Onset Of Restless Legs Syndrome Research Articles

Association among attention-deficit hyperactivity disorder, restless legs syndrome, and peripheral iron status: a two-sample Mendelian randomization study.

Epidemiological evidence indicates a high correlation and comorbidity between Attention Deficit Hyperactivity Disorder (ADHD) and Restless Legs Syndrome (RLS). We aimed to investigate the causal relationship and shared genetic architecture between ADHD and RLS, as well as explore potential causal associations between both disorders and peripheral iron status. We performed two-sample Mendelian randomization (MR) analyses using summary statistics from genome-wide meta-analyses of ADHD, RLS, and peripheral iron status (serum iron, ferritin, transferrin saturation, and total iron binding capacity). Additionally, we employed linkage disequilibrium score regression (LDSC) to assess genetic correlations between ADHD and RLS using genetic data. Our MR results supports a causal effect from ADHD (as exposure) to RLS (as outcome) (inverse variance weighted OR = 1.20, 95% CI: 1.08-1.34, p = 0.001). Conversely, we found no a causal association from RLS to ADHD (inverse variance weighted OR = 1.04, 95% CI: 0.99-1.09, p = 0.11). LDSC analysis did not detect a significant genetic correlation between RLS and ADHD (Rg = 0.3, SE = 0.16, p = 0.068). Furthermore, no evidence supported a causal relationship between peripheral iron deficiency and the RLS or ADHD onset. However, RLS may have been associated with a genetic predisposition to reduced serum ferritin levels (OR = 1.20, 95% CI: 1.00-1.04, p = 0.047). This study suggests that ADHD is an independent risk factor for RLS, while RLS may confer a genetic predisposition to reduced serum ferritin levels. The GWAS summary data utilized originated from populations of European ancestry, limiting the generalizability of conclusions to other populations. The potential co-occurrence of RLS in individuals with ADHD should be considered during diagnosis and treatment. Moreover, iron supplementation may be beneficial for alleviating RLS symptoms.

The long-term effect of work schedule, shift work disorder, insomnia and restless legs syndrome on headache among nurses: A prospective longitudinal cohort study.

The preset study aimed to explore whether work schedules and sleep disorders predict the onset of headache. A longitudinal study was conducted with questionnaire data from 2014 (baseline) and 2017 (follow-up) on work schedule, number of night shifts, number of quick returns, insomnia, shift work disorder (SWD), restless legs syndrome (RLS) and validated headache diagnoses among 1560 Norwegian nurses. Associations were explored by multivariate regression analyses. Work related factors at baseline did not predict onset of headache three years later. In the adjusted logistic regressions, insomnia at baseline predicted increased risk of new onset of migraine (odds ratio (OR) = 1.58; 95% confidence interval (CI) = 1.08-2.33), chronic headache (OR = 2.02; 95% CI = 1.04-4.66) and medication-overuse headache (OR = 3.79; 95% CI = 1.26-11.42) at follow-up. SWD at baseline predicted new onset of migraine (OR = 1.64; 95% CI = 1.07-2.50) and RLS at baseline predicted new onset of headache ≥1 day per month (OR = 1.55; 95% CI = 1.01-2.36) and migraine (OR = 1.55; 95% CI = 1.03-2.32) at follow-up. No factors predicted tension-type headache. Overall, work related factors did not predict the onset of headache three years later, whereas insomnia, SWD and RLS at baseline all increased the risk of future headaches.

LAG3/CD4 Genes Variants and the Risk for Restless Legs Syndrome.

