Review of the role of the endogenous opioid and melanocortin systems in the restless legs syndrome.

Restless legs syndrome (RLS) is responsive to opioid, dopaminergic and iron-based treatments. Receptor blocker studies in RLS patients suggest that the therapeutic efficacy of opioids is specific to the opioid receptor and mediated indirectly through the dopaminergic system. An RLS autopsy study reveals decreases in endogenous opioids, ß-endorphin and perhaps Met-enkephalin in the thalamus of RLS patients. A total opioid receptor knock-out (mu, delta and kappa) and a mu-opioid receptor knock-out mouse model of RLS show circadian motor changes akin to RLS and, although both models show sensory changes, the mu-opioid receptor knock mouse shows circadian sensory changes closest to those seen in idiopathic RLS. Both models show changes in striatal dopamine, anaemia and low serum iron. However, only in the total receptor knock-out mouse do we see the decreases in serum ferritin that are normally found in RLS. There are also decreases in serum iron when wild-type mice are administered a mu-opioid receptor blocker. In addition, the mu-opioid receptor knock-out mouse also shows increases in striatal zinc paralleling similar changes in RLS. Adrenocorticotropic hormone and α-melanocyte stimulating hormone are derived from pro-opiomelanocortin as is ß-endorphin. However, they cause RLS-like symptoms and periodic limb movements when injected intraventricularly into rats. These results collectively suggest that an endogenous opioid deficiency is pathogenetic to RLS and that an altered melanocortin system may be causal to RLS as well.

Epigenetic Association Analyses and Risk Prediction of RLS.

BACKGROUND: As opposed to other neurobehavioral disorders, epigenetic analyses and biomarkers are largely missing in the case of idiopathic restless legs syndrome (RLS). OBJECTIVES: Our aims were to develop a biomarker for RLS based on DNA methylation in blood and to examine DNA methylation in brain tissues for dissecting RLS pathophysiology. METHODS: Methylation of blood DNA from three independent cohorts (n = 2283) and post-mortem brain DNA from two cohorts (n = 61) was assessed by Infinium EPIC 850 K BeadChip. Epigenome-wide association study (EWAS) results of individual cohorts were combined by random-effect meta-analysis. A three-stage selection procedure (discovery, n = 884; testing, n = 520; validation, n = 879) established an epigenetic risk score including 30 CpG sites. Epigenetic age was assessed by Horvath's multi-tissue clock and Shireby's cortical clock. RESULTS: EWAS meta-analysis revealed 149 CpG sites linked to 136 genes (P < 0.05 after Bonferroni correction) in blood and 23 CpG linked to 18 genes in brain (false discovery rate [FDR] < 5%). Gene-set analyses of blood EWAS results suggested enrichments in brain tissue types and in subunits of the kainate-selective glutamate receptor complex. Individual candidate genes of the brain EWAS could be assigned to neurodevelopmental or metabolic traits. The blood epigenetic risk score achieved an area under the curve (AUC) of 0.70 (0.67-0.73) in the validation set, comparable to analogous scores in other neurobehavioral disorders. A significant difference in biological age in blood or brain of RLS patients was not detectable. CONCLUSIONS: DNA methylation supports the notion of altered neurodevelopment in RLS. Epigenetic risk scores are reliably associated with RLS but require even higher accuracy to be useful as biomarkers. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

A Randomized, Placebo-Controlled Crossover Study with Dipyridamole for Restless Legs Syndrome.

