insufficiency. The sleep stage rates of both groups were compared (that the rate of total sleep time in polysomnography to sleep stages is expressed as minute and percentage has been defined as sleep stage rate).

RESULT

Chronic venous insufficiency was identified in 20 out of 40 patients (group 1; female, 90%). In group 2, there were patients with only restless legs syndrome but with no chronic venous insufficiency (female, 80%). The mean ages of both groups were 56.4 ± 11.8 and 54.3 ± 14.7 years. Stage 1 sleep rate in group 1 was 5% ± 2.7 and in group 2 was 8% ± 3.8 (p = 0.006). Periodic limb movement index (polysomnography finding evaluating involuntary leg movements during sleep) was 11.4 ± 17.5 in group 1, and it was 29.4 ± 37.9 in group 2 (p = 0.006).

CONCLUSION

We recommend that chronic venous insufficiency should be investigated in patients with primary restless legs syndrome diagnosis.

Treatment of restless legs syndrome with a pump; efficacy and complications

OBJECTIVES

Restless legs syndrome (RLS) has a prevalence of 2.5%-15% in the general population. For those who suffer from a medically refractory RLS, intrathecal morphine treatment has been shown to be effective. The aim of this retrospective study was to investigate efficacy, complications and side effects in patients treated over several years with an implantable pump. A comparison was done to a group of patients treated with a similar pump system due to spasticity.

MATERIALS AND METHODS

The charts of ten patients with severe or very severe RLS have been reviewed. These patients have received an intrathecal drug delivery system during 2000-2016. To compare the rate of complications, a control group of 20 patients treated with intrathecal baclofen due to spasticity was included in the study. Their time of treatment corresponded to the RLS patients.

RESULTS

The severity of symptoms related to RLS decreased significantly after treatment. Doses required ranged from 68 to 140 µg/d. Two cases of side effects were detected; one case with nausea and dizziness and one case with headache and fatigue. The rate of mechanical, infectious and other complications was similar between the two groups.

CONCLUSIONS

In light of the decrease in symptom severity and the low rate of side effects, intrathecal morphine can be considered an adequate treatment for those suffering from medically refractory RLS. The occurrence of complications did not differ between subjects with RLS and spasticity.

Restless legs syndrome among multiple sclerosis patients in Lebanon

BACKGROUND

Multiple sclerosis (MS) is often associated with fatigue, with an increased prevalence of sleep disorders compared to the general population, notably restless legs syndrome (RLS). The aim of this study was to evaluate the prevalence and severity of RLS as well the co-occurrence of spinal demyelination lesions in patients with MS in Lebanon.

METHODS

In this cross-sectional study, we consulted the MS database of the Lebanese association against Multiple Sclerosis and sent out questionnaires to 300 MS patients to screen then confirm the presence of RLS. The final sample included 28 MS participants with confirmed RLS. We conducted further questionnaires to collect demographic data, screen for comorbidities, gather spinal MRI results, and evaluate the severity of both diseases (using the EDSS and the JHRLSS).

RESULTS

Prevalence of RLS was 15% among MS patients in our study. 46.4% of RLS-affected MS patients had spinal cord demyelination lesions on their MRIs. Participants with MRI lesions had a lower severity score on the JHRLSS (p = 0.088). No association was found between the EDSS results and JHRLSS, demographic data, or comorbidities.

CONCLUSION

Restless legs syndrome is commonly found among patients with multiple sclerosis in Lebanon, is underdiagnosed, and ought to be systematically evaluated for in order to improve the patients' quality of life.

Iron Deficiency in Menstruating Adult Women: Much More than Anemia

Background: Iron deficiency anemia (IDA) is highly prevalent in women of child-bearing age. However, their nonhematological symptoms have been overlooked. This study aims to analyze the nonhematological features and symptoms of IDA in a group of women of reproductive age and the changes occurred during iron therapy. Materials and Methods: IDA women underwent dietary, physical activity, menstrual blood loss, and cognitive function assessment at baseline. Hematological and biochemical parameters were analyzed. Executive attention was tested by the flanker task and working memory by the 2-back task. Oral iron therapy (ferrous sulfate) was given to 35 women for 8 weeks and the changes in iron status, biochemical markers, cognitive function, and nonhematological symptoms were evaluated. Results: Patients presented nonhematological symptoms: pica, 32.4%; cheilitis, 20.6%; restless legs syndrome (RLS), 20.6%; diffuse hair loss, 55.9%; and ungual alterations, 38.2%. Two or more symptoms were present in 58.8% of women. Serum iron and working memory were correlated at baseline. Multivariate analyses show associations (odds ratio [OR], 95% confidence interval [CI]) between pica and reaction time in the working memory test (OR 2.14, 95% CI 1.19-3.87, p = 0.012); RLS with total serum protein (OR 0.08, 95% CI 0.06-0.92, p = 0.043); and cheilitis with mean corpuscular hemoglobin (OR 0.388, 95% CI 0.189-0.799, p = 0.01). Pica, cheilitis, and RLS completely resolved with iron therapy, and ungual alterations and hair loss improved in 92.3% and 84.2% of women, respectively. Better performance in executive attention and working memory was observed after iron therapy. Conclusions: More attention should be given to the nonhematological manifestations of IDA to improve the quality of life of menstruating women.