According to several studies, inflammatory factors could be related to the pathogenesis of idiopathic restless legs syndrome (RLS). In addition, RLS and Parkinson's disease (PD) have shown a possible relationship, and recent studies have shown an association between CD4 rs1922452 and CD4 rs951818 single nucleotide variants (SNVs) and the risk for PD. For these reasons, we investigated the possible association between common variants in the LAG3/CD4 genes (which encoded proteins involved in inflammatory and autoimmune responses) and the risk for RLS in a Caucasian Spanish population. We assessed the frequencies of CD4 rs1922452, CD4 rs951818, and LAG3 rs870849 genotypes and allelic variants in 285 patients with idiopathic RLS and 350 healthy controls using a specific TaqMan-based qPCR assay. We also analyzed the possible influence of the genotypes' frequencies on several variables, including age at onset of RLS, gender, family history of RLS, and response to drugs commonly used in the treatment of RLS. We found a lack of association between the frequencies of genotypes and allelic variants of the 3 SNVs studied and the risk of RLS, and a weak though significant association between the CD4 rs1922452 GG genotype and an older age at onset of RLS. With the exception of this association, our findings suggest that common SNVs in the CD4/LAG3 genes are not associated with the risk of developing idiopathic RLS in Caucasian Spanish people.

Peripheral Iron Metabolism is Associated with Leg Movements on Polysomnography but Not with the Severity of Restless Legs Syndrome or Its Impact on Patients.

PurposeThis study investigated the associations of peripheral iron status with different manifestations of restless legs syndrome (RLS), including leg movements (LMs) on polysomnography (PSG), disease severity, and impact on patients.Patients and MethodsIn this cross-sectional study, 108 patients with RLS were enrolled at Sir Run Run Shaw Hospital’s Center for Sleep Medicine. Demographic information, disease characteristics, RLS severity, and impact on patients were assessed through a semi-structured questionnaire. Peripheral iron indicators [serum ferritin, iron, and transferrin concentrations; unsaturated iron-binding capacity (UIBC) and total iron-binding capacity (TIBC); transferrin saturation (TSAT)] were measured following PSG to assess sleep stages, respiratory events, microarousals and LM parameters. Data from patients with and without ferritin concentration < 50 µg/L were compared in crude analyses, and Spearman correlations of other iron indicators with RLS data were examined. An ordinal logistic regression model was used to adjust for age, sex, body mass index, years of education, age at the time of RLS onset, prior treatment (yes/no), C-reactive protein (CRP)/hemoglobin level, total sleep time and apnea-hypopnea index.ResultsMultivariate analysis showed that periodic LMs during sleep (PLMS) and other LM parameters were significantly associated with a ferritin concentration < 50 µg/L, UIBC, TIBC, and serum transferrin concentration, but not serum iron or TSAT. By contrast, the severity and impact of RLS were not associated with a ferritin concentration < 50 µg/L or other peripheral iron indicators in the multivariate model.ConclusionIn this study, peripheral iron status was associated mainly with motor components (LMs on PSG) rather than sensory components (severity and impact of RLS) after adequately controlling for potential confounders, such as CRP and hemoglobin levels. Commonly used peripheral iron metabolism indicators may therefore not be ideal biomarkers of RLS severity or impact on patients.

Restless Legs Syndrome in X-linked adrenoleukodystrophy

Objective/backgroundX-linked adrenoleukodystrophy (ALD) is a neurodegenerative disease that causes progressive gait and balance problems. Leg discomfort, sleep disturbances, and pain contribute to daily disability. We sought to investigate the prevalence and severity of Restless Legs Syndrome (RLS) in patients with ALD. Patients/methodsWe administered questionnaires and conducted diagnostic telephone interviews to assess RLS severity. We retrospectively extracted data from neurological examinations, functional gait measures, and laboratory assessments. Results and conclusionsThirty-two adults with ALD (21 female, 11 male) were recruited to participate. Thirteen patients (40.6%) had RLS (10/21 females and 3/11 males). The median age of RLS onset was 35 years [IQR = 22–54]. Patients with RLS had more signs and symptoms related to myelopathy, but not the brain demyelination seen in ALD. This pilot study suggests a high prevalence of RLS in adults with ALD, which may contribute to sleep problems and impair quality of life.

