Prevalence of restless legs syndrome among native South Americans residing in coastal and mountainous areas

Non-motor symptoms in patients with amyotrophic lateral sclerosis: current state and future directions

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by the progressive degeneration of both upper and lower motor neurons. A defining histopathological feature in approximately 97% of all ALS cases is the accumulation of phosphorylated trans-activation response (TAR) DNA-binding protein 43 protein (pTDP-43) aggregates in the cytoplasm of neurons and glial cells within the central nervous system. Traditionally, it was believed that the accumulation of TDP-43 aggregates and subsequent neurodegeneration primarily occurs in motor neurons. However, contemporary evidence suggests that as the disease progresses, other systems and brain regions are also affected. Despite this, there has been a limited number of clinical studies assessing the non-motor symptoms in ALS patients. These studies often employ various outcome measures, resulting in a wide range of reported frequencies of non-motor symptoms in ALS patients. The importance of assessing the non-motor symptoms reflects in a fact that they have a significant impact on patients' quality of life, yet they frequently go underdiagnosed and unreported during clinical evaluations. This review aims to provide an up-to-date overview of the current knowledge concerning non-motor symptoms in ALS. Furthermore, we address their diagnosis and treatment in everyday clinical practice.

Worldwide estimation of restless legs syndrome: a systematic review and meta-analysis of prevalence in the general adult population

This systematic review, meta-analysis and meta-regression assessed the prevalence of restless legs syndrome (RLS) in the general adult population. Studies identified in Scopus, PubMed, Web of Science, and PsycInfo between January 2000 and February 2022 were included if they used a case-control or cross-sectional design and reported data regarding the prevalence of RLS. The protocol was pre-registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022300709). A total of 97 studies including 483,079 participants from 33 different countries met the eligibility criteria. The Newcastle Ottawa Scale was used to evaluate the methodological quality, and the fill-and-trim method was used to correct probable publication bias, while the jack-knife method was performed to assess small study effect. The corrected overall pooled prevalence of RLS was 3% (95% confidence interval [CI] 1.4%-3.8%). The pooled prevalence of RLS syndrome was affected by methodological quality (no data from non-respondents in the included studies), gender (higher among women), study design (lower prevalence in case-control versus cohort and cross-sectional studies). The figures for corrected pooled prevalence among men, women, alcohol consumers and smokers were 2.8% (95% CI 2%-3.7%); 4.7% (95% CI 3.2%-6.3%); 1.4% (95% CI 0%-4.2%); and 2.7% (95% CI 0%-5.3%), respectively. The prevalence among male and female participants was lower in community-based versus non-community-based studies. Moreover, the prevalence was higher in developed versus developing countries and among elders versus adults. In conclusion, RLS is a common disorder in the general adult population, with a higher prevalence in women; however, prevalence data are affected by study design and quality.

Myoclonus and other jerky movement disorders

Myoclonus and other jerky movements form a large heterogeneous group of disorders. Clinical neurophysiology studies can have an important contribution to support diagnosis but also to gain insight in the pathophysiology of different kind of jerks. This review focuses on myoclonus, tics, startle disorders, restless legs syndrome, and periodic leg movements during sleep. Myoclonus is defined as brief, shock-like movements, and subtypes can be classified based the anatomical origin. Both the clinical phenotype and the neurophysiological tests support this classification: cortical, cortical-subcortical, subcortical/non-segmental, segmental, peripheral, and functional jerks. The most important techniques used are polymyography and the combination of electromyography-electroencephalography focused on jerk-locked back-averaging, cortico-muscular coherence, and the Bereitschaftspotential. Clinically, the differential diagnosis of myoclonus includes tics, and this diagnosis is mainly based on the history with premonitory urges and the ability to suppress the tic. Electrophysiological tests are mainly applied in a research setting and include the Bereitschaftspotential, local field potentials, transcranial magnetic stimulation, and pre-pulse inhibition. Jerks due to a startling stimulus form the group of startle syndromes. This group includes disorders with an exaggerated startle reflex, such as hyperekplexia and stiff person syndrome, but also neuropsychiatric and stimulus-induced disorders. For these disorders polymyography combined with a startling stimulus can be useful to determine the pattern of muscle activation and thus the diagnosis. Assessment of symptoms in restless legs syndrome and periodic leg movements during sleep can be performed with different validated scoring criteria with the help of electromyography.

