Recent advances in the diagnosis, genetics and treatment of restless legs syndrome

Stroke-related restless leg syndrome in hemorrhagic and ischemic stroke patients

Objectives

The incidence of stroke-related restless legs syndrome (RLS) has been reported to be high but varies regionally. Therefore, this study aimed to investigate the incidence and some of the factors related to restless legs syndrome after stroke onset in patients in Vietnam.

Methods

Data were collected from a total of 423 patients who had stroke, including 283 ischemic and 140 hemorrhagic strokes, which were confirmed by magnetic resonance imaging within 7 days after the onset of symptoms, at the Department of Stroke, Military Hospital 103 from September 2023 to April 2024. Restless legs syndrome was diagnosed 1 month after the stroke onset according to the criteria of the International Restless Legs Syndrome Study Group.

Results

Restless legs syndrome was diagnosed in 59 patients (11.6%), including 37 (13.1%) who had ischemic stroke and 12 (8.6%) who had hemorrhagic stroke. An increased rate of restless legs syndrome was observed in stroke patients with brain lesions in the thalamus and lentiform nucleus; those who smoked; and those with a family history of restless legs syndrome.

Conclusions

This study found that the incidence of restless legs syndrome after stroke was 11.6% overall and 13.1% and 8.6% after ischemic and hemorrhagic strokes, respectively. Lesion in the thalamus and lentiform nucleus, smoking history, and family history of restless legs syndrome were the predictors of restless legs syndrome after stroke onset.

Association between Self-Perceived Periodic Limb Movement during Sleep and Excessive Daytime Sleepiness Depend on Restless Leg Symptoms in Korean Adolescents

Although periodic limb movement during sleep (PLMS) and restless legs syndrome (RLS) are common in children and adolescents, they are relatively overlooked as a target of treatment. PLMS has been evaluated as having a lower clinical significance than RLS. This study examined the relationship of socio-behavioral factors of PLMS in Korean adolescents and checked whether PLMS is associated with excessive daytime sleepiness (EDS), depending on whether restless legs symptoms accompany it. In a cross-sectional study, 25,789 adolescents between 12 and 18 years of age (15.76 ± 1.73 years; female 51.49%) were evaluated using an online survey. Various self-report questionnaires were used to assess PLMS and RLS symptoms, EDS, sleep habits, and various socio-behavioral factors. The prevalence of self-perceived PLMS and restless legs symptoms were 903 (3.50%) and 1311 (5.08%), respectively. Of the 1311 participants, 399 had self-perceived PLMS. The odds ratios (ORs) for self-perceived PLMS in participants with restless legs symptoms were: males (OR = 1.528; 95% CI: 1.145–2.040), usually/always experienced apnea apnea (OR, 3.006; 95% CI, 1.954–4.624), increased proneness to Internet addiction (OR = 1.013; 95% CI: 1.001–1.025), sometimes/often consuming coffee (OR = 1.312; 95% CI: 1.015–1.695), EDS (OR = 0.826; 95% CI: 0.488–1.398), and perceived insufficient sleep (OR = 1.143; 95% CI: 0.835–1.565). The male gender, witness apnea, consuming coffee, and being prone to Internet addiction were identified as factors significantly associated with self-perceived PLMS in participants with restless legs symptoms. However, EDS and insufficient sleep were associated with self-perceived PLMS in the absence of restless legs symptoms.

Management of Restless Legs Syndrome in Pregnancy and Lactation

Restless legs syndrome (RLS) affects about 20% of all pregnant women. RLS symptoms are usually moderate to severe in intensity during pregnancy and can result in insomnia, depression, and other adverse outcomes. Although iron deficiency has been implicated as a potential etiological factor, other mechanisms can also play a role. Nonpharmacologic methods are the primary recommended form of treatment for RLS in pregnancy and lactation. Iron supplementation may be considered when the serum ferritin is low; however, several patients are unable to tolerate iron or have severe symptoms despite oral iron replacement. Here, we describe a case of severe RLS in pregnancy and illustrate the dilemmas in diagnosis and management. We review the literature on the prevalence, diagnosis, course, possible underlying pathophysiologic mechanisms and complications of RLS in pregnancy. We describe current best evidence on the efficacy, and safety of nonpharmacologic therapies, oral and intravenous iron supplementation, as well as other medication treatments for RLS in pregnancy and lactation. We highlight gaps in the literature and provide a practical guide for the clinical management of RLS in pregnancy and during breastfeeding.

Evaluation of upper endoscopic findings in patients with restless legs syndrome and gastric complaints

BACKGROUND

The effect of gastrointestinal system disorders on Restless Legs Syndrome/Willis-Ekbom disease (RLS/WED) has been previously demonstrated by using serological tests. However, this association has not been supported by histopathological studies so far.

OBJECTIVE

To investigate the relationship between RLS/WED, upper endoscopic imaging and histopathological results in patients diagnosed with RLS who underwent endoscopy because of gastrointestinal system (GIS) complaints.

METHODS

Case-control study, including 100 patients diagnosed with RLS who presented dyspeptic complaints and underwent upper GIS endoscopy and 106 age- and sex-matched controls. RLS diagnosis was evaluated according to the four main diagnostic criteria determined by the International RLS Study Group. All patients underwent upper GIS endoscopic intervention and at least one gastric and/or antral biopsy.