Restless legs syndrome in systemic lupus erythematosus: A case-control study.

Sleep disturbances in systemic lupus erythematosus (SLE) are not well understood. The restless legs syndrome (RLS) is one of the frequent occurring sleep disturbances in SLE. The aim of this study was to evaluate the prevalence of RLS and its characteristics in SLE. We evaluated, in a prospective case-control study, 26 patients with SLE and 26 patients without SLE in an age- and sex-matched control group. An RLS-positive diagnosis met International RLS Study Group (IRLSSG) criteria. We used standardized questionnaires, which included demographic data, medical history and sleep assessment. We used validated questionnaires and scales to assess sleep. There were 23/26 females (88.46%) in each group; the mean patient age in the SLE subgroup was 51.65 years, while in the control subgroup, 52.07 years (range 30-74). Nine (34.2%) patients had RLS-positive criteria in the SLE group and 2 (7.69%) of 26 in the control group. Eight out of 9 patients described RLS onset after SLE was diagnosed. In the SLE group, 8 cases were of moderate severity and 1 was considered mild. The control group had one mild and one moderate case of RLS. RLS prevalence in SLE is higher and the quality of sleep is poorer compared with the control group.

New onset of restless legs syndrome in pregnancy in a prospective multiracial cohort: Incidence and risk factors.

To determine whether the incidence and risk factors of restless legs syndrome (RLS) in pregnancy differ by race/ethnicity, we estimated relative risks of demographic, socioeconomic, and nutritional factors in association with risk of any incident RLS in pregnancy in a cohort of 2,704 healthy pregnant women without prior RLS. Using data from the multicenter, multiracial National Institute of Child Health and Human Development (NICHD) Fetal Growth Studies-Singletons, we examined the incidence of RLS from early pregnancy to near delivery through up to 6 assessments. Multivariable Poisson models with robust variance were applied to estimate relative risks (RRs). The cumulative incidence of RLS in pregnancy was 18.1% for all women, 20.3% for White women, 15.4% for Black women, 17.1% for Hispanic women, and 21.1% for Asian women. Among Hispanic women, older age (RR [reference ≤25 years]: 25-35 years, 1.51; 95% confidence interval [CI] 1.05-2.16; ≥35 years, 1.58; 95% CI 0.93-2.68), anemia (RR [reference no]: yes, 2.47; 95% CI 1.31-4.64), and greater total skinfolds of the subscapular and triceps sites, independent of body mass index (RR [reference quartile 1]: quartile 5, 2.54; 95% CI 1.30-4.97; p trend = 0.01) were associated with higher risk of RLS, while multiparity was associated with a lower risk (RR [reference nulliparity]: 0.69; 95% CI 0.50-0.96). In Black women, greater skinfolds and waist circumference were associated with higher risk of pregnancy RLS, although the trends were less clear. The incidence of RLS in pregnancy was high and differed by race/ethnicity, which is likely accounted for by differences in other risk factors, such as age, parity, and nutritional factors.

Hepcidin and ferritin levels in restless legs syndrome: a case\u2013control study

The association between restless legs syndrome (RLS) and iron homeostasis remains unclear. We compared serum hepcidin and ferritin levels in patients with RLS and controls, and assessed their relationships with RLS phenotype, drug intake, and history of augmentation syndrome. 102 drug-free RLS patients (age 58.9 [24.5–77.2], 63 females) and 73 controls (age 56.8 [23.46–76.6], 45 females) underwent a polysomnography recording. Hepcidin levels were quantified by ELISA. 34 RLS patients had a second assessment after starting dopaminergic drugs. Ferritin level was low (< 50 µg/l) in 14.7% of patients and 25% of controls, with no between-group differences in the mean values. Hepcidin levels were higher in patients even after adjustment for confounding factors, and excluding participants with low ferritin levels. Ferritin and hepcidin levels were comparable before and after treatment, and between patients with (n = 17) and without history of augmentation. Ferritin and hepcidin levels correlated with age, body mass index, and periodic leg movements. Higher hepcidin levels were associated with older age, older age at RLS onset, less daytime sleepiness and familial RLS. In conclusion, serum hepcidin levels but not ferritin were higher in RLS patients regardless of treatment and history of augmentation. Serum hepcidin may be a more relevant biomarker of RLS than ferritin.