Restless legs syndrome: Over 50 years of European contribution

Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterised by an urge to move the limbs with a circadian pattern (occurring in the evening/at night), more prominent at rest, and relieved with movements. RLS is one of the most prevalent sleep disorders, occurring in 5%-10% of the European population. Thomas Willis first described RLS clinical cases already in the 17th century, and Karl-Axel Ekbom described the disease as a modern clinical entity in the 20th century. Despite variable severity, RLS can markedly affect sleep (partly through the presence of periodic leg movements) and quality of life, with a relevant socio-economic impact. Thus, its recognition and treatment are essential. However, screening methods present limitations and should be improved. Moreover, available RLS treatment options albeit providing sustained relief to many patients are limited in number. Additionally, the development of augmentation with dopamine agonists represents a major treatment problem. A better understanding of RLS pathomechanisms can bring to light novel treatment possibilities. With emerging new avenues of research in pharmacology, imaging, genetics, and animal models of RLS, this is an interesting and constantly growing field of research. This review will update the reader on the current state of RLS clinical practice and research, with a special focus on the contribution of European researchers.

Restless legs syndrome

Restless legs syndrome (RLS) is a common sensorimotor disorder characterized by an urge to move that appears during rest or is exacerbated by rest, that occurs in the evening or night and that disappears during movement or is improved by movement. Symptoms vary considerably in age at onset, frequency and severity, with severe forms affecting sleep, quality of life and mood. Patients with RLS often display periodic leg movements during sleep or resting wakefulness. RLS is considered to be a complex condition in which predisposing genetic factors, environmental factors and comorbidities contribute to the expression of the disorder. RLS occurs alone or with comorbidities, for example, iron deficiency and kidney disease, but also with cardiovascular diseases, diabetes mellitus and neurological, rheumatological and respiratory disorders. The pathophysiology is still unclear, with the involvement of brain iron deficiency, dysfunction in the dopaminergic and nociceptive systems and altered adenosine and glutamatergic pathways as hypotheses being investigated. RLS is poorly recognized by physicians and it is accordingly often incorrectly diagnosed and managed. Treatment guidelines recommend initiation of therapy with low doses of dopamine agonists or α₂δ ligands in severe forms. Although dopaminergic treatment is initially highly effective, its long-term use can result in a serious worsening of symptoms known as augmentation. Other treatments include opioids and iron preparations.

Restless legs syndrome affecting the head region: "restless head syndrome"

OBJECTIVE

Restless legs syndrome (RLS) is a well-established disease that has recently been shown to have variants affecting the arms, face, abdomen, and genital area. To our knowledge, there has been no study reporting on the RLS variant affecting the head region.

METHODS

The retrospective study reviewed a total of 460 patients who presented to Fırat University Medical School and were diagnosed as having RLS based on the International Restless Legs Syndrome Study Group (IRLSSG) criteria between June 2017 and January 2020. Of these, 18 patients that presented with head-related RLS symptoms (in addition to legs or arms) and four cases that presented with isolated head involvement were included in the study.

RESULTS

In 15 out of 18 (81.8%) patients, the restless head syndrome was accompanied by restless arm syndrome (RAS). In the remaining four (18.2%) patients, the disease involved the head region alone. The disease initially emerged in a single region in the body and gradually spread to one or multiple other regions in most patients and the symptoms were relieved by head rubbing. Serum iron level was low in 8 (36.4%) patients and normal in 14 (63.6%) patients. All the patients had normal cranial imaging and the symptoms were eliminated after dopaminergic therapy.

CONCLUSIONS

Although RLS typically involves the legs alone, it may also affect other body parts such as upper extremities, abdomen, face, and genital area. We propose that the novel RLS variant described in the present study could be termed "restless head syndrome."

Association between leg motor restlessness and depression among Chinese males living at high-altitude: the mediating role of insomnia

OBJECTIVE

Previous research has documented an association between insomnia and depression among patients with restless legs syndrome (RLS)/Willis-Ekbom disease. Given that leg motor restlessness (LMR) is closely related to RLS, the purpose of this study was to investigate the prevalence of insomnia and depression among individuals with LMR. In addition, we examined the associations among LMR, insomnia, and depression in a sample of young Chinese men living in high-altitude areas.

METHODS

Chinese military personnel working on the Qinghai Tibet Plateau (Lhasa, an altitude of 3600 m) were recruited in 2019 to complete a series of questionnaires. Participants having the urge to move their legs but not meeting the diagnostic criteria for RLS were classified as having LMR. Hierarchical linear regressions and mediational analyses using the SPSS PROCESS macro in SPSS were conducted to examine the associations among LMR, insomnia, and depression.

