Restless Legs Syndrome Symptoms in Primary Care

Diurnal cycle influences peripheral and brain iron levels in mice

Iron movement between organ pools involves a dynamic equilibrium of iron efflux and uptake, and homeostatic mechanisms are likely involved in providing iron to cells and organs when required. Daily iron levels in the plasma pool fluctuate with the diurnal cycle, but clear explanations regarding the objectives and regulation of the flux are lacking. The association between diurnal cycle and iron flux is relevant in the disease of restless legs syndrome (RLS), where individuals display diurnal deficits in motor control, have impaired brain iron metabolism, and perhaps altered iron uptake from the plasma pool. The goal of the present study was to examine diurnal variations in peripheral and regional brain iron to evaluate iron flux between organs in iron-sufficient and iron-deficient mice. In mice fed control diet, liver iron was elevated 30-40%, and plasma iron was reduced 20-30% in the active dark period compared with the inactive light phase. Dietary iron deficiency eliminated this variation in liver iron in male and female mice and in plasma iron in male mice. Reductions in ventral midbrain and nucleus accumbens iron and ferritin were apparent in iron-deficient mice during both diurnal phases, but only during the light phase was an approximately 25% reduction in whole brain iron observed, suggesting different brain iron requirements between phases. These data demonstrate that iron flux between organs is sensitive to diurnal regulatory biology. Importantly, variations in brain iron may have temporal implications regarding neural functioning and may contribute to the diurnal cycle-dependent symptoms of RLS.

Restless legs syndrome: pathophysiology, diagnosis and treatment

Restless legs syndrome (RLS) is clinically defined by the presence of (i) an urge to move the legs with or without an actual paraesthesia; (ii) a worsening of symptoms with inactivity; (iii) improvement with activity; and (iv) a worsening of symptoms in the evening and at night. Patients may use a variety of semantic phrases to describe their symptoms but all must have an urge to move. Most people with RLS also have periodic limb movements during sleep, although this is not part of the clinical diagnostic criteria. RLS is very common. About 10% of all Caucasian populations have RLS, although it may be mild in the majority of cases. Women generally outnumber men by about 2:1. As a general rule, RLS severity worsens through the first seven to eight decades of life, but may actually lessen in old age. The aetiology of RLS is only partly understood. There is a strong genetic component, and several genetic linkages and three causative genes have been identified worldwide. Several medical conditions, including renal failure, systemic iron deficiency and pregnancy, and possibly neuropathy, essential tremor and some genetic ataxias, are also associated with high rates of RLS. In all cases to date, the actual CNS pathology of RLS demonstrates reduced iron stores, in a pattern that suggests that the homeostatic control of iron is altered, not just that there is not enough iron entering the brain. The relationship between reduced CNS iron levels and the clinical phenotype or treatment response to dopaminergics is not known but generates promising speculation. Treatment of RLS is usually rewarding. Most patients respond robustly to dopamine receptor agonists. Over time, response may lessen, or the patients may develop 'augmentation', whereby they have a worsening of symptoms, usually in the form of an earlier onset. Other treatment options include gabapentin, or similar antiepileptic drugs, and opioids. High-dose intravenous iron is a promising but still experimental approach.

Intradialytic aerobic exercise training ameliorates symptoms of restless legs syndrome and improves functional capacity in patients on hemodialysis: a pilot study

We present the first study on the influence of exercise training on restless legs syndrome (RLS) in patients on hemodialysis (HD). Restless legs syndrome has been treated pharmacologically with satisfactory results; however, side effects and rebound phenomena have been reported. Intradialytic exercise training effectively counteracts uremia-induced catabolism; nevertheless, it remains unknown whether patients with RLS undergoing HD benefit from such programs. The aims of the current study were to evaluate the effect of 16-weeks aerobic exercise training in the severity of RLS and in the functional capacity and the quality of life of patients with RLS on HD. Fourteen patients on HD (four female, mean age 59 +/- 16 years) with untreated RLS were assigned, according to their will, to either the exercise group (Ex-group, n = 7), and participated in a 16-week supervised intradialytic aerobic exercise training, or to the control group (Con-group, n = 7), and continued usual activities. Primary aim was to compare the International RLS (IRLS) study group rating scale, functional ability, and quality of life in baseline and the end of the 16 weeks. Exercise training reduced IRLS score by 42% (p = 0.02). Furthermore, it significantly improved indices of functional ability (p = 0.02), exercise capacity (p = 0.01), quality of life (p = 0.03), and sleep quality (p = 0.01). In the Con-group no changes were observed. In conclusion, aerobic exercise training is safe and efficacious in reducing RLS symptoms and improving quality of life in patients with RLS on HD.