0798 “Uncovering My Feet Alleviates My Restless Legs”: Impact of Different Activities and Conditions on Restless Legs Symptoms

Abstract Introduction The restless legs syndrome (RLS) is a resting wake state disorder with inactivity/decreased movement as an aggravating factor and activity/increased movement as an alleviating factor. Other activities and conditions may impact RLS symptoms but have not been systematically studied. Methods Fifty-six patients with primary severe RLS (age: 64.1±11.3; 66% women) responded about the effect of 20 activities/conditions on their RLS symptoms. Responses were assigned a numerical value: Aggravation (-1), No effect/Don’t know (0), Alleviation (+1), with calculating a mean effect score for each activity/condition and using a sign test to determine if that score was significantly above or below zero (no effect). Responses were further analyzed based on age, age at RLS onset, duration of RLS, RLS severity, gender, Familial/Non-familial RLS, and Painful/Non-Painful RLS. Association of continuous variables and categorical variables with each activity/condition was examined using Spearman correlation test and Fisher exact test, respectively. Bonferroni p threshold was set at p=0.00036. Results Activities/conditions with significant (p&amp;lt;0.0001) positive mean effect scores were: Feet uncovering (0.70); Leg massaging (0.63); Cold showers (0.54); and Manual activities (0.46). Activities with significant negative mean effect scores were: Vehicle passenger (-0.80); Show attendance (-0.70); Bedsheets weight on legs (-0.57); Watching TV (-0.54); High ambient temperature (-0.45); During meals (-0.39) (all p&amp;lt;0.0001); and Bedsheets rubbing on legs (-0.34; p=0.0002). Activities/conditions with no significant (all p&amp;gt;0.00036) mean effect scores were: Driving (0.00); Gambling (0.02); Professional activities (0.13); Hot showers (0.13); Using computer (0.14); Low ambient temperature (0.21); Sexual activities (0.27); Mental activities (0.29); and Sports activities (0.34). There was no significant association between each activity/condition and age, age at RLS onset, duration of RLS, RLS severity, gender, Familial/Non-familial RLS, or Painful/Non-Painful RLS. Conclusion There is a wide range of impact of different activities/conditions on RLS symptoms. These could be further considered in the non-pharmacological treatment or prevention of RLS symptoms. Support This study was not funded.

Correlates of Nonanemic Iron Deficiency in Restless Legs Syndrome.

Objective: Iron deficiency anemia (IDA) is a well-known cause of secondary restless legs syndrome (RLS). Iron deficiency without anemia (IDNA) is insidious, and its association with RLS is less evaluated. We investigate prevalence and features of IDNA in a consecutive cohort of patients with RLS.Methods: We included sequential primary RLS patients and RLS patients with IDA. We also recruited age- and gender-matched healthy controls. RLS mimics and other comorbidities were carefully excluded.Results: One-hundred and ninety-six RLS patients without anemia, 26 RLS patients with IDA, and 63 controls were included. 42.3% of RLS patients without anemia had iron deficiency. Women were much more susceptible for IDNA with a relative risk of 5.51 (p < 0.0001). Women with IDNA and RLS had younger age both at interview and at RLS onset compared to women with RLS without iron deficiency (NID) (P < 0.01). IDNA RLS patients showed a tendency to higher risk of severe/very severe tiredness or sleepiness during the day as compared to NID RLS patients. Furthermore, IDNA RLS patients had longer duration of RLS (P < 0.01 in men, P < 0.05 in women) and younger age at onset (only in men, P < 0.05) compared to IDA RLS patients.Conclusion: IDNA is frequent in RLS and iron deficiency may be severe despite a normal hemoglobin level. Women are at much higher risk for IDNA, and IDNA in women presents some specific clinical features. Features of IDNA RLS are different from IDA RLS. Regular screening of peripheral iron parameters even in patients with normal blood counts is recommended for timely optimal management.