RESULTS

Of 196 participants, 36 (18%) had LMR. Only 1 participant was diagnosed with RLS. The proportions of participants suffering from insomnia who had LMR and did not have LMR were 44% and 22%, respectively. For depression, the proportions were 47% and 28%, respectively. Results of the hierarchical linear regressions showed that both LMR and depression were associated with increased insomnia symptoms. In addition, results from the mediational analyses indicated that the indirect effect of LMR on depression was significant and accounted for 52% of the total effect.

CONCLUSIONS

Participants with LMR had a higher prevalence of insomnia and depression compared with those without LMR. In addition, LMR was correlated with depression, and insomnia played a significant role in this co-occurrence.

Sleep and Tibialis Anterior Muscle Activity in Mice With Mild Hypoxia and Iron Deficiency: Implications for the Restless Legs Syndrome

Restless legs syndrome (RLS) is a neurological disorder that entails an urge to move with a circadian pattern during the evening/night. RLS may be accompanied by decreased sleep time and increased occurrence of periodic leg movements during sleep (PLMS), which involve bursts of tibialis anterior (TA) muscle electromyogram (EMG). Mild hypoxia and non-anemic iron deficiency, a highly prevalent nutritional deficiency, are relatively unexplored factors in RLS pathophysiology. We tested whether mice exposed to mild hypoxia, alone or in combination with non-anemic iron deficiency, show decreased sleep time particularly in the light (rest) period and increased occurrence of TA EMG phasic events similar to human PLMS. Female C57BL/6J mice were fed diets with low or normal iron for 6 months from weaning and instrumented with electrodes to record the electroencephalogram and the EMG of both TA muscles. Mice were recorded in a whole-body plethysmograph while breathing a normoxic or mildly hypoxic (15% O₂) gas mixture for 48 h. Hypoxia increased minute ventilation during sleep. The low-iron diet decreased liver and serum iron, leaving blood hemoglobin and brainstem iron levels unaffected. Hypoxia, either alone or in combination with non-anemic iron deficiency, decreased non-rapid-eye-movement (non-REM) sleep time, but this occurred irrespective of the light/dark period and was not associated with increased occurrence of TA EMG events during non-REM sleep. These results do not support the hypothesis that mild hypoxia is sufficient to cause signs of RLS, either alone or in combination with non-anemic iron deficiency, pointing to the necessity of further susceptibility factors.

Risk factors of primary and secondary restless legs syndrome among a middle-aged population in Saudi Arabia: A community-based study

INTRODUCTION:

Restless legs syndrome (RLS) is etiologically divided into primary and secondary syndromes. However, a comparative description of both types is lacking in the literature. We compared primary and secondary RLS with respect to demographic determinants, associated risk factors, and comorbidities.

METHODS:

Following a cross-sectional survey on the prevalence of RLS in a Saudi population, RLS cases were identified using the International RLS Study Group (IRLSSG) criteria. Cases were assessed with an interview-based questionnaire regarding baseline characteristics, risk factors, and comorbidities and with lower limb examinations and laboratory measurements. RLS severity was assessed using the IRLSSG Severity Rating Scale.

RESULTS:

In total, 78 patients with RLS, including 50 (64.1%) primary and 28 (35.9%) secondary cases, were examined. Of the primary cases, 35 (70%) were male; of the secondary cases, 25 (89.3%) were female (P < 0.001). Multivariate regression confirmed the association of male gender with primary RLS (odds ratio = 14.53, 95% confidence interval [2.9–75], P = 0.001). There were more dark- and black-skinned participants in the primary RLS group (38, 72%) than in the secondary group (15, 28%) (P = 0.042). Iron deficiency was observed in most (26, 92%) of the secondary cases. More severe symptoms were reported in secondary than in primary RLS cases (P < 0.05).

CONCLUSIONS:

Primary RLS is more common but less severe than secondary RLS. Male gender and ethnicity play significant roles in primary RLS, whereas female gender and iron deficiency may be the main risk factors associated with secondary RLS.

Severity and frequency of restless legs syndrome in patients with familial Mediterranean fever

Objective:

Restless legs syndrome (RLS) is a common sensory motor disorder. RLS an urge to move the extremities that may be accompanied by dysesthesias, and significantly affects quality of life of affected patients. The frequency of RLS is higher in different systemic inflammatory diseases. Familial Mediterranean fever (FMF) is an inherited inflammatory disease characterized by attacks of polyserositis, arthritis, and fever. The prevalence of RLS in patients with FMF is unknown. This study aimed to evaluate the prevalence rate of RLS in a sample of patients with FMF and compare this prevalence with that of a matched normal population.