Appropriate use of dopamine agonists and levodopa in restless legs syndrome in an ambulatory care setting

BACKGROUND

Dopaminergic agents are the mainstay therapy for the management of restless legs syndrome (RLS). There are no clear guidelines on RLS management, and no study has evaluated the appropriate use of dopaminergic agents in RLS.

OBJECTIVE

To evaluate the appropriateness of use of dopaminergic agents in RLS management in an ambulatory care setting based on the most current scientific evidence.

METHODS

A retrospective drug utilization evaluation was conducted in patients who received levodopa or dopamine agonist for RLS from July 1, 2006, to July 31, 2007. Patients' medical records were reviewed and data were collected on demographics; comorbidities; laboratory values; doses of levodopa or dopamine agonists; prescribing physician's specialty; and use of alcohol, tobacco, and caffeine.

RESULTS

A total of 27 patients were included in the study for data collection and analysis. Twenty-two (81%) patients were on levodopa and 5 (19%) were on ropinirole. RLS severity was documented in only 2 (7%) patients. Serum ferritin levels and transferrin-iron saturation (Tsat) percentages were not obtained in 18 (67%) and 20 (74%) of the patients, respectively. Two (7%) patients had ferritin levels less than 50 ng/mL, and 7 (26%) patients had ferritin levels greater than 50 ng/mL. Fourteen (52%) patients were taking concurrent antidepressants and 6 (22%) were taking sedating antihistamines. Alcohol and tobacco use was documented in 2 (7%) and 8 (30%) patients, respectively. Twenty-six (96%) of the prescribing physicians were primary care providers.

CONCLUSIONS

The findings of this study confirm the need for provider education about the appropriate use of levodopa and dopamine agonists in patients with RLS. Appropriate use of these drugs may help decrease unnecessary adverse effects, complications, and costs.

Genetic association studies of neurotensin gene and restless legs syndrome in French Canadians

BACKGROUND AND PURPOSE

The neurotensin gene (NTS), a known dopamine modulator, is located within the candidate region for the first genetic locus of restless legs syndrome (RLS1) on chromosome 12q. Though no causative mutation was found in selected patients in a previous mutation analysis, the involvement of NTS in RLS cannot be completely excluded as a potential positional and functional candidate gene. The purpose of the current study is to further explore the NTS gene for potential functional variant(s) in its entire genomic and potential regulatory regions and their possible association with RLS symptoms.

METHODS AND SUBJECTS

We resequenced the coding regions and sequenced all the intronic and potential regulatory regions of the NTS gene in additional patients and controls. We carried out full scale gene-based case-control and family-based genetic association studies using the sequence variants detected during mutational analysis.

RESULTS

No coding or variants in regulatory and intronic regions compatible with a deleterious mutation were detected. Seven polymorphisms with elevated allele frequencies in the Caucasian population did not show association with RLS in two independent case-control groups and 110 RLS families.

CONCLUSION

The NTS gene on chromosome 12q is most unlikely to play a direct role in RLS etiology.

Definition of restless legs syndrome, how to diagnose it, and how to differentiate it from RLS mimics

Restless legs syndrome (RLS) is a clinical diagnosis based primarily on self-reports of individuals. The International RLS Study Group has published diagnostic criteria that are essential for an operational diagnosis of RLS; further clinical features are considered by the group supportive for or associated with RLS. However, sensitivity and specificity are not perfect and "mimics" of RLS have been reported, i.e., other conditions like nocturnal cramps sometimes can appear to fulfill the essential diagnostic criteria indicating the need for more thorough understanding of the diagnostic criteria and better differential diagnoses. To contribute to the accuracy of diagnostic processes in RLS, we recapitulate the definition of RLS as an urge to move focused on the legs (and arms in some patients). This urge to move often but not always occurs together with dysesthesia, i.e. unpleasant abnormal sensations appearing without any apparent sensory stimulation. The urge to move and any accompanying dysesthesia must be engendered by rest, relieved by movement and worse in the evening or night. Succinctly, RLS can be summarized in medical terminology as a "movement-responsive quiescegenic nocturnal focal akathisia usually with dysesthesias." Empirical approaches to investigate the independence of the essential criteria "worsening at night" and "worsening at rest" are reported. Possible differential diagnoses of RLS are discussed under the perspective of the NIH diagnostic criteria of RLS. Standardized methods to assess a RLS diagnosis are presented which might improve differential diagnosis and in general the reliability and validity of RLS diagnosis.