‘Is RLS a harbinger and consequence of MS?: Striking results of the ‘RELOMS-T’ study’

BackgroundAlthough studies report a high prevalence rate of restless legs syndrome (RLS) among patients with multiple sclerosis (PwMS) ranging from 13.3 to 65.1%, little is known about the causes of this relationship. MethodsTo ascertain the prevalence, features and impact of RLS among PwMS a nation-wide, multicenter, prospective and a cross-sectional survey, designed to reflect all of the PwMS throughout Turkey, was conducted in 13 centers. Exploring the relationship of the two conditions could possibly contribute to the understanding of the causes of the high and wide-ranging prevalence rates and the pathophysiology of both diseases. ResultsOf the 1068 participants 173 (16,2%) found to have RLS [RLS(+)] and 895 (83,8%) did not [RLS(-)]. Among the RLS(+) 173, all but 8 patients (4,6%) were underdiagnosed in terms of RLS. More than half of the patients with RLS had ‘severe’ or ‘very severe’ RLS. The onset of RLS was before or synchronous with the onset of MS in about a half of our patients. ConclusionWe conclude that RLS should be meticulously investigated in PwMS and MS can be a direct cause of RLS at least in part of PwMS. Our data about the timing of the onset of MS and RLS, along with the high prevalence of RLS in PwMS suggest that the pathologic changes in the initial phases of MS can possibly trigger RLS symptoms.

Fótaóeirð - yfirlitsgrein

Restless legs syndrome (RLS) is a common disorder with a prevalence between 10-20% in Iceland. There are two forms of RLS, idiopathic and secondary. Symptom onset of RLS before the age of 45 suggests an idiopathic form with no known underlying cause but inheritance. Symptom onset after age of 45 indicates a secondary form with an underlying cause without inheritance. Causes for secondary forms are for example: iron depletion, uraemia and polyneuropathy. Symptoms of RLS are uncomfortable and unpleasant deep sensations in the legs that are felt at rest, accompanied by an urge to move the legs, typically just before sleep. Accompanying RLS is a sleep disturbance that can lead to daytime somnolence, decreased quality of life, poor concentration, memory problems, depression and decreased energy. Dopamine agonists are currently the first line treatment for RLS. restless legs, periodic limb movements, sleep disturbance, dopamine agonists.

Blood pressure profile and endothelial function in restless legs syndrome

Restless legs syndrome (RLS) is frequently comorbid with hypertension and cardiovascular diseases; however this relationship and underlying mechanisms remain controversial. After clinical evaluation, 84 drug-free patients with primary RLS (53 women; mean age 55.1 ± 12.3 years) and 76 controls (47 women; mean age 52.2 ± 15.3 years) underwent 24-hour ambulatory blood pressure (BP) and polysomnographic monitoring, and peripheral arterial tonometry to assess endothelial function for 61 patients and 69 controls. Hypertension was diagnosed in 11.9% of patients with RLS based on office measurement, and in 46.4% on the 24 h recording, with nighttime hypertension, two times more frequent than daytime hypertension. Periodic limb movement during sleep (PLMS), markers of sleep fragmentation, and systolic and mean BP non-dipping profile were more frequent among patients. BP non-dipping status was associated with older age, later RLS onset and diagnosis, RLS severity and higher sleep fragmentation. The mean 24-hour, daytime and nighttime BP values, the frequency of hypertension and the endothelial function were comparable between groups. However, both systolic and diastolic BP trajectories over a 24-hour period differed between groups. In conclusion, patients with RLS exhibit a 24-hour BP deregulation with increased frequency of systolic non-dipping profiles that could worsen the risk for CVD morbidity and mortality.