Method:

A total of 60 patients with FMF and 60 healthy controls were studied. All participants underwent a neurological examination. Diagnostic criteria as proposed by the International Restless Legs Syndrome Study Group (IRLSSG) were used to define RLS. The IRLSSG rating scale for the severity of RLS was applied to determine the severity of symptoms.

Results:

The prevalence of RLS was not significantly different between patients and controls. Although the mean International Restless Legs Syndrome Rating Scale (IRLSRS) scores tended to be higher in patients compared with controls, this difference was not significant. When each item of the severity scale was compared between the two groups, significantly higher scores were found in some items of the IRLSRS in patients with FMF compared with controls.

Conclusion:

According to this result, RLS symptoms in patients with FMF were more frequent and lasted longer than those in controls.

Iron and restless legs syndrome: treatment, genetics and pathophysiology

In this article, we review the original findings from MRI and autopsy studies that demonstrated brain iron status is insufficient in individuals with restless legs syndrome (RLS). The concept of deficient brain iron status is supported by proteomic studies from cerebrospinal fluid (CSF) and from the clinical findings where intervention with iron, either dietary or intravenous, can improve RLS symptoms. Therefore, we include a section on peripheral iron status and how peripheral status may influence both the RLS symptoms and treatment strategy. Given the impact of iron in RLS, we have evaluated genetic data to determine if genes are directly involved in iron regulatory pathways. The result was negative. In fact, even the HFE mutation C282Y could not be shown to have a protective effect. Lastly, a consistent finding in conditions of low iron is increased expression of proteins in the hypoxia pathway. Although there is lack of clinical data that RLS patients are hypoxic, there are intriguing observations that environmental hypoxic conditions worsen RLS symptoms; in this chapter we review very compelling data for activation of hypoxic pathways in the brain in RLS patients. In general, the data in RLS point to a pathophysiology that involves decreased acquisition of iron by cells in the brain. Whether the decreased ability is genetically driven, activation of pathways (eg, hypoxia) that are designed to limit cellular uptake is unknown at this time; however, the data strongly support a functional rather than structural defect in RLS, suggesting that an effective treatment is possible.

Achievements, challenges, and future perspectives of epidemiologic research in restless legs syndrome (RLS)

In the 20 years since the initial consensus on a common definition for restless legs syndrome (RLS), over 600 scientific reports on epidemiological aspects of RLS have been published. Most are descriptive and address important issues such as prevalence, familial patterns, comorbidities, and quality of life. While the establishment of prospective cohort studies and the use of secondary data sources are rather new to RLS research, both options significantly broaden the possibilities for analysis of disease risk factors. These two options, as well as the inclusion of a broader phenotyping of individual patients, have great potential to elucidate etiologic factors for RLS and expand knowledge about this common disorder. This article summarizes achievements in the area of RLS epidemiology, describes current challenges, and highlights future perspectives in the field.

Willis-Ekbom disease is not associated with poor cardiovascular health in adults

Background

Willis-Ekbom disease (WED), also called restless legs syndrome (RLS), is a neurologic sensorimotor disease that may be associated with cardiovascular disease. Given high morbidity and mortality rates of cardiovascular disease worldwide, we assessed the relation between WED/RLS and cardiovascular health risks in a native South American population. We prospectively analyzed data from The Atahualpa Project of Ecuadorian adults aged 40 years and older. Physicians interviewed consented persons on the health behavior and health factors of the American Heart Association (AHA) for ideal cardiovascular health in adults and underwent fasting laboratory blood collection and blood pressure evaluation. Certified neurologists conducted face-to-face interviews using the International Restless Legs Syndrome Study Group (IRLSSG) field instrument. Persons testing positive for WED/RLS and age-and sex-matched controls underwent confirmatory physical examinations conducted by a neurologist and a sleep specialist to whom IRLSSG designation was blinded.

Findings

Of 665 persons, 94 (14 %) tested positive in IRLSSG; 40 (6 %) had a diagnosis of WED/RLS after neurologic examination and interview. Patients with WED/RLS were younger (53.5 vs 59.9 years, P = .001), without significant differences in sex ratios. Among AHA risk factors, only obesity was significantly more prevalent among patients with WED/RLS (42.5 % vs 23.5 %, P = .01). However, after adjustment for confounders, body mass index was not significantly associated with WED/RLS.

Conclusions

In adult Amerindians, although obesity and body mass index were associated with WED/RLS on univariate analyses, the association was not present after adjustment for confounders. No other significant associations were found between WED/RLS and AHA cardiovascular metrics.