Efficacy of neuromuscular electric stimulation versus aerobic exercise on uraemic restless legs syndrome

Background

The prevalence of restless legs syndrome in haemodialysis patients is approximately ~30%, and it is significantly higher than in the general population. Restless legs syndrome is a sensory-motor disorder with negative effects on sleep and daytime activities that affect personal, family and occupational life. The overall impact of restless legs syndrome on quality of life is comparable to that of chronic and frustrating conditions such as depression and diabetes. The present study was conducted to compare the effect of neuromuscular electric stimulation with aerobic exercise on cases of uraemic restless legs syndrome.

Methods

A total of 60 chronic renal failure patients with uraemic restless legs syndrome aged 20 to 65 years participated in this study. Participants were allocated to receive neuromuscular electric stimulation or aerobic exercises. All participants were evaluated before the first session of treatment and after 3 months, at the end of the treatment. Normal and fast walk gait speed tests and the Five Times Sit-to-Stand Test and 60 second Sit-to-Stand Test were used to assess participants' physical status. The Restless Legs Syndrome Rating Scale was used to determine the level of restless legs syndrome severity.

Results

Neuromuscular electric stimulation resulted in significant improvements in all measures of physical performance and in Restless Legs Syndrome Rating Scale score when compared to baseline. Aerobic exercise produced significant improvements in all tests. At the end of the study, aerobic exercise had greater responses than neuromuscular electric stimulation in all parameters measured except the Five Times Sit-to-Stand Test.

Conclusions

Neuromuscular electrical stimulation may be used as an alternative to aerobic exercise to improve physical performance in cases of less severe restless legs syndrome in those unable or unwilling to participate in physical training.

Assessment of serum uric acid levels in patients with restless legs syndrome

In our study, the aim was to collect data in relation to our hypothesis that oxidative stress is effective in the etiopathogenesis of restless legs syndrome (RLS) by assessing the serum uric acid levels, an important biomarker of oxidative stress, among RLS patients. The study included a total of 281 patients with restless legs syndrome diagnosis according to the "2012 Revised International Restless Legs Syndrome Study Group Diagnostic Criteria". Disease severity was assessed according to the "International Restless Legs Syndrome Study Group Severity Scale". The control group comprised 237 healthy individuals with the same age and gender features as the control group. The result showed no statistically significant difference in the mean age and gender between RLS and control group (p = 0.923; p = 0.433). The hemoglobin, ferritin, and uric acid levels of patients with RLS were found to be low (p < 0.001). Total iron-binding capacity level was higher in patients (p < 0.01; p < 0.05). In RLS patients, the serum uric acid level was not affected by disease severity (p > 0.05). Variables affecting uric acid level in RLS patients were determined to be age, disease duration, and hemoglobin level. The hypothesis that uric acid level, accepted as a biomarker of oxidative stress, is important in the pathogenesis of restless legs syndrome is supported by our study.

Spinal Cord Stimulation in Patients With Chronic Pain and Restless Legs Syndrome: A Case Report

Restless legs syndrome can be a debilitating condition that affects a patient's ability to function and their quality of life. Neuromodulation may represent a potential option for nonpharmacological management of restless legs syndrome. We present 3 patients who have a chronic pain diagnosis and medically refractory restless legs syndrome that warranted neuromodulation. After neuromodulation, all 3 patients had improvement in their restless legs syndrome symptoms and were taking less pain medication, and 2 out of 3 had significantly improved functionality at short-term follow-up. This case series suggests that spinal cord stimulation may be a viable nonpharmacological treatment option for medically refractory restless legs syndrome.

Is Restless Legs Syndrome Associated with an Increased Risk of Mortality? A Meta-Analysis of Cohort Studies

Background

Restless legs syndrome (RLS) is a common sleep disorder,. although controversial, growing evidence relates the presence of RLS to an increased risk of mortality, mainly due to cardiovascular events. The aim of this article was to review the role of RLS as a risk factor of mortality according to independent cohort studies.