Clinical features and subtypes of restless legs syndrome in Chinese population: a study of 359 patients

BackgroundThe clinical spectrum of restless legs syndrome (RLS) has not been described in a Chinese population. We aim to evaluate the detailed clinical profile in a cohort of unselected RLS patients in China. MethodsWe enrolled RLS patients continuously according to the diagnostic criteria. Laboratory examinations were performed to exclude mimics and notable comorbidities. ResultsA total of 359 patients with RLS were enrolled. RLS symptoms were mostly symmetrical (65.2%), and purely unilateral RLS was not common (5.6%); however, unilateral dominant RLS was relatively more common. Only 1.1% of RLS patients reported no unpleasant sensations in the legs. The largest proportion of RLS patients described their uncomfortable sensation as indescribable (43.5%) and reported soreness (40.4%). In all, 8.9% of RLS patients described their abnormal sensation as painful, and 34.5% of RLS patients reported their symptoms fluctuated with seasonal trends. This population had a higher likelihood of an RLS family history. RLS patients with summer exacerbation had a younger age at RLS onset and longer disease duration (p < 0.01). Iron deficiency without anemia was common in Chinese RLS patients. Early-onset RLS patients were more likely to have a positive family history (p < 0.01), more summer worsening of symptoms (p < 0.01) and more severely disturbed peripheral iron status (p < 0.01) when compared to late-onset RLS patients. ConclusionThe subjective description is somewhat different, with Chinese RLS patients reporting less pain and more soreness than patients from Western countries. Seasonal fluctuation and iron deficiency without anemia are frequently seen in Chinese RLS patients and predict some other features. Differentiating these various subtypes can facilitate optimal management.

Gamma-aminobutyric acid (GABA) receptors genes polymorphisms and risk for restless legs syndrome.

The possible role of gammaaminobutyric acid (GABA) in the pathophysiology of restless legs syndrome (RLS) is suggested by the symptomatic improvement achieved with GABAergic drugs. Thalamic GABA levels have shown positive correlation with periodic limb movements indices and with RLS severity. We tried to investigate the possible association between the most common single nucleotide polymorphisms (SNPs) in the GABA receptors (GABR) genes rho1, 2, and 3 (GABRR1, GABRR2, GABRR3), alpha4 (GABRA4), epsilon (GABRE), and theta (GABRQ) with the risk of developing RLS. We studied the genotype and allelic variant frequencies of the most common SNPs in the GABRR1(rs12200969, rs1186902), GABRR2(rs282129), GABRR3(rs832032), GABRA4(rs2229940), GABRE(rs1139916), and GABRQ(rs3810651) genes in 205 RLS patients and 230 age- and gender-matched healthy controls using specific TaqMan assays. The frequencies of the GABRR3 rs832032TT genotype and the allelic variant GABRR3 rs832032T were significantly higher in RLS patients than in controls (odds ratio [95% confidence intervals] 7.08[1.48-46.44] and 1.66[1.16-2.37], respectively), although only the higher frequency of the rs832032T allele remained as significant after multiple comparison analysis, both in the whole series and in the female gender. The frequencies of the other genotypes of allelic variants did not differ significantly between RLS patients and controls. RLS patients carrying the GABRA4 rs2229940TT genotype showed a significantly younger age at onset of RLS symptoms than those with the other two genotypes. These results suggest association between GABRR3rs832032 polymorphism and the risk for RLS, and a modifier effect of GABRA4 rs2229940 on the age of onset of RLS.

Association between serum hepcidin level and restless legs syndrome.