BACKGROUND: New pharmacological targets are needed for restless legs syndrome. Preclinical data suggest that a hypoadenosinergic state plays an important pathogenetic role. OBJECTIVE: The objective of this study was to determine whether inhibitors of equilibrative nucleoside transporters, for example, dipyridamole, could provide effective symptomatic treatment. METHODS: A 2-week double-blind, placebo-controlled crossover study assessed the efficacy of dipyridamole (possible up-titration to 300 mg) in untreated patients with idiopathic restless legs syndrome. Multiple suggested immobilization tests and polysomnography were performed after each treatment phase. Severity was assessed weekly using the International Restless Legs Rating Scale, Clinical Global Impression, and the Medical Outcomes Study Sleep scale. The primary end point was therapeutic response. RESULTS: Twenty-eight of 29 patients recruited were included. International Restless Legs Rating Scale scores improved from a mean ± standard deviation of 24.1 ± 3.1 at baseline to 11.1 ± 2.3 at the end of week 2, versus 23.7 ± 3.4 to 18.7 ± 3.2 under placebo (P < 0.001). Clinical Global Impression, Medical Outcomes Study Sleep, and Multiple Suggested Immobilization Test scores all improved (P < 0.001). The mean effective dose of dipyridamole was 217.8 ± 33.1 mg/d. Sleep variables improved. The mean periodic leg movement index at the end of treatment with dipyridamole was 8.2 ± 3.5 versus. 28.1 ± 6.7 under placebo. Side effects (dipyridamole vs placebo) included abdominal distension (18% vs. 7%), dizziness (10.7% vs 7.1%), diarrhea, and asthenia (each 7.1% vs 3.6%). CONCLUSIONS: Dipyridamole has significant therapeutic effects on both sensory and motor symptoms of restless legs syndrome and on sleep. Our findings confirm the efficacy of dipyridamole in restless legs syndrome predicted from preclinical studies and support a key role of adenosine in restless legs syndrome. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Treatment of restless legs syndrome: Evidence-based review and implications for clinical practice (Revised 2017)§.

The objective of the current review was to update the previous evidence-based medicine review of treatments for restless legs syndrome published in 2008. All randomized, controlled trials (level I) with a high quality score published between January 2007 and January 2017 were reviewed. Forty new studies qualified for efficacy review. Pregabalin, gabapentin enacarbil, and oxycodone/naloxone, which did not appear in the previous review, have accrued data to be considered efficacious. Likewise, new data enable the modification of the level of efficacy for rotigotine from likely efficacious to efficacious. Intravenous ferric carboxymaltose and pneumatic compression devices are considered likely efficacious in idiopathic restless legs syndrome. Bupropion and clonidine were reviewed, but the lack of data determined a rating of insufficient evidence for efficacy. The following interventions continue to be considered efficacious as in 2008: levodopa, ropinirole, pramipexole, cabergoline, pergolide, and gabapentin. Bromocriptine, oxycodone, carbamazepine, and valproic acid are considered likely efficacious. Oral iron is nonefficacious in iron-sufficient subjects, but its benefit for patients with low peripheral iron status has not been adequately evaluated. Restless legs syndrome augmentation has been identified as a significant long-term treatment complication for pramipexole more than pregabalin and possibly for all dopaminergic agents more than α2δ ligands. Therefore, special monitoring for augmentation is required for all dopaminergic medications as well as tramadol. Other drugs also require special safety monitoring: cabergoline, pergolide, oxycodone, methadone, tramadol, carbamazepine, and valproic acid. Finally, we also highlighted gaps and needs for future clinical research and studies of restless legs syndrome. © 2018 International Parkinson and Movement Disorder Society.

Rate of augmentation and risk factors with long-term follow-up in Japanese patients with restless legs syndrome.

OBJECTIVES: Preventing augmentation is the critical clinical issue for RLS treatment. As for augmentation in Asian RLS patients, there have been only four studies and the follow-up durations of these studies were not long. We investigated Japanese RLS patients with longer duration of treatment in a clinical setting. METHODS: This study is a retrospective assessment of 42 RLS patients with follow-up durations of longer than 18 months (78.4 ± 29.2, range 19-139) at two urban sleep centers in Osaka, Japan from May 2004 to April 2014. RESULTS: The mean age of first visit was 63.5 ± 14.1 years old and the estimated age of RLS onset was 47.9 ± 16.5 years old. Twenty-eight out of 42 patients were female. At initial evaluation, the mean International Restless Legs Scale score (IRLS score) was 22.0 ± 5.9. Thirty-one of 42 had already visited other clinics before coming to our sleep centers, and the number of clinics visited was 1.3 ± 0.6. Augmentation developed in two patients (4.8%), and the dosage of dopamine equivalent in patients with and without augmentation was 12.5 and 18.8 mg vs. 15.8 ± 17.7 mg. In the two RLS patients with augmentation, ferritin was 113.1 and 114.1 ng/mL, respectively, and the number of clinics before coming to our sleep centers was both three. CONCLUSIONS: The augmentation rate of Japanese RLS patients from our study is low compared with previous Western and Asian studies. It might be attributable to racial difference, lower dosage of dopaminergic treatment, and the level of ferritin.