Low RLS prevalence and awareness in central Greece: an epidemiological survey

Restless legs syndrome (RLS) is a sensorimotor disorder with a general population prevalence of 3-10%. A single, previous epidemiological study performed in south-east Europe reported the lowest prevalence rate amongst European countries. We conducted a population-based survey of RLS in central Greece. A total of 4200 subjects were randomly recruited. We used the international RLS study group criteria for diagnosis and the severity scale for severity assessment in subjects with RLS. We also included questions to assess the level of awareness of RLS in our region. A total of 3033 subjects were screened. The overall lifetime prevalence was 3.9% with a female-to-male ratio of 2.6:1. Nearly half of RLS patients reported moderate to severe intensity of symptoms. After adjustment for multiple comparisons we found no association of RLS with education level, smoking, alcohol intake, caffeine consumption, shift work, professional pesticide use or comorbid illness. Our study revealed a low level of awareness amongst the population and physicians in our region and sub-optimal management. We provide further evidence for low prevalence of RLS in south-east Europe and a low level of awareness of RLS in our region.

Restless legs syndrome, insomnia, and quality of life after renal transplantation

OBJECTIVE

Restless legs syndrome (RLS) is associated with insomnia and impaired quality of life (QoL) in patients on maintenance dialysis; however, no information has been published on the association of RLS and QoL in kidney-transplanted patients. In a cross-sectional study, we analyzed the complex relationship between RLS, insomnia, and health-related QoL in kidney-transplanted patients.

METHODS

In a cross-sectional survey at a single transplant center, 1067 patients were invited to participate. Complete data set was available from 785 kidney-transplanted patients. The RLS Questionnaire and the Athens Insomnia Scale were used to assess the prevalence of RLS and insomnia, respectively. QoL was measured using the Kidney Disease QoL-SF Questionnaire.

RESULTS

Patients with RLS were three times more likely to have insomnia than patients without RLS (29% vs. 9%, P=.001), and the presence of RLS was a significant and independent predictor of insomnia in multivariate analysis. The presence of RLS was independently associated with impaired health-related QoL along several QoL domains after statistical adjustment for clinical and sociodemographic covariables. Importantly, this association remained significant even after adjusting for insomnia for some QoL domains.

CONCLUSION

RLS is associated with poor sleep, increased odds for insomnia, and impaired QoL in kidney-transplanted patients. Our results suggest that both sleep-related and sleep-independent factors may contribute to the association of RLS and QoL.

Perceived severity of restless legs syndrome across the female life cycle

BACKGROUND

As with migraine, female sex hormones may explain the high prevalence of restless legs syndrome (RLS) in women and therefore influence RLS severity across the female life cycle.

OBJECTIVE AND METHODS

To test this hypothesis, we performed a questionnaire-based transversal survey in female members of the French Association of patients with RLS. Five hundred thirty-six women fulfilled the RLS criteria and completed the International RLS Severity Scale (IRLSSS) and questionnaire about reproductive behaviour, RLS history and perception of RLS symptom severity during pregnancy, menses and menopause.

RESULTS

Patients with at least one child showed a significantly higher mean IRLSSS score than women without children and 23% of the patients declared having perceived worsening of symptoms during pregnancy. Perceived RLS severity was increased during menses in 29% of non-menopaused patients and 69% of the patients reported worsening of symptoms following menopause. In these patients, a tendency towards higher IRLSSS scores was noted. Regression analysis revealed a correlation between higher IRLSSS scores and an early age at onset of RLS.

CONCLUSIONS

Female hormonal changes do not account for the variation in perceived severity in women with RLS during their hormonal milestones and their role in the pathophysiology of RLS is unlikely.

Clinical presentation, diagnosis, and quality of life issues in restless legs syndrome

Restless legs syndrome (RLS) is a generally underdiagnosed and undertreated condition. It is a common cause of sleep disturbance that can severely disrupt normal life functioning. However, because of the failure to recognize RLS as a distinct disorder, clinicians have minimized the significance of the morbidity experienced by some patients. A positive family history is present in >50% of patients with RLS. Indeed, a person with RLS is 3 to 6 times more likely to have a positive family history of RLS than is an individual who does not have the disease. The differential diagnosis of RLS includes both movement and sleep disorders. Establishing an accurate diagnosis is crucial because effective treatment is available. In 2002, RLS experts revised diagnostic criteria and established 4 essential criteria for the diagnosis. Assessing the most bothersome symptoms and quantifying the severity of RLS are important because not all patients require medical therapy. Moreover, therapy may vary according to which symptom represents the major problem.