To better understand the role of iron homeostasis dysregulation in restless legs syndrome, we compared serum hepcidin and ferritin levels in drug-free patients with primary restless legs syndrome and healthy controls and studied the relationship between hepcidin level and restless legs syndrome severity. One hundred and eight drug-free patients with primary restless legs syndrome (65 women; median age, 61.5 years) and 45 controls (28 women; median age, 53.9 years) were enrolled. Inclusion criteria were: normal ferritin level (>50 ng/mL) and absence of iron disorders, chronic renal or liver failure, and inflammatory or neurological diseases. Each subject underwent a thorough clinical examination and a polysomnography assessment. Serum hepcidin-25 was quantified using a validated mass spectrometry method. Restless legs syndrome severity was evaluated according to the International Restless Legs Syndrome Study Group. Despite no group difference between normal ferritin levels and demographic features, serum hepcidin level and hepcidin/ferritin ratio were higher in patients than in controls. Hepcidin level and hepcidin/ferritin ratio, but not ferritin level, were positively correlated with periodic leg movements during sleep and wakefulness in the whole sample. Hepcidin level seem to be associated with restless legs syndrome severity in a complex U-shaped relationship, without relationship with age at restless legs syndrome onset, positive family history, sleep and depressive symptoms, genetic background, and polysomnographic measurements. No relationship was found between ferritin level and restless legs syndrome severity. In drug-free patients with primary restless legs syndrome, hepcidin level is higher than in controls and may be associated with restless legs syndrome clinical severity. This result emphasizes the complex peripheral iron metabolism deregulation in restless legs syndrome, opening potential perspectives for a personalized approach with a hepcidin antagonist. © 2018 International Parkinson and Movement Disorder Society.

Restless legs syndrome is highly prevalent in patients with post-polio syndrome

ObjectiveFew studies have quantified the prevalence of restless legs syndrome (RLS) in patients with post-polio syndrome (PPS). Our objective was to assess the prevalence and severity of RLS in patients with PPS and to examine the demographic characteristics of this population. MethodThis was a cross-sectional study conducted from April 2010 to May 2012 at the outpatient Neuromuscular Disorders clinic of Universidade Federal de São Paulo, São Paulo, Brazil. We evaluated 119 patients with PPS, consecutively recruited, and investigated for RLS based on the diagnostic criteria established by the International Restless Legs Syndrome Study Group (IRLSSG). Patients were evaluated with the Brazilian version of the IRLSSG severity scale. ResultsThe prevalence of RLS was 36% (n = 43; 32 women and 11 men). The ages at onset of RLS (median = 41 years) and PPS (median = 41 years) were concurrent, and the correlation between onset of symptoms of RLS and onset of symptoms of PPS was positive and very strong (Spearman r = 0.93, p = 0.01). The median RLS severity was 23 (range, 20–28). Low educational achievement and depression were predictive of RLS development. ConclusionIn the largest population of patients with PPS studied to date, our results indicate a high prevalence of RLS, marked disease severity, and concomitant onset of both conditions in many patients with PPS. Further studies are needed to elucidate a possible pathophysiologic mechanism linking these two conditions. We suggest that all post-polio patients with sensory and motor complaints in the legs be investigated for RLS.

Restless legs syndrome and cardiovascular diseases: A case-control study.