Rotigotine in Hemodialysis-Associated Restless Legs Syndrome: A Randomized Controlled Trial.

BACKGROUND: Restless legs syndrome (RLS) has been associated with insomnia, decreased quality of life, and increased morbidity and mortality in end-stage renal disease. This randomized controlled trial investigated effects of rotigotine in patients with RLS and end-stage renal disease. STUDY DESIGN: Double-blind placebo-controlled study. SETTING & PARTICIPANTS: Adults with moderate to severe RLS (International RLS Study Group Rating Scale [IRLS] ≥ 15) and Periodic Limb Movement Index (PLMI) ≥ 15 who were receiving thrice-weekly hemodialysis enrolled from sites in the United States and Europe. INTERVENTION: Following randomization and titration (≤21 + 3 days) to optimal-dose rotigotine (1-3mg/24 h) or placebo, patients entered a 2-week maintenance period. Polysomnography was performed at baseline and the end of maintenance. OUTCOMES & MEASUREMENTS: Primary efficacy outcome: reduction in PLMI, assessed by ratio of PLMI at end of maintenance to baseline. Secondary/other outcomes (P values exploratory) included mean changes from baseline in PLMI, IRLS, and Clinical Global Impression item 1 (CGI-1 [severity of illness]) score. RESULTS: 30 patients were randomly assigned (rotigotine, 20; placebo, 10); 25 (15; 10) completed the study with evaluable data. Mean (SD) PLMI ratio (end of maintenance to baseline) was 0.7±0.4 for rotigotine and 1.3±0.7 for placebo (analysis of covariance treatment ratio, 0.44; 95% CI, 0.22 to 0.88; P=0.02). Numerical improvements were observed with rotigotine versus placebo in IRLS and CGI-1 (least squares mean treatment differences of -6.08 [95% CI, -12.18 to 0.02; P=0.05] and -0.81 [95% CI, -1.94 to 0.33; P=0.2]). 10 of 15 rotigotine and 2 of 10 placebo patients were CGI-1 responders (≥50% improvement). Hemodialysis did not affect unconjugated rotigotine concentrations. The most common adverse events (≥2 patients) were nausea (rotigotine, 4 [20%]; placebo, 0); vomiting (3 [15%]; 0); diarrhea (1 [5%]; 2 [20%]); headache (2 [10%]; 0); dyspnea (2 [10%]; 0); and hypertension (2 [10%]; 0). LIMITATIONS: Small sample size and short duration. CONCLUSIONS: Rotigotine improved periodic limb movements and RLS symptoms in the short term among ESRD patients requiring hemodialysis in a small-scale study. No dose adjustments are necessary for hemodialysis patients.

Bidirectional triggering association between migraine and restless legs syndrome: A diary study.

OBJECTIVE: Migraine is comorbid with restless legs syndrome (RLS). However, the temporal association between these two episodic disorders remains elusive. The current study investigated the temporal relationship between migraine and RLS attacks. METHODS: Migraine patients with RLS were recruited from a headache clinic. Patients with symptomatic RLS, RLS mimics, daily headaches, or daily RLS attacks were excluded. The patients recorded their headaches and RLS attacks for two weeks in a diary. The severity of each headache or RLS attack was rated on a four-point (0-3) Likert scale. Logit-normal, random-effects models were employed to estimate the odds ratios (ORs) for the temporal association between migraine and RLS attacks. RESULTS: Thirty migraine patients with RLS (28 F/2 M, mean age 35.5 ± 9.0 years) completed the study. On the basis of 420 daily diary records, migraine attacks were associated with subsequent RLS attacks occurring on the same and next nights (OR = 6.94, 95% confidence interval (CI) = 4.39-11.0 and OR = 3.00, CI = 1.92-4.68; both ITALIC! p < 0.001). RLS attacks were associated with subsequent migraine attacks only on Day 1 (OR = 1.97 (CI = 1.3-2.98; ITALIC! p = 0.01). Overall, the frequencies of migraine and RLS attacks in two weeks were correlated (Spearman's correlation = 0.56, ITALIC! p = 0.001). CONCLUSIONS: Our study results showed a bidirectional triggering association between migraine and RLS attacks. The association was stronger and lasted longer for migraine triggering subsequent RLS than that for vice versa.