Epidemiology of restless legs syndrome: the current status

Epidemiological studies in restless legs syndrome (RLS) have often been limited by misdiagnosis and by the fact that affected individuals, even when their symptoms are severe, might not seek medical care. Some of these limitations have been overcome in the last years as population studies based on face to face interviews have been carried out with new standardized diagnostic criteria. According to these studies, and in contrast to earlier views, RLS has been shown to be a common disorder with prevalences ranging between 2.5 and 10% of the population. Although few studies performed outside Europe/North America have shown a low prevalence, a number of methodological issues have been raised that might question these results. Furthermore, once established, RLS usually follows a chronic course, and preliminary evidence shows that it might worsen over time in some patients. Endstage renal disease, increasing age, female gender, pregnancy, frequent blood donations, iron deficiency and neuropathy are considered to be risk factors for this disorder. The association to RLS is less definitely established for other conditions, such as PD or diabetes. In summary, epidemiological evidence suggests that RLS is a common neurological disorder-with high impact on many aspects of the life of those affected.

Gender differences in sleep disorders

PURPOSE OF REVIEW

To evaluate recent evidence regarding gender differences in sleep.

RECENT FINDINGS

Women have better sleep quality compared with men, with longer sleep times, shorter sleep-onset latency and higher sleep efficiency. Despite this, women have more sleep-related complaints than men. The amount of slow-wave sleep decreases with age in men and women. Normal physiologic periods, including puberty, menstruation, pregnancy, and menopause, are associated with alterations in sleep patterns. Gender differences in normal sleep may underlie the observed differences in risk of sleep disorders. Studies of insomnia support a female predominance, with increased divergence of prevalence between men and women with older age. Recent findings for the gender differences in obstructive sleep apnea have focused on differences in local neuromuscular reflexes and central ventilatory control. Restless legs syndrome has a slight female predominance, whereas rapid eye movement sleep behavior disorder and Kleine-Levin syndrome are more common in men.

SUMMARY

Gender differences in sleep become apparent after the onset of puberty. Menstrual cycles, pregnancy, and menopause can alter sleep architecture. Gender-related differences in sleep disorders, such as obstructive sleep apnea, insomnia, and restless legs syndrome, include differences in prevalence, pathophysiology, clinical presentation, and response to therapy.

Prevalence and correlates of restless legs syndrome symptoms in the Wisconsin Sleep Cohort

BACKGROUND AND PURPOSE

The aim of this study was to estimate the prevalence of restless legs syndrome (RLS) symptoms in the US adult population and to relate frequency of RLS symptoms to self-reported general health, depressive and anxiety symptoms, daytime sleepiness, and cardiovascular disease.

PATIENTS AND METHODS

Data were obtained from a survey, conducted in 2002, of 2821 participants in the Wisconsin Sleep Cohort, a prospective community-based epidemiology study. Classification of RLS symptoms was based on the following four symptoms at the 2002 survey: 'repeated urge to move your legs' and 'strange and uncomfortable feelings in the legs', 'when sitting or lying down' which occur at least weekly, 'get better when you get up and start walking' and 'disrupt your sleep'.

RESULTS

Prevalence of RLS symptoms occurring at least weekly was 10.6%, with no statistical difference between males (9.9%) and females (11.2%). Individuals with symptoms of RLS occurring at least weekly were older than those without such symptoms (P<0.02). Those with Daily RLS symptoms had statistically more frequent excessive daytime sleepiness, poorer self-reported general health, an elevation in depressive and anxiety symptoms, and an increased prevalence of cardiovascular disease compared to those with no RLS symptoms. All of these associations were stronger in subjects with Daily RLS symptoms than those with RLS symptoms 1-6 times per week.

CONCLUSIONS

RLS symptoms are associated with multiple physical and psychological indices of impaired health. Longitudinal studies are required to determine whether RLS symptoms are causally related to excessive daytime sleepiness, poor general health, elevated depression and anxiety symptoms, and cardiovascular disease.