ObjectiveThe association between restless legs syndrome (RLS), cardiovascular diseases (CVD) and hypertension is inconsistent. This case-control study examined i) the association between primary RLS, CVD and hypertension by taking into account many potential confounders and ii) the influence of RLS duration, severity and treatment, sleep and depressive symptoms on CVD and hypertension in primary RLS.MethodsA standardized questionnaire to assess the RLS phenotype, history of CVD and hypertension, sleep and depressive symptoms, drug intake and demographic/clinical features was sent to the France-Ekbom Patients Association members. A CVD event was defined as a self-reported history of coronary heart disease, heart failure, arrhythmia or stroke. Hypertension was also self-assessed. Current treatment for hypertension and arrhythmia also defined underlying hypertension and arrhythmia. Controls without RLS and without consanguinity were chosen by the patients.Results487 patients with primary RLS (median age 71 years; 67.4% women) and 354 controls (68 years, 47.7% women) were included. Most of the patients (91.7%) were treated for RLS, especially with dopaminergic agonists. The median age of RLS onset was 45 years. CVD and hypertension were associated with RLS in unadjusted association, but not after adjustment for age, sex and body mass index. Patients with RLS and with CVD and/or hypertension were significantly older, with hypercholesterolemia, sleep apnea and older age at RLS and at daily RLS onset compared with patients without CVD and/or hypertension. No significant difference was found for other RLS features, ferritin levels, daytime sleepiness, insomnia and depressive symptoms.ConclusionDespite some limitations in the design of this study, we found that most of the treated patients for primary RLS had no association with CVD and hypertension after controlling for key potential confounders. Comorbid CVD or hypertension was associated with cardiovascular risk factors, but not with RLS features except for older age at onset.

Objective Sleep Quality in Subjects with Restless Legs Syndrome versus with Psychophysiological Insomnia: Polysomnography and Cardiopulmonary Coupling Analysis

Objectives: To compare the sleep quality in the view of polysomnography (PSG) and cardiopulmonary coupling (CPC) analysis in subjects with restless legs syndrome (RLS) versus with psychophysiological insomnia (PPI). Methods The PSG data of 109 subjects with RLS and 86 with PPI (apnea-hypopnea index <5/h) were collected. All subjects reported sleep onset and maintenance insomnia. CPC parameters were obtained using CPC analyzer in RemLogic. Sleep spectrogram by CPC analyses categorized sleep as “stable” [high-frequency coupling (HFC), 0.1–0.4 Hz] and “unstable” [low-frequency coupling (LFC), 0.1–0.01 Hz], independent of sleep stages. We compared PSG and CPC parameters between two groups and performed correlation analyses to find the PSG parameters to affect CPC parameters. Results In PSG parameters, subjects with PPI showed significantly longer sleep latency (14.2±20.06 vs. 27.5±34.96, p<0.001), and decreased sleep efficiency (SE, 80.5±14.96 vs. 76.5±14.45, p=0.009) than RLS. CPC parameters were not significantly different between groups. In both groups HFC was positively correlated with total sleep time and SE and was negatively associated with time of wake after sleep onset in both groups. Meanwhile, very LFC showed the opposite results to HFC with the same PSG parameters. Conclusions Although subjects with RLS or PPI present sleep onset and maintenance insomnia, objective sleep quality was worse in PPI than RLS. It suggests that CPC as a factor to differentiate sleep quality between the RLS and the PPI has a limited role. Keywords: Sleep quality, Polysomnography, Restless legs syndrome, Psychophysiological insomnia, Cardiopulmonary coupling

Parkinson's Disease and Restless Legs Syndrome

Aims: Various sleep-related complications are common in Parkinson's disease (PD). The prevalence of restless legs syndrome (RLS) and its association with other symptoms were studied. Methods: Altogether, 1,447 Parkinson patients, aged 43-89, participated in a questionnaire study. Results: The response rate was 59.0% and of these, 68% returned fully answered questionnaires (n = 577). RLS occurred in 20.3% of the PD subjects. In patients with RLS, the symptoms occurred in 81.9% at least once weekly. The degree of severity was moderate in 42.7%, severe in 23.9% and very severe in 15.4%. Daytime sleepiness, fatigue, chronic insomnia, sleep maintenance insomnia, intense dreaming, and low quality of life were more common in patients with RLS than in patients without RLS. The occurrence of early onset RLS (onset ≤ age of 45 years) was 4.2%. The occurrences of late onset (>45 years) drug naïve RLS and late onset RLS (with dopaminergic medication) were 5.4 and 10.4%, respectively. Conclusion: In patients with PD, the early onset of RLS resembles idiopathic RLS with typical gender distribution and familial trait. Late onset of RLS is more common than idiopathic RLS.