Assessment of sleep-related disorders in children with sickle cell disease.

Sleep-related disorders (SRDs) are common in sickle cell disease, however, identification may be time-consuming. Simultaneous survey of multiple SRDs utilizing a simplified instrument would facilitate screening. A simplified questionnaire investigating SRDs [sleep-disordered breathing (SDB), restless legs syndrome (RLS), insomnia, parasomnias, and daytime effects of disrupted sleep] was administered to 2-18-year-old children with sickle cell disease. One hundred participants completed this 5-7 minute survey without difficulties: 54 awoke unrefreshed, 41 had short-term insomnia, 30 had sleep-maintenance insomnia, 21 had chronic sleep-onset insomnia, 54 had chronic habitual snoring and 11 met the criteria for RLS. Sleep-maintenance insomnia was associated with increased body mass index (BMI) (p = 0.001), and chronic sleep-onset insomnia was associated with higher hemoglobin (Hb) levels (p = 0.04). Survey-reported symptoms of SRDs were significantly higher than that reported in the general pediatric population. A fast and simplified SRD survey is feasible and suggests a high prevalence of SRDs in children with sickle cell disease.

Gender medicine and sleep disorders: from basic science to clinical research.

Several pivotal differences in sleep and sleep disorders are recognized between women and men. This is not only due to changes in hormonal balance during women's reproductive life, such as in pregnancy and menopause. Women are more likely to report insomnia and non-specific symptoms of apneas, such as fatigue or mood disturbance, compared to men. Thus, it is important for clinicians and researchers to take sex and gender differences into account when addressing sleep disorders in order to acknowledge the biology unique to women. We present a narrative review that delves into the primary sleep disorders, starting from basic science, to explore the impact of gender differences on sleep and the current status of research on women's sleep health.

A Historical Overview of the Role of Benzodiazepines including Clonazepam in the Treatment of Adult Restless Legs Syndrome and Periodic Limb Movements in Sleep.

In a recent survey of 16,694 people receiving treatment for Restless Legs Syndrome (RLS), approximately 25% were treated with benzodiazepines either singly or in combination with other RLS treatments. Because of the large number of people receiving benzodiazepines for treatment of RLS, we conducted a historical overview of the therapeutic role of benzodiazepines in RLS and its associated condition Periodic Limb Movements in Sleep (PLMS). We found 17 articles on the use of clonazepam in RLS, PLMS, or both, 3 on triazolam and PLMS, 1 on alprazolam and RLS, 1 on temazepam and PLMS, and 1 on nitrazepam and PLMS. The order of benefit of benzodiazepines from the summarized literature is Sleep>RLS>PLMS and arousals > PLMS. Most of the studies on clonazepam employed dosages of 0.5-2.0 mg. Dosages of 3 or 4 mg caused lethargy, somnolence and confusion. An epidemiological study on the therapy of RLS suggests that treatment of RLS with most types of RLS medications including benzodiazepines in combination with other RLS therapies lowers the future cardiovascular risk associated with RLS. The major effect of benzodiazepines is through potentiation of the effect of GABA on the GABA A receptor. Neuroimaging studies suggest that GABA is altered either positively or negatively in various brain regions in RLS and genetic studies suggest that there are alterations in the GABA receptor in RLS. These results suggest that medications with different GABAergic mechanisms such as tiagabine (Gabitril) or others should be investigated in RLS for their possible therapeutic benefit. Highlights: Benzodiazepines are frequently used as therapy in Restless Legs Syndrome (RLS) and Periodic Limb Movements in Sleep. The order of benefit is Sleep>RLS>PLMS and arousals > PLMS. For clonazepam dosages of 0.5 mg-2.0 mg/day are most frequently employed. Benzodiazepines exert their therapeutic effect through GABA-ergic mechanisms.