Reviews: Diagnosis and Management of Sleep Apnea Syndrome and Restless Legs Syndrome in Dialysis Patients

Sleep complaints are very common in patients with end-stage renal disease (ESRD) and contribute to their impaired quality of life. Both obstructive and central sleep apnea syndromes are reported more often in patients on dialysis than in the general population. Impaired daytime functioning, sleepiness, and fatigue, as well as cognitive problems, are well known in patients with sleep apnea. Increasing evidence supports the pathophysiological role of sleep apnea in cardiovascular disorders, which are the leading cause of death in ESRD patients. Uremic factors may be involved in the pathogenesis of sleep apnea in this patient population and optimal dialysis may reduce disease severity. Furthermore, treatment with continuous positive airway pressure may improve quality of life and may help to manage hypertension in these patients. Secondary restless legs syndrome is highly prevalent in patients on maintenance dialysis. The pathophysiology of the disorder may also involve uremia-related factors, iron deficiency, and anemia, but genetic and lifestyle factors might also play a role. The treatment of restless legs syndrome involves various pharmacologic approaches and might be challenging in severe cases. In this article we review the diagnosis and treatment of sleep apnea and restless legs syndrome, with a focus on dialysis patients. We also briefly review current data regarding sleep problems after transplantation, since these studies may indirectly shed light on the possible pathophysiological role of uremia or dialysis in the etiology of sleep disorders. Considering the importance of sleep disorders, more awareness among professionals involved in the care of patients on dialysis is necessary. Appropriate management of sleep disorders could improve the quality of life and possibly even impact upon survival of renal patients.

Chronic Insomnia in Kidney Transplant Recipients

BACKGROUND

Recent studies confirmed that sleep disorders have a significant impact on various aspects of health in patients at different stages of chronic kidney disease. At the same time, there is an almost complete lack of information on the prevalence and correlates of insomnia in kidney transplant recipients.

METHODS

In a cross-sectional study, the Athens Insomnia Scale was used to assess the prevalence of insomnia in a large sample of kidney transplant recipients compared with wait-listed dialysis patients and also a matched group obtained from a nationally representative sample of the Hungarian population.

RESULTS

The prevalence of insomnia was 15% in wait-listed patients, whereas it was only 8% in transplant recipients (P < 0.001), which, in turn, was not different from the prevalence of this sleep problem in the sample of the general population (8%). Prevalences of insomnia in the transplant group were 5%, 7%, and 14% for the groups with glomerular filtration rates (GFRs) greater than 60 mL/min (> 1.00 mL/s), 30 to 60 mL/min (0.50 to 1.00 mL/s), and less than 30 mL/min (< 0.5 mL/s), respectively (P < 0.01). However, estimated GFR was no longer associated significantly with insomnia in the transplant population after statistical adjustment for several covariates. In a multivariate model, insomnia was significantly and independently associated with treatment modality (transplantation versus wait listing), as well as the presence of depression, restless legs syndrome, and high risk for obstructive sleep apnea syndrome, and with self-reported comorbidity.

CONCLUSION

The prevalence of insomnia was substantially less in the transplant group than in wait-listed dialysis patients and similar to that observed in the general population. Because this condition potentially is treatable, attention should be directed to the appropriate diagnosis and management of insomnia in the kidney transplant recipient population.

Antidepressant medication use and restless legs syndrome in patients presenting with insomnia

BACKGROUND AND PURPOSE

Restless legs syndrome (RLS) is a movement disorder that frequently results in significant complaints of insomnia. Based on published case reports, it is commonly believed that RLS can be caused or exacerbated by antidepressant agents, thus complicating the treatment of depressed patients who are already prone to sleep disturbances. However, there are no systematic studies demonstrating an association between the clinical diagnosis of RLS and the use of antidepressant medication.

PATIENTS AND METHODS

Retrospective chart review of 200 consecutive patients presenting for evaluation of sleep initiation insomnia at an accredited freestanding sleep disorders center that is part of an integrated health care system.

RESULTS

Mean age (+/-SD) of patients was 51.1+/-14.8 years; 60% were women. Fifty-six percent carried a diagnosis of depression, 38% were being treated with antidepressant medication at presentation and 45% met clinical diagnostic criteria for RLS. There were no statistical associations, either by chi(2) analysis or odds ratios, between RLS and antidepressant use or use of any specific class of antidepressant. Positive associations with RLS were found for patients receiving treatment for hypothyroidism and those taking estrogens; a significant negative association was found for patients receiving beta adrenergic antagonists.