Restless Leg Syndrome Across the Globe: Epidemiology of the Restless Legs Syndrome/Willis-Ekbom Disease

There are more than 50 epidemiologic studies measuring the prevalence of restless legs syndrome/Willis-Ekbom disease (RLS/WED) across 5 of the 6 inhabited continents (not Australia), most conducted in North America and Europe. Sufficient studies have been conducted in Asia, North America, and Europe to make inferences on RLS/WED prevalence by region. RLS/WED prevalence is thought to be highest in North America and Europe and lower in Asia. These differences across regions may be explained by cultural, environmental, and genetic factors. Future investigation is needed to determine to what extent these factors affect expression of RLS/WED according to world region.

An update on restless legs syndrome (Willis-Ekbom disease): clinical features, pathogenesis and treatment

PURPOSE OF REVIEW

In recent years, there have been a number of advances in the field of restless legs syndrome (RLS) or Willis-Ekbom disease (WED). Here, we review recent studies pertaining to the diagnosis and clinical features, pathogenesis, and treatment of RLS/WED.

RECENT FINDINGS

Recent studies have added a temporal dimension to RLS/WED epidemiology by examining both the incidence and persistence rates in different populations. Diagnostic criteria have been modified to increase sensitivity, and new guidelines take into account recently published studies of different drug classes.

SUMMARY

Recent epidemiological findings have shown that RLS/WED is a common neurological disorder that affects up to 5% of the adult population in Western countries. In moderate and severe cases, RLS/WED has a strong impact on sleep and quality of life and can involve an increased cardiovascular risk. Diagnosis is made clinically by confirming the presence of the five essential criteria. However, in difficult cases objective tests such as the multiple suggested immobilization test (m-SIT) can be used. The pathophysiology is partially known, with several risk polymorphisms (BTBD-9 (BTB (POZ) domain containing 9), MEIS-1 (Meis homeobox 1), protein tyrosine phosphatase, receptor type, D, and others) playing an important role, along with dopaminergic and iron dysfunctions. The disorder frequently requires long-term treatment with low-dose dopamine agonists or α2δ ligands. Dopamine agonists are usually effective but the main complication, RLS/WED augmentation, can arise.

Psychological distress in patients with restless legs syndrome (Willis-Ekbom disease): a population-based door-to-door survey in rural Ecuador

Background

Reported prevalence of restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED), varies from country to country, and methodologic inconsistencies limit comparison of data. Impact of RLS on quality of life and health has been studied primarily in industrialized countries, particularly Europe and the United States. Many studies have relied exclusively on self-report of symptoms or have assessed only medical populations. Recently, interest has emerged on the impact of WED in rural, underserved populations globally.

Methods

In a population-based survey conducted in rural Ecuador, we assessed the relationship of psychological distress to WED, evaluated with the Depression Anxiety Stress Scales–21. WED was diagnosed through a 2-phase method in which all residents were screened with the International Restless Legs Syndrome Study Group (IRLSSG) questionnaire and all suspected cases were subsequently confirmed through expert medical examination. WED severity was assessed with the IRLSSG rating scale.

Results

Of 665 persons (mean [SD] age, 59.5 [12.6] years; women, 386 [58%]), 76 had depression, 93 had anxiety, and 60 reported stress. Forty persons (6%) had WED, with 15 (38%) having severe disease. In a regression model adjusted for age and sex, the prevalence of depression, anxiety, and stress was about 3 times greater among persons with WED than the general population.

Conclusions

Although cross-sectional data cannot establish causation, this study shows the large behavioral health burden associated with WED in an untreated, rural population.

Prevalence of restless legs syndrome in Ankara, Turkey: an analysis of diagnostic criteria and awareness

The aim of this study was threefold: (1) to investigate the prevalence of restless legs syndrome (RLS), in Ankara, Turkey; (2) to determine the predictive values of diagnostic criteria; and (3) to determine the frequency of physician referrals and the frequency of getting the correct diagnosis. A total of 815 individuals, from randomly selected addresses, above the age of 15, were reached using the questionnaire composed of the four diagnostic criteria. Individuals who responded by answering 'yes' for at least one question were interviewed by neurologists for the diagnosis of RLS. Frequency of physician referrals and frequency of getting the correct diagnosis of RLS were also determined for patients getting the final diagnoses of RLS. Prevalence of RLS in Ankara was 5.52 %; 41.0 % of the individuals diagnosed with RLS had replied 'yes' to either one, two or three questions asked by interviewers. However, only 21.3 % of individuals who replied 'yes' to all four questions received the diagnosis of RLS. Among the patients who had the final diagnosis of RLS, 25.7 % had referred to a physician for the symptoms and 22.2 % got the correct diagnosis. The RLS prevalence in Ankara was somewhere between Western and Far East countries compatible with the geographical location. Diagnostic criteria may not be fully predictive when applied by non-physician pollsters. Physician's probability of correctly diagnosing RLS is still low.