Efficacy and Safety of Acupuncture for Restless Legs Syndrome in Patients with End-Stage Renal Disease: A Randomized-Controlled Trial at Hospital-Based Hemodialysis Center.

Background: Restless legs syndrome (RLS) is frequent in patients with hemodialysis (HD) and occurs predominantly in its most severe forms. The study was conducted to evaluate the efficacy and safety of acupuncture for RLS in patients with end-stage renal disease (ESRD) at hospital-based HD center. Methods: This single-blind, randomized controlled trial was performed on patients with HD and RLS who were randomly assigned to the experimental group and control group. Data were collected using the International Restless Legs Syndrome Rating Scale (IRLSRS), Insomnia Severity Index (ISI), and heart rate variability (HRV) records at baseline, after the therapeutic course (12 times/4 weeks), and 1-week follow-up. Result: A total of 47 patients were evaluated with IRLSRS score from 11 to 30 in this study. There were 41 patients enrolled in the study based on inclusion/exclusion criteria and allocated randomly into two groups. A total of 35 participants completed the trial, including 18 subjects in the experimental group and 17 subjects in the control group. The comparison of IRLSRS and ISI showed a significant reduction between two groups after acupuncture treatment (p = 0.002, p = 0.003). The ISI after 1-week follow-up also revealed significant decrease (p = 0.003). This HRV results showed that high frequency (HF%) increased significantly (p = 0.021) and low frequency (LF%) decreased significantly in the acupuncture group (p = 0.021). The generalized estimating equation showed that the IRLSRS improved by 2.902 points (p < 0.001) in the acupuncture group compared with the control group and by 1.340 points (p = 0.003) after 1-week follow-up. There were no adverse effects observed during HD in this study. Discussion: The authors conclude that acupuncture could effectively improve the symptoms of RLS significantly. The results from this study provide clinical evidence on the efficacy and safety of acupuncture to treat the patients with RLS at the HD center.

Restless legs syndrome is prevalent in adults with cystic fibrosis and impacts sleep quality.

BACKGROUND: Restless legs syndrome (RLS) is a sensorimotor disorder that is prevalent in chronic inflammatory conditions. RLS prevalence, risk factors, and impact on sleep in CF have not been extensively characterized to date. METHODS: An initial cohort was examined, including 75 persons with CF (PwCF) and 75 control subjects, to look at the prevalence and severity of RLS. A second validation cohort of 191 PwCF was then enrolled from two CF centers to examine risk factors for RLS. A diagnosis of RLS was made according to the International RLS Study Group (IRLSSG) criteria. Sleep quality was identified using the Pittsburgh sleep quality index (PSQI). Epworth sleepiness scale (ESS) was used to measure daytime sleepiness. We then analyzed laboratory and clinical risk factors and sleep symptoms for potential risk factors for RLS. RESULTS: In the initial cohort, 36 % of PwCF had RLS, and 9 % of these had significant RLS. In contrast, only 15 % of controls had RLS, and none had significant RLS. In the second larger validation cohort with 191 subjects, a comparable prevalence of RLS was identified. Higher hemoglobin A1c, use of SSRI/SNRI medications, worse PSQI and ESS sleep quality scores, lower lung function, and higher antibiotic usage were significantly associated with a diagnosis of RLS. By multivariate multinominal logistic regression analysis, higher HbA1c and worse PSQI global sleep quality scores were independent predictors of significant RLS. CONCLUSIONS: RLS is highly prevalent in CF. Higher HbA1c and poor sleep quality, signified by higher PSQI, were each independent predictors of RLS.

Comparison the effect of valerian and gabapentin on RLS and sleep quality in hemodialysis patients: A randomized clinical trial.