CONCLUSIONS

Although there are anecdotal reports of antidepressant use causing or exacerbating RLS, systematic study of this issue fails to corroborate an association.

Effects of rest-duration, time-of-day and their interaction on periodic leg movements while awake in restless legs syndrome

BACKGROUND AND PURPOSE

The diagnostic criteria for restless legs syndrome (RLS) indicate that both time-of-day and rest effects induce or aggravate symptoms. Periodic limb movements while awake (PLMW) provide an objective motor sign of RLS that can be measured during an awake suggested immobilization test (SIT). This study uses the SIT at different times of the day and analyzes time-of-day and duration-of-rest effects and their interaction on the PLMW.

PATIENTS AND METHODS

Twenty-eight RLS patients who were not on medications had SIT tests at 10 pm, 8 am and 4 pm on two consecutive days. PLMW for each 20-min period were analyzed for time-of-day and rest effects and their interaction. PLMW increase from the first to last 20-min SIT period assessed the rest-effects.

RESULTS

Significant effects were found for rest, time-of-day and rest-time-of-day interaction. The rest-effect increased most from morning to afternoon while total PLMW increased more from afternoon to night. Males compared to females had significantly more PLMW and a larger rest-effect change with time-of-day.

CONCLUSIONS

Rest and time-of-day effects and their interaction all increase RLS symptoms. PLMW increase with rest may provide a sensitive measure of symptom severity.

Restless legs syndrome in Parkinson's disease patients may improve with subthalamic stimulation

We report on 6 advanced Parkinson's disease (PD) patients who underwent bilateral subthalamic nucleus (STN) deep brain stimulation (DBS) surgery whose restless legs syndrome (RLS) improved postoperatively. Despite a mean 56% decrease in their levodopa equivalents postoperatively, their RLS scores dropped by a mean of 84% (100% in three). Our findings suggest that bilateral STN DBS surgery can improve RLS in patients with advanced PD.

Segregation Analysis of Restless Legs Syndrome: Possible Evidence for a Major Gene in a Family Study Using Blinded Diagnoses

OBJECTIVE

The objective of this study was to ascertain the most likely inheritance pattern of restless legs syndrome (RLS) using segregation analysis.

METHODS

Probands were RLS patients presenting to the Neurology and Sleep clinics of the Johns-Hopkins Bayview medical center with willing first and second degree relatives. Blinded diagnosis was made in those who exhibited the four diagnostic features of RLS. Analysis was performed on RLS as a dichotomous trait and considering age of onset models on 590 phenotyped subjects from 77 pedigrees.

RESULTS

All non-genetic models were rejected considering RLS as a dichotomous trait. A single locus Mendelian dominant model with gender as a covariate had best fit with allele frequency of 0.077 and complete penetrance. RLS frequency in non-carrier subjects was estimated to be 0.14. Two underlying distributions of age of onset, with a possible dichotomy at 26.3 years, were identified. Contrary to the results for RLS as a dichotomous trait, age of onset models did not indicate single major gene inheritance.

CONCLUSION

This segregation analysis suggests that the pattern of segregation is consistent with that of a single major locus, when RLS is treated as a dichotomous trait without considering age of onset. The high rate of phenocopies matches known population frequencies and taken with significant residual familial effects and the lack of evidence for a major gene controlling age of onset, indicates that non-genetic causes of RLS may exist and RLS is a complex disorder.

Management of Restless Legs Syndrome in Patients on Dialysis

Restless legs syndrome (RLS) is characterised by an urge to move the legs, uncomfortable sensations in the legs and worsening of these symptoms during rest with at least temporary relief brought on by activity. RLS occurs in 3-15% of the general population and in 10-30% of patients on maintenance dialysis. RLS may lead to severe sleep onset or maintenance insomnia, and greatly impaired quality of life. Current recommendations suggest dopaminergic therapy (levodopa or dopamine receptor agonists: pramipexol, ropinirole, pergolide or cabergoline) as the first-line treatment for RLS. This group of medications is effective in reducing RLS symptoms in the general population; limited information is available on the effect of these drugs in patients with renal failure. However, it must be noted that most published studies in uraemic patients had short treatment periods and insufficient statistical power because of small sample size. Frequent adverse effects of levodopa, seen mainly with continuous use, may limit its use significantly. Rebound and augmentation, problems relatively frequently seen with levodopa, seem to be less prevalent with the use of dopamine receptor agonists, although properly designed comparative trials are still needed to address this question. Alternative treatment options for RLS are gabapentin, benzodiazepines and opioids. For all of these medications, there are only very limited data available on their effectiveness and safety profile in patients on maintenance dialysis. Referral to a specialist for RLS management should be considered for patients with refractory RLS.