Ethnic differences in the prevalence and predictors of restless legs syndrome between Hispanics of Mexican descent and non-Hispanic Whites in San Diego county: a population-based study

STUDY OBJECTIVES

To investigate the prevalence and predictors of RLS in Hispanics of Mexican descent (HMD) and non-Hispanic whites (NHW).

DESIGN

A population-based random digit dialing telephone questionnaire.

SETTING

San Diego County California

PARTICIPANTS

1,754 HMD and 1,913 NHW adults ≥ 18 years of age able to participate in a telephone interview in English or Spanish.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

RLS was defined by the presence of all 4 criteria of the International Restless Legs Study Group. Sleepiness was measured by the Epworth Sleepiness Scale. Acculturation was evaluated using the Short Acculturation Scale for Hispanics. Risk factors for RLS were by self-report. The survey was conducted in the subject's language of choice. RLS prevalence was significantly lower in HMD than in NHW (14.4% vs.18.3%, p = 0.002). High acculturation HMD had a significantly greater RLS prevalence than the low acculturation group (17.4% vs. 12.8%, p = 0.008). Predictors of RLS varied between HMD and NHW. Female gender (OR 1.40, 95% CI 1.04, 1.90, p = 0.027), smoking (OR 1.82, 95% CI 1.27, 2.61, p = 0.001), and acculturation (OR 1.47, 95% CI 1.10, 1.97, p = 0.009) were independent predictors of RLS in HMD, while only older age (OR 1.01, 95% CI 1.0, 1.02) was an independent predictor of RLS for NHW.

CONCLUSION

The prevalence of RLS was significantly lower in HMD than in NHW, and significantly greater in high acculturation HMD. Our data suggest that risk factors for RLS vary by race/ethnicity and acculturation is an independent risk for RLS in HMD.

Health-related quality of life and economic burden in patients with restless legs syndrome

Restless legs syndrome (RLS) is characterized by a distressing, irresistible need or urge to move the legs. It often co-exists with an uncomfortable, though not usually painful, sensation in the legs. Although clear diagnostic criteria and effective treatment options exist, RLS is generally underdiagnosed and under-treated. RLS patients often suffer from sleep disturbances that may severely disrupt normal life functioning. Furthermore, it is one of the most common neurological disorders. In this communication, we provide a systematic review of the literature on health-related quality of life (HRQoL) and health economic issues in patients suffering from RLS. RLS has a considerable impact on the HRQoL of patients, which is comparable to other neurological and chronic diseases. The most important factors contributing to the impairment of HRQoL are the severity of RLS symptoms and the associated sleep disturbances. Although little work has been published on cost-of-illness of RLS, available studies suggest that a considerable economic burden is caused by RLS. Because of the large number of patients requiring treatment and the considerable increase in the number of treatment studies performed in recent years, as well as approval of several drugs for this indication, we assume a considerable increase in treatment frequency. Very few of the RLS treatment options, however, have been evaluated for their cost-effectiveness, and further research is needed on both quality-of-life issues and the economic impact of RLS.

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

PURPOSES

Restless legs syndrome (RLS) is underdiagnosed and poorly understood by clinicians and the general public alike; accordingly, a broad literature review with information most relevant to general practice is needed to help dispel misconceptions and improve level of care.

METHODS

Specifically, this review comprehensively provides an epidemiological analysis of RLS and examines the risk factors and treatment options for RLS by compiling the findings of past RLS studies. These RLS studies were identified through a retrospective PubMed search. The epidemiological analysis was conducted by calculating a weighted mean average of all the relevant general population RLS prevalence studies, separated into geographical/racial categories.

RESULTS

A comprehensive analysis of RLS epidemiological studies finds the prevalence rate of RLS to be 5-15% in the general population with 2.5% of adults having symptoms severe enough to require medical intervention. Some of the risk factors for RLS include female gender, pregnancy, low iron levels, lower socioeconomic status, poor health, elderly age, comorbidity with Parkinson's disease, positive family history of RLS, and comorbidity with psychiatric disorders. A wide array of treatment options exist for RLS including pharmacological and nonpharmacologic interventions.