INTRODUCTION: This study aimed to compare the effect of valerian and gabapentin on restless legs syndrome (RLS) and sleep quality in HD patients. METHODS: In this cross over clinical trial study, 40 HD patients allocated into a valerian and gabapentin group. In the first phase of the study, Group A received valerian and Group B received gabapentin 1 h before bedtime for 1 month. In the second phase, the two groups' treatment regimen was swapped. After a 1-month washout period, the same process was repeated on the crossover groups. RESULTS: After the first phase, the mean score of RLS was lower in the gabapentin group. But there was no statistically significant difference between the two groups in terms of sleep quality score before and after the first and second interventions. CONCLUSION: Gabapentin is more effective than valerian in improving RLS, but both are equally effective in improving sleep quality.

Circadian rhythm in restless legs syndrome.

Restless legs syndrome (RLS) is a sensorimotor disorder with a obvious circadian rhythm, as its symptoms often occur or worsen only in the evening or at night. The mechanisms behind the rhythms of RLS have not yet been fully elucidated. This review explores possible causes for the circadian fluctuations of the symptomatology, including the levels of iron, dopamine, melatonin, melanocortin, and thyroid-stimulating hormone in the brain, as well as conditions such as peripheral hypoxia and microvascular function disorders. The metabolic disturbances of the substances above can create a pathological imbalance, which is further aggravated by physiological fluctuations of circadian rhythms, and results in the worsening of RLS symptoms at night. The review concludes with the suggestions for RLS treatment and research directions in the future.

Restless legs syndrome in multiple sclerosis patients: Prevalence, impact, and association with disease-modifying therapies in a Saudi Arabian pilot study.

BACKGROUND: Restless legs syndrome (RLS) emerges as a notable sleep disorder characterized by distressing sensations within the lower extremities. Its prevalence appears to be higher among patients afflicted with multiple sclerosis (MS) compared to the general population. Despite this observation, the understanding of the intricacies of RLS and its repercussions within the context of MS patients in Saudi Arabia remains limited. METHODS: Employing a cross-sectional design, a comprehensive investigation was undertaken at King Fahad Armed Forces Hospital in Jeddah, Saudi Arabia, spanning from November 2021 to March 2022. A cohort of 66 individuals diagnosed with MS was recruited and subjected to an assessment for RLS employing the revised diagnostic criteria outlined by the International Restless Legs Syndrome Study Group (IRLSSG). Furthermore, the Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, and Sleepiness Scale were employed to gage the extent of RLS's impact on sleep quality and daily functioning. RESULTS: The prevalence of RLS amidst the MS cohort was determined to be 30.4%. An observable association was discerned between RLS presence and higher scores on the Expanded Disability Status Scale (p < 0.001), along with diminished sleep quality scores (p < 0.001) and elevated fatigue scores based on IRLSSG criteria (p < 0.001). Within the studied MS cases, 98.5 % exhibited the relapsing-remitting subtype. Further investigation demonstrated that patients treated with Fingolimod or Ocrevus presented normal IRLSSG scores, whereas those undergoing Rituximab treatment manifested an even distribution between normal and moderate scores. Correspondingly, patients receiving interferons showcased 72.2 % with normal scores and 27.8 % with mild scores. Notably, a statistically significant variance in IRLSSG scores was observed when contrasting Fingolimod and Aubagio treatments (P < 0.001). CONCLUSION: The presence of RLS as a comorbidity in MS patients within the Saudi Arabian context emerges as a significant finding, exerting a discernible detrimental influence on both disability status and sleep quality. This study underscores the need for further investigations aimed at unraveling the intricate pathophysiological underpinnings, identification of risk factors, and exploration of therapeutic modalities for RLS in this population. Furthermore, additional research endeavors are warranted to elucidate the diverse impact of various disease-modifying therapies on clinical outcomes.

Why the worsening at rest and worsening at night criteria for Restless Legs Syndrome are listed separately: review of the circadian literature on RLS and suggestions for future directions.