Restless Legs Syndrome

Restless legs syndrome (RLS) is clinically defined as an urge to move the legs with or without paresthesia, worsening of symptoms with rest and transient improvement with activity, and worsening of symptoms in the evening and night. This is often genetic but may also occur in the setting of iron deficiency, uremia, pregnancy, neuropathy, and possibly other conditions. The pathology is probably related to central nervous system iron dysregulation. Effective treatments include dopaminergics and narcotics. Recent advances in our understanding of RLS clinical presentation, epidemiology, etiology, and treatment will be discussed.

The restless legs syndrome

The restless legs syndrome (RLS) is one of the commonest neurological sensorimotor disorders at least in the Western countries and is often associated with periodic limb movements (PLM) during sleep leading to severe insomnia. However, it remains largely underdiagnosed and its underlying pathogenesis is presently unknown. Women are more affected than men and early-onset disease is associated with familial cases. A genetic origin has been suggested but the mode of inheritance is unknown. Secondary causes of RLS may share a common underlying pathophysiology implicating iron deficiency or misuse. The excellent response to dopaminegic drugs points to a central role of dopamine in the pathophysiology of RLS. Iron may also represent a primary factor in the development of RLS, as suggested by recent pathological and brain imaging studies. However, the way dopamine and iron, and probably other compounds, interact to generate the circadian pattern in the occurrence of RLS and PLM symptoms remains unknown. The same is also the case for the level of interaction of the two compounds within the central nervous system (CNS). Recent electrophysiological and animals studies suggest that complex spinal mechanisms are involved in the generation of RLS and PLM symptomatology. Dopamine modulation of spinal reflexes through dopamine D3 receptors was recently highlighted in animal models. The present review suggests that RLS is a complex disorder that may result from a complex dysfunction of interacting neuronal networks at one or several levels of the CNS and involving numerous neurotransmitter systems.

Restless Legs Syndrome

RLS is a common condition that is likely to be encountered by primary care physicians in their practice. The currently available medications are highly effective in treating RLS. The knowledge of clinical presentation and diagnostic features of RLS will empower the primary care practitioners to effectively treat their patients who have RLS.

Prevalence of restless legs syndrome and associated factors in the Korean adult population: the Korean Health and Genome Study

The present study was purposed to identify the prevalence of restless legs syndrome (RLS) and its associated factors in the Korean adult population. Among a total of 9939 participants derived from the Korean Health and Genome Study, 12.1% of subjects (men, 8.5%; women, 15.4%) suffered from RLS. Factors independently related with RLS were older age and frequent fatigue in both men and women.

Analysis of familial and sporadic restless legs syndrome in age of onset, gender, and severity features

Restless Legs Syndrome is characterized by the irresistible, often indescribable unpleasant urge to move the limbs while resting. It has an estimated prevalence of approximately 29.3 % in US private practice. Restless Legs Syndrome often has a familial component; whether the familial and non-familial forms differ in terms of clinical features has previously been investigated, with the only significant factor emerging as younger age at onset in familial cases. Our study further explores a possible underlying difference between familial and sporadic forms of RLS by comparing familial RLS with sporadic RLS in terms of demographic and clinical features including subject gender, age of onset, and severity measures based an the IRLSSG severity scale. Both gender and family history are significant predictors of onset age in an overall model and also significant when analyzed independently. Participants who reported more severe RLS symptoms were significantly younger in age and progressed more rapidly. Two variables from the IRLSSG severity scale were significantly associated with age of onset when tested independently: discomfort and the urge to move the limb for relief. Our analysis supports the prevailing hypothesis that RLS is divided into earlier onset disease with a clear genetic component and later onset disease with unclear etiology, and that one or more endophenotypes might exist within the disorder which could further characterize these subjects for future genetic studies.

Restless legs syndrome in patients after renal transplantation

BACKGROUND

There is an almost complete lack of information on the epidemiology of sleep disorders in kidney-transplanted patients. In this report the authors assess the prevalence and clinical correlates of restless legs syndrome (RLS) in kidney-transplanted (Tx) patients. They also analyze the impact of declining renal function on this condition in the Tx population. Finally, the prevalence of RLS was compared between waitlisted dialysis patients (WL), and the Tx group.