CONCLUSIONS

Clinicians' understanding of RLS enigma has recently improved due to the increased intensity of RLS research over the past decade. This review summarizes the current findings in the RLS field as well as providing guidelines for future RLS-related research.

Prevalence of restless legs syndrome in the rural town of Cassia dos Coqueiros in Brazil

OBJECTIVE

To estimate the prevalence and evaluate the characteristics and severity of restless legs syndrome (RLS) in an urban Brazilian community.

METHODS

A transversal study was conducted over an 18-month period. A neurologist conducted 1155 interviews using the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG).

RESULTS

The lifetime prevalence of RLS was found to be 6.40%. Prevalence during the last year, the last month, and the last week were found to be 5.71%, 5.36%, and 4.15%, respectively. A greater proportion of women met diagnostic criteria for RLS compared to men (OR: 2.63, CI 95%: 1.54-4.51). Furthermore, participants with low monthly family income (<$1575 USD) had a lower prevalence of disease compared to those with a high monthly family income (>$1575 USD) (OR: 2.91, CI 95%: 1.41-5.98).

CONCLUSIONS

This is the first epidemiologic study of RLS conducted in a Brazilian population. The overall prevalence of disease and the greater proportion of RLS in women found in this study are similar to the findings of other studies conducted in western countries. The association of RLS with high family income is unpublished and should be confirmed in subsequent studies.

Epidemiology of restless legs syndrome: a synthesis of the literature

Restless legs syndrome (RLS) has gained considerable attention in the recent years: nearly 50 community-based studies have been published in the last decade around the world. The development of strict diagnostic criteria in 1995 and their revision in 2003 helped to stimulate research interest on this syndrome. In community-based surveys, RLS has been studied as: 1) a symptom only, 2) a set of symptoms meeting minimal diagnostic criteria of the international restless legs syndrome study group (IRLSSG), 3) meeting minimal criteria accompanied with a specific frequency and/or severity, and 4) a differential diagnosis. In the first case, prevalence estimates in the general adult population ranged from 9.4% to 15%. In the second case, prevalence ranged from 3.9% to 14.3%. When frequency/severity is added, prevalence ranged from 2.2% to 7.9% and when differential diagnosis is applied prevalence estimates are between 1.9% and 4.6%. In all instances, RLS prevalence is higher in women than in men. It also increases with age in European and North American countries but not in Asian countries. Symptoms of anxiety and depression have been consistently associated with RLS. Overall, individuals with RLS have a poorer health than non-RLS but evidence for specific disease associations is mixed. Future epidemiological studies should focus on systematically adding frequency and severity in the definition of the syndrome in order to minimize the inclusion of cases mimicking RLS.

Restless legs syndrome

Restless legs syndrome (RLS) is characterized by a compelling, often insatiable, need to move the legs, accompanied by unpleasant sensations located mainly in the ankles and calves. Because symptoms are brought on by inactivity, distress intrudes upon everyday, sedentary activities such as plane travel, car rides, and attending school, meetings, or the theatre. Symptoms show a diurnal preference for the evening and night, so disruption of sleep onset or maintenance is particularly common. RLS is associated with both lower ratings of quality of life and higher rates of cardiovascular disease. Four common genetic loci associating to RLS have recently been identified, but the molecular pathways by which they increase risk for RLS have yet to be determined. Both sensory (RLS) and motor (periodic limb movements of sleep) symptoms are responsive to dopaminergic medications, yet clear delineation of dopaminergic pathology has not emerged. Brain iron is reduced in many, but not all, patients with RLS. First-line treatment for RLS includes agents acting at D(2) and D(3) dopamine receptors.

Restless legs syndrome in a population of northern Tanzania: a community-based study

Restless legs syndrome (RLS) is a highly prevalent movement disorder. However, prevalences seem to vary amongst different ethnicities. To date, no community-based prevalence studies on RLS have been reported from the African continent. We have conducted a community-based, door-to-door study in northern Tanzania. Over a period of 16 months, 7,654 people aged 14 years and older were screened for the RLS Essential Diagnostic Criteria. Sampling was performed according to the method of "multistage cluster sampling." People who screened positive where reinterviewed and physically examined by a specialist neurologist. During the screening phase, 10 people answered "yes" to at least one of the screening questions. After reinterviewing those people, the result was confirmed in five people only. After careful re-evaluation of the results, only one person was diagnosed with RLS. Because of methodological limitations a definite prevalence may only be calculated from larger population-based studies of different African ethnicities with screening questions adapted to the cultural context.