Methods

We performed a literature review via PubMed database for articles relating RLS and mortality. We used the random-effects model to calculate the pooled effect estimates on mortality. Heterogeneity between studies was assessed using quantitative and qualitative analysis.

Results

Out of 100 articles identified, 13 were finally included. Although studies were heterogeneous (p = 0.001), no significant publication bias was found. When all cohort studies were considered, the random-effects model yielded a significantly increased risk of mortality in RLS versus non-RLS patients (13 studies, hazard ratio [HR] = 1.52, 95% confidence interval [CI] 1.28-1.80). However, this association was not statistically significant when only cohort studies using the international RLS diagnostic criteria were considered (5 studies, HR = 1.63, 95% CI 0.94-2.81).

Discussion

The results of this meta-analysis suggest that RLS seems to be a risk factor of mortality, although this association is conditioned by the diagnostic criteria used in the studies. Future long-term follow-up standardized mortality studies are needed to address this important question that carries potential impact on population global health.

Restless legs syndrome and periodic limb movements during sleep in the Multi-Ethnic Study of Atherosclerosis

Study Objectives

To investigate the prevalence of concurrent periodic limb movements during sleep (PLMS) and restless leg syndrome (RLS), as well as the prevalence of PLMS and RLS separately. Additionally, we document these prevalences by age, race/ethnicity, sex, and obesity status.

Methods

Cross-sectional data from 2041 Multi-Ethnic Study of Atherosclerosis (MESA) Sleep ancillary study participants were used. PLMS (>15 periodic limb movements per hour of sleep) was measured by polysomnography. RLS symptoms were assessed using the 2009 International Restless Legs Syndrome Study Group clinical criteria.

Results

The prevalence of RLS with PLMS was 6.7%, RLS alone 16.1%, and PLMS alone 21.2%. RLS with PLMS was prevalent in 7.0% of whites, 4.9% of blacks, 10.1% of Hispanics, and 3.3% of Chinese-Americans. In adjusted models, odds of RLS with PLMS was higher for those older than 67 years versus those younger (odds ratio [OR] [95% confidence interval [CI]] = 1.62 [1.09-2.40]). Relative to white participants, the prevalence of RLS with PLMS tended to be lower among blacks (0.56 [0.32-0.96]). The prevalence of concurrent RLS and PLMS did not statistically differ by sex or obesity status. RLS alone was more common in women.

Conclusions

Approximately 7% of our sample had RLS with PLMS ("electro-clinical RLS"). This condition was more common among older individuals, did not vary by sex, and was less common among blacks. The findings provide some of the first information about the prevalence of concurrent RLS and PLMS in a community-based sample and show distinct sex and race associations for RLS versus electro-clinical RLS.

[Restless legs syndrome in ischemic stroke patients: clinical features and significance]

OBJECTIVE

To investigate the clinical features and implication of restless legs syndrome (RLS) in ischemic stroke patients.

METHODS

A total of 199 ischemic stroke patients were enrolled and assessed by polysomnography (PSG). RLS was identified according to criteria of International Restless Legs Syndrome Study Group. Epworth Sleepiness Scale (ESS), Mini-mental State Examination (MMSE) and Patient Health Questionnaire (PHQ-9) were used to evaluate the sleep quality, cognitive function and post-stroke depression, respectively. The National Institute of Health Stroke Scale (NIHSS) was used to evaluate the neurological function 3 months after stroke onset. Gender-and age-matched non-ischemic stroke patients with RLS (primary PLS) were selected as controls.

RESULTS

Twenty-two cases of RLS were identified among 199 ischemic stroke patients (11.1%). Generalized linear model and logistic regression showed that low serum ferritin level (β=-133.3 mg/L, 95%CI:-200.4--0.1, P<0.01), subcortical infarction (OR=4.05, 95%CI:1.15-14.18, P<0.05) and female (OR=2.54, 95%CI:1.04-6.23, P<0.05) were identified as the risk factors of RLS in ischemic stroke patients. Compared with ischemic stroke patients without RLS, ESS increased by 4.37 (95%CI:2.33-6.41, P<0.01), PHQ-9 increased by 2.17 (95%CI:0.39--3.94, P<0.05), and reduced NIHSS from the baseline deceased by 0.97 (95%CI:-1.79--0.15, P<0.05) in ischemic stroke patients with RLS. In addition, the incidence of moderate-severe depression increased (OR=4.27, 95%CI:1.40-13.10, P<0.05) in ischemic stroke patients with RLS. The index of periodic leg movements of sleep (PLMS) with arousal in ischemic stroke patients with RLS was significantly higher than that in patients with primary RLS (β=12.85, 95%CI:2.04-23.67, P<0.05).

CONCLUSIONS

RLS is common in ischemic stroke patients and has adverse influences on patients.