The field of circadian research on Restless Legs Syndrome (RLS) and periodic limb movements (PLMs) is reviewed in general. RLS has five obligatory criteria for diagnosis: (1) an urge to move the legs often accompanied by uncomfortable leg sensations; (2) symptoms are worse at rest, i.e., lying or sitting; (3) there is a least partial and temporary relief of symptoms by activity, e.g., walking or stretching or bending the legs; (4) symptoms are worse later in the day or at night; and (5) mimics of RLS such as leg cramps and positional discomfort should be excluded by history and physical. In addition, RLS is frequently accompanied by PLMs, either periodic limb movements of sleep (PLMS) as determined by polysomnography or periodic limb movements while awake (PLMW) as determined by the suggested immobilization test (SIT). Since the criteria for RLS were based upon clinical experience only, an early question after the development of the criteria was whether criteria 2 and 4 were the same or different phenomena. In other words, were RLS patients worse at night only because they were lying down, and were RLS patients worse lying down only because it was night? Early circadian studies performed during recumbency at different times of the day suggest that the uncomfortable sensations, PLMS, and PLMW as well as voluntary movement in response to leg discomfort follow a similar circadian pattern with worsening at night independent of body position and independent of sleep timing or duration. Other studies demonstrated that RLS patients get worse when sitting or lying down independent of the time of day. These studies as a whole suggest that the worsening at rest and the worsening at night criteria for RLS are related but separate phenomena and that criteria 2 and 4 for RLS should be kept separate based upon the circadian studies, as had been the case previously based upon clinical grounds alone. To more fully prove the circadian rhythmicity of RLS, studies should be conducted to see if bright light shifts the signs and symptoms of RLS to a different circadian time in concert with circadian markers.

The prevalence of and risk factors for restless legs syndrome: A nationwide study.

Objectives: Restless legs syndrome (RLS) is a neglected diagnosis, and most individuals with RLS do not access effective therapies. There has yet to be a nationwide study of the prevalence of and associated risk factors for RLS in Saudi Arabia. Materials and methods: A population-wide survey was administered to Saudi Arabian adults to assess RLS prevalence and its association with other clinical and demographic variables. RLS was defined according to 2012 IRLSSG Diagnostic Criteria. Persistent RLS was defined as symptoms occurring more than a few nights each week, and RLS causing significant daytime impairment was defined as symptoms causing "severe" excessive daytime sleepiness measured by the Epworth Sleepiness Scale. Associations were evaluated using univariate analyses and binary logistic regression. Results: 10,106 individuals completed the survey. Persistent RLS was reported in 11.9% of participants, which caused significant daytime impairment in 1.2% of participants. In multivariable analysis, younger age (OR 0.96, 95% CI 0.95-0.97; p < 0.001), tobacco smoking (OR 1.28, 95% CI 1.07-1.53; p = 0.008), anxiety (OR 1.34-1.42; p < 0.05), and moderate to severe depressive symptoms (OR 1.52-2.40; p < 0.01) were associated with persistent RLS. Younger age (OR 0.96, 95% CI 0.93-0.99; p = 0.015), female gender (OR 2.28, 95% CI 1.32-3.94; p = 0.003), and moderately severe to severe depressive symptoms (OR 13.59 and 26.7, respectively; p < 0.001) were independently associated with RLS causing significant daytime impairment. Conclusion: RLS is common in adults in Saudi Arabia and is often co-morbid with moderate to severe depressive symptoms. Both RLS and depression represent a silent epidemic in Saudi Arabia requiring active inquiry by all healthcare workers to reduce their burden and impact.

Restless legs syndrome and hypertension in men and women: a propensity score-matched analysis.