Economic and human costs of restless legs syndrome

Restless legs syndrome (RLS) is a common and often underestimated neurological disorder, with a prevalence ranging from approximately 2.5% to 10% in Western industrialized countries. The aim of the present study was to summarize the research findings on the human and economic costs associated with RLS in populations without any co-morbidities or potentially confounding health conditions. A further objective was to identify studies on the cost effectiveness of RLS treatments. A systematic literature search was performed. Two researchers independently assessed the relevance of each publication. Studies published before August 2008 were included if they assessed quality of life in patients suffering from RLS, determined total or patient-related costs attributable to RLS, and/or evaluated the cost effectiveness of treatment options for RLS. A total of 725 references were identified, including 100 full-text articles. Fifteen of these publications met all of the selection criteria and were included in the present review. Seven abstracts that focused on the economic burden of RLS and/or the cost effectiveness of different treatment strategies in RLS patients were also included. RLS was associated, in the included studies, with reductions in quality of life similar to those seen in patients with other chronic conditions. The cost-of-illness studies were heterogeneous but indicated that RLS was associated with a substantial economic burden, resulting in high direct and indirect costs to society. Although effective and cost-effective treatments appear to be available, further research is warranted, especially regarding the economic burden of RLS and the cost effectiveness of available treatment options.

Restless legs syndrome in patients on hemodialysis: symptom severity and risk factors

Background and Purpose

Restless legs syndrome (RLS) is a sleep disorder that frequently occurs in dialysis patients, which disturbs the sleep and reduces the quality of life. The aim of this study was to determine the risk factors for RLS in dialysis patients.

Methods

Patients who visited any of four outpatient dialysis clinics between September 2005 and May 2006 were included in this study. The diagnosis of RLS and the severity assessment were made using the criteria described by the International Restless Legs Syndrome Study Group. We collected basic demographic data, clinical information, and laboratory findings, and then analyzed their association with various aspects of RLS using univariate and multivariate analyses.

Results

RLS was present in 46 (28.0%) of 164 dialysis patients. We found no significant risk factor for inducing RLS. The predialysis serum blood urea nitrogen (BUN) level in the dialysis patients with RLS was significantly correlated with RLS symptom severity.

Conclusions

Predialysis BUN is related to RLS symptom severity. Further studies on the underlying mechanism are needed.

[Restless-legs syndrome]

Restless-legs syndrome (RLS) is a sensorimotor disorder, characterized by an irresistible urge to move the legs usually accompanied or caused by uncomfortable and unpleasant sensations. It begins or worsens during periods of rest or inactivity, is partially or totally relieved by movements and is exacerbated or occurs at night and in the evening. RLS sufferers represent 2 to 3% of the general population in Western countries. Supportive criteria include a family history, the presence of periodic-leg movements (PLM) when awake or asleep and a positive response to dopaminergic treatment. The RLS phenotypes include an early onset form, usually idiopathic with a familial history and a late onset form, usually secondary to peripheral neuropathy. Recently, an atypical RLS phenotype without PLM and l-DOPA resistant has been characterized. RLS can occur in childhood and should be distinguished from attention deficit/hyperactivity disorder, growing pains and sleep complaints in childhood. RLS should be included in the diagnosis of all patients consulting for sleep complaints or discomfort in the lower limbs. It should be differentiated from akathisia, that is, an urge to move the whole body without uncomfortable sensations. Polysomnographic studies and the suggested immobilization test can detect PLM. Furthermore, an l-DOPA challenge has recently been validated to support the diagnosis of RLS. RLS may cause severe-sleep disturbances, poor quality of life, depressive and anxious symptoms and may be a risk factor for cardiovascular disease. In most cases, RLS is idiopathic. It may also be secondary to iron deficiency, end-stage renal disease, pregnancy, peripheral neuropathy and drugs, such as antipsychotics and antidepressants. The small-fiber neuropathy can mimic RLS or even trigger it. RLS is associated with many neurological and sleep disorders including Parkinson's disease, but does not predispose to these diseases. The pathophysiology of RLS includes an altered brain-iron metabolism, a dopaminergic dysfunction, a probable role of pain control systems and a genetic susceptibility with nine loci and three polymorphisms in genes serving developmental functions. RLS treatment begins with the elimination of triggering factors and iron supplementation when deficient. Mild or intermittent RLS is usually treated with low doses of l-DOPA or codeine; the first-line treatment for moderate to severe RLS is dopaminergic agonists (pramipexole, ropinirole, rotigotine). In severe, refractory or neuropathy-associated RLS, antiepileptic (gabapentin, pregabalin) or opioid (oxycodone, tramadol) drugs can be used.