Serum C-reactive protein/albumin ratio and restless legs syndrome

OBJECTIVES

Our study aimed to assess the variation in serum C-reactive protein/albumin ratio (CAR), a biomarker of peripheral inflammation and oxidative stress, in patients with restless legs syndrome (RLS).

METHODS

The study included a total of 380 individuals including 197 with RLS diagnosis. RLS diagnosis was determined according to the "International Restless Legs Syndrome Study Group" questionnaire. Disease severity was assessed according to the "International Restless Legs Syndrome Study Group Severity Scale''.

RESULTS

The mean age of patients with restless legs syndrome was 52.5 ± 12.7 years, while the mean age in the control group was 50.8 ± 11.2, with no statistically significant difference found (p = 0.156). The hemoglobin, iron and ferritin levels in the patient group were lower than in the control group (p < 0.001; p < 0.01; p < 0.001), with total iron binding capacity levels higher than the control group (p < 0.001). The mean ferritin in the RLS group (49.8 ± 51.2) was lower than the control group (76.9 ± 44.7). In patients, the c-reactive protein, albumin and c-reactive protein/albumin ratio were found to be 0.21 ± 0.18, 4.43 ± 0.31 and 0.07 ± 0.05, respectively. When compared with the control group, the patient group had high c-reactive protein (CRP), CAR and low albumin levels (p < 0.001). Among patients with "very severe" disease severity, ferritin levels were found to be lower than those with "moderate" disease severity. Additionally, patients with "very severe" disease had albumin levels which were significantly low compared to those with "mild" disease severity (p < 0.05).

CONCLUSION

Our study supports the hypothesis that serum albumin level, ferritin, CRP, and CAR may be associated with restless legs syndrome.

Restless Legs Syndrome in Parkinson's Disease Patients: Clinical Features Including Motor and Nonmotor Symptoms

Background and Purpose

We investigated the frequency and clinical features of restless legs syndrome (RLS) in patients with Parkinson's disease (PD).

Methods

This study included 74 PD patients. RLS was diagnosed in face-to-face assessments of all of the subjects based on diagnostic criteria of the International Restless Legs Syndrome Study Group revised in 2003. We analyzed the clinical features of PD patients with and without RLS and compared the data to idiopathic RLS.

Results

The frequency of RLS in the cohort was 21.6% (n=16). Two (12.5%) of the patients with RLS were not treated with dopaminergic drugs, while 14 (24.1%) of the 58 patients without RLS received treatment with dopaminergic drugs. Anxiety, depression, and quality of life (QoL) were significantly worst in patients with RLS. PD patients with RLS had significantly worse sleep quality (p=0.003) and worse scores on the cardiovascular subscale of the Scales for Outcomes in Parkinson's Disease for Autonomic Symptoms (p=0.031) compared to those without RLS. In the group of PD patients with RLS, RLS preceding PD onset was related to a lower Hoehn and Yahr stage.

Conclusions

We found that the frequency of RLS in the present patients with PD was higher than that in our previous study of a general population of RLS subjects. Compared to the PD patients without RLS, the present PD patients with RLS suffered from worse sleep quality and QoL, depression, anxiety, and autonomic disturbances, especially those with cardiovascular problems.

Prevalence of restless legs syndrome in individuals with migraine: a systematic review and meta-analysis of observational studies

OBJECTIVE

Recent studies have shown an association between migraine and restless legs syndrome (RLS), but RLS prevalence among individuals with migraine differs substantially across studies. The present work aimed to comprehensively assess available evidence to estimate RLS prevalence among individuals with migraine and non-migraine controls.

METHOD

Web of Science, PubMed, Embase, Chinese National Knowledge Infrastructure, Wanfang, and SinoMed databases were searched for observational and case-control studies of RLS prevalence among individuals with migraine. Eligible studies were meta-analyzed using Stata 12.0 software.

RESULTS

Pooled RLS prevalence in migraine was 19%, and the prevalence was lower in Asia (16%) than outside Asia (21%). Pooled RLS prevalence was 18.8% among individuals with migraine with aura, and 18.5% among individuals with migraine without aura; the RLS prevalence in migraine with aura (MA) was higher than that of migraine without aura (MO) (OR 1.17, 95%CI 1.01-1.34; p = 0.037). Pooled RLS prevalence in a case-control study was significantly higher among individuals with migraine (17.9%) than among non-migraine controls (7.1%) (OR 2.65, 95%CI 2.26-3.10; p < 0.001).

CONCLUSION

Our meta-analysis provides the first reliable pooled estimate of RLS prevalence among individuals with migraine, and it provides strong evidence that RLS risk is higher among individuals with migraine than among controls.