OBJECTIVE: To evaluate the association between restless legs syndrome (RLS) and hypertension in men and women based on a community-based cohort of middle-aged and elderly participants. METHODS: This cross-sectional observational study enrolled 4080 participants from the Sleep Heart Health study (SHHS). RLS was defined by positive responses on a self-administered questionnaire assessing the four diagnostic criteria, with symptoms occurring at least five times per month and associated with at least moderate distress. Hypertension was defined as SBP ≥140 mmHg, DBP ≥90 mmHg, or current use of antihypertensive medication. Propensity score-matched (PSM) inverse probability treatment weighting (IPTW) analyses and multivariable logistic regression were used to examine the relationship between RLS and hypertension. RESULTS: RLS was present in 6.8% of women (n = 152) and 3.2% of men (n = 59). In the primary cohort analysis, the odds ratio (OR) for hypertension was 1.60 [95% confidence interval (CI) 1.19-2.16, p < 0.001] for participants with RLS compared to those without RLS. In the PSM analyses, the OR for hypertension was 1.66 (95% CI 1.09-2.54, p = 0.019) for participants with RLS compared to those without RLS. In sex subgroup analyses, the association between RLS and hypertension persisted in women. In the PSM cohort, the ORs for hypertension were 1.67 (95% CI 1.01-2.81, p = 0.048) and 1.85 (95% CI 0.75-4.75, p = 0.191) in women and men, respectively. Similar results were found in IPTW cohort. CONCLUSIONS: This study revealed a positive association between RLS and hypertension in a community-based population; in sex subgroup analyses, the association persisted in women.

Optimal Contact Position of Subthalamic Nucleus Deep Brain Stimulation for Reducing Restless Legs Syndrome in Parkinson's Disease Patients: One-Year Follow-Up with 33 Patients.

Objectives: To determine the short- and medium-term therapeutic effects of subthalamic nucleus (STN) deep brain stimulation (DBS) on restless legs syndrome (RLS) in patients with Parkinson's disease (PD) and to study the optimal position of activated contacts for RLS symptoms. Methods: We preoperatively and postoperatively assessed PD Patients with RLS undergoing STN-DBS. Additionally, we recorded the stimulation parameters that induced RLS or relieved RLS symptoms during a follow-up. Finally, we reconstructed the activated contacts' position that reduced or induced RLS symptoms. Results: 363 PD patients were enrolled. At the 1-year follow-up, we found that the IRLS sum significantly decreased in the RLS group (preoperative 18.758 ± 7.706, postoperative 8.121 ± 7.083, p < 0.05). The results of the CGI score, MOS sleep, and RLS QLQ all showed that the STN-DBS improved RLS symptoms after one year. Furthermore, the activated contacts that relieved RLS were mainly located in the central sensorimotor region of the STN. Activated contacts in the inferior sensorimotor part of the STN or in the substantia nigra might have induced RLS symptoms. Conclusions: STN-DBS improved RLS in patients with PD in one year, which reduced their sleep disorders and increased their quality of life. Furthermore, the central sensorimotor region part of the STN is the optimal stimulation site.

Prevalence of insomnia and restless legs syndrome in patients with upper airway stimulation therapy and effects on treatment outcomes.

OBJECTIVE: This study aims to explore the prevalence of insomnia and restless legs syndrome (RLS) and the possible effects of these conditions on treatment adherence and outcomes in patients with upper airway stimulation (UAS) therapy for the treatment of obstructive sleep apnea. METHODS: Consecutive patients who underwent UAS system implantation were retrospectively studied. Patients without insomnia or RLS, insomnia, RLS, and both insomnia and RLS were compared. The apnea-hypopnea index (AHI), in-lab UAS titration data, Epworth Sleepiness Scale (ESS), and adherence to UAS therapy were compared. RESULTS: Sixty-four patients who had UAS implantation and completed post-implant in-lab UAS titration were identified. Insomnia was present in 47%, RLS in 28%, and both insomnia and RLS in 14%. During in-lab titration, the AHI improved for all groups and did not differ across groups. The arousal index on in-lab titration was higher in patients with both RLS and insomnia compared to those without these conditions. At the time of the in-lab titration, the hours of UAS therapy usage were reduced for patients with RLS (4.7 ± 1.9 h/night, p = 0.027) compared to those without RLS (6.0 ± 2.0 h/night). The ESS was higher in patients with RLS compared to those without RLS at in-lab titration. CONCLUSION: Insomnia and RLS are common in patients using UAS therapy. A decrease in UAS usage and higher ESS were present in patients with RLS. Further research evaluating the long-term effects of insomnia and RLS in UAS therapy usage and benefit is needed.