METHODS

In a cross-sectional study enrolling 992 patients (816 Tx and 176 WL), the presence of RLS was assessed using the Restless Legs Syndrome Questionnaire. Clinical and sociodemographic data were collected from the patients' medical records.

RESULTS

In transplanted patients, the prevalence of RLS was 4.8%. RLS was associated strongly with declining renal function. In groups formed on the basis of estimated glomerular filtration rate (eGFR), the prevalence of RLS was 1.8%, 5.1%, 6.5%, and 23.5% in patients with eGFR greater than 60 mL/min/1.73 m 2 ; eGFR 30 to 59 mL/min/1.73 m 2 ; eGFR 15 to 29 mL/min/1.73 m 2 ; and eGFR less than 15 mL/min/1.73 m 2 , respectively (P < 0.001). There was also a significant association between RLS and lower serum hemoglobin, higher number of self-reported comorbid conditions, and higher prevalence of iron deficiency. RLS was significantly less frequent in patients taking steroids than in patients not taking this medication (4% versus 9%, P < 0.05). In multivariate analysis, not taking steroids, eGFR, self-reported comorbidity, and iron deficiency were significant and independent predictors of RLS. Dialysis treatment was associated with increased odds for RLS (odds ratio 2.2; 95% confidence interval 1.11 to 4.35; P < 0.05) even after adjusting for serum hemoglobin and comorbidity.

CONCLUSION

The prevalence of RLS is significantly lower in Tx patients than in patients on maintenance dialysis. Declining renal function is associated with increasing prevalence of the condition.

Restless legs syndrome, insomnia and quality of life in patients on maintenance dialysis

BACKGROUND

In a cross-sectional study, we analysed the complex relationship between restless legs syndrome (RLS), insomnia and specific insomnia symptoms and health-related quality of life (QoL) in patients on maintenance dialysis.

METHODS

Data were obtained from 333 patients on chronic maintenance dialysis. To assess the prevalence of RLS, we used the RLS Questionnaire (RLSQ). The Athens Insomnia Scale (AIS) was used to assess insomnia and QoL was measured with the Kidney Disease Quality-of-Life Questionnaire.

RESULTS

The prevalence of RLS was 14%. The number of comorbid conditions was significantly higher in patients with vs without RLS (median: three vs two; P<0.05). RLS patients were twice as likely to have significant insomnia as patients without RLS (35% vs 16%; P<0.05). Furthermore, RLS was associated with impaired overall sleep quality (median AIS score: 8 vs 4; P<0.01) and poorer QoL. RLS was a significant and independent predictor of several of the QoL domains after statistical adjustment for clinical and socio-demographic covariables. Importantly, this association remained significant even after adjusting for sleep quality.

CONCLUSIONS

RLS is associated with poor sleep, increased odds for insomnia and impaired QoL in patients on maintenance dialysis. Based on the present results, we suggest that both sleep-related and sleep-independent factors may confer the effect of RLS on QoL.

An algorithm for the management of restless legs syndrome

Restless legs syndrome (RLS) is a common disorder with a prevalence of 5% to 15%. Primary care physicians must become familiar with management of this disorder. This algorithm for the management of RLS was written by members of the Medical Advisory Board of the Restless Legs Syndrome Foundation and is based on scientific evidence and expert opinion. Restless legs syndrome is divided into intermittent, daily, and refractory types. Nonpharmacological approaches, including mental alerting activities, avoiding substances or medications that may exacerbate RLS, and addressing the possibility of iron deficiency, are discussed. The role of carbidopa/levodopa, dopamine agonists, opioids, benzodiazepines, and anticonvulsants for the different types of the disorder is delineated.

Síndrome das Pernas Inquietas

A síndrome das pernas inquietas (SPI) é ainda uma condição médica relativamente desconhecida da classe médica. A introdução oficial dos agentes dopaminérgicos como primeira escolha no tratamento proporcionou uma conscientização a respeito da SPI. Apesar disso, o diagnóstico correto e o tratamento podem demorar causando anos de sofrimento. È importante pesquisar e tratar as causas primária da SPI e de comorbidades como depressão e polineuropatia. Tratamento de casos resistentes, efeitos colaterais como a expansão podem ser minimizados a partir do conhecimento dos detalhes de algoritmo do tratamento e seguimento médico.