RESULTS

There was no significant difference between patients and controls in relation to endoscopically seen gastric ulcer, duodenal ulcer, gastroesophageal reflux disease (GERD) findings and Helicobacter pylori (HP) positivity (p>0.05). Intestinal metaplasia and mucosal atrophy were more common in RLS/WED patients compared to controls (p=0.026 and p=0.017, respectively). Additionally, ferritin levels were found to be lower than the reference value.

CONCLUSIONS

The detection of increased severity of intestinal metaplasia, mucosal atrophy, and gastric inflammation in RLS/WED patients with dyspeptic complaints may entail the close gastrointestinal system evaluation of these patients. However, larger randomized and controlled trials are required on this subject where patients are evaluated by upper GIS endoscopic biopsy.

Evaluation of restless leg syndrome symptoms in patients with lumbosacral canal stenosis comparison with normal population

Introduction: Restless leg syndrome (RLS) is a neurological disorder that causes an irresistible urge to move the legs often associated with an unpleasant sensation. Due to some common presentations between RLS and lumbosacral spinal stenosis, the purpose of this study was to evaluate the symptoms of RLS in the presence of spinal stenosis at the same time as normal populations.Materials and methods: This cross-sectional study examined 45 patients with lumbosacral spinal canal stenosis and 45 normal individuals without a specific disease. Patients aged 50-70 years were included in the study. All the statistical analyses were carried out using SPSS 21.0 software and p < 0.05 was considered statistically significant.Results: 19 subjects (42.22%) in the patient group and eight in the normal group (17.8%) suffered from restless leg syndrome. Multiple linear regression analysis revealed that patients with lumbosacral canal stenosis had almost five score less than others in RLS scale.Conclusion: RLS symptoms were more prominent in lumbosacral canal stenosis patients compared to the normal group. The awareness of its symptoms can help reduce misdiagnosis.

High-Resolution Nerve Ultrasound and Electrophysiological Findings in Restless Legs Syndrome

BACKGROUND AND PURPOSE

Restless legs syndrome (RLS) is a multifactorial network disorder of a sensorimotor system extending from dopaminergic and glutamatergic cerebral structures to the spinal neurons and peripheral nerves. The role of peripheral nerve damage in the causality and severity progression for RLS patients remains unclear.

METHODS

We performed a clinical and epidemiological study on a cohort of 34 RLS patients focusing on RLS risk factors and disease severity. We investigated the peripheral nerves with nerve conduction studies and with high-resolution nerve ultrasound (HRUS).

RESULTS

In 18 of the 34 patients (mean age 67.4 ± 15 years old), a sensorimotor axonal neuropathy was diagnosed. These patients presented with late-onset RLS were treated with membrane stabilizing agents, whereas no neuropathy predisposing comorbidity could be identified for the majority of them. We could show an inverse correlation between the amplitudes of the tibial nerve for the patients with polyneuropathy and the RLS severity index. Neuropathy patients were characterized by an increase of the cross-sectional area (CSA) of the tibial nerve in the popliteal fossa and by increased intranerve and internerve variability values showing an asymmetry of CSA distribution. This pattern resembles previous studies on diabetic neuropathy.

CONCLUSIONS

Early diagnosis, characterization, and treatment of neuropathy are increasingly relevant for RLS patients as it correlates with disease severity. HRUS revealed a pattern resembling diabetic neuropathy, which implies a similar pathophysiology with metabolic and ischemic origin of RLS-related axonal neuropathy.

[Genetic risk variants in Parkinson's disease and other movement disorders]

Movement disorders are often genetically complex with genetic risk factors playing a major role. For example, monogenic causes of Parkinson's disease (PD) can be found in only 2-5% of patients who often have an early onset (<40 years). In the majority of patients, common genetic variants seem to contribute to the disease risk. To date, 24 genetic risk factors have been identified. For restless legs syndrome (RLS), six different risk variants have been reported but no monogenic cause is known yet. For the genetic risk factors of essential tremor and dystonia, which are less well studied, only five and two candidate variants, respectively, have been described but their roles still require independent confirmation. In this review, we provide an overview on the involved genes, their function, and discuss possible, disease mechanism-driven therapies.

Brain imaging and networks in restless legs syndrome

Several studies provide information useful to our understanding of restless legs syndrome (RLS), using various imaging techniques to investigate different aspects putatively involved in the pathophysiology of RLS, although there are discrepancies between these findings. The majority of magnetic resonance imaging (MRI) studies using iron-sensitive sequences supports the presence of a diffuse, but regionally variable low brain-iron content, mainly at the level of the substantia nigra, but there is increasing evidence of reduced iron levels in the thalamus. Positron emission tomography (PET) and single positron emission computed tomography (SPECT) findings mainly support dysfunction of dopaminergic pathways involving not only the nigrostriatal but also mesolimbic pathways. None or variable brain structural or microstructural abnormalities have been reported in RLS patients; reports are slightly more consistent concerning levels of white matter. Most of the reported changes were in regions belonging to sensorimotor and limbic/nociceptive networks. Functional MRI studies have demonstrated activation or connectivity changes in the same networks. The thalamus, which includes different sensorimotor and limbic/nociceptive networks, appears to have lower iron content, metabolic abnormalities, dopaminergic dysfunction, and changes in activation and functional connectivity. Summarizing these findings, the primary change could be the reduction of brain iron content, which leads to dysfunction of mesolimbic and nigrostriatal dopaminergic pathways, and in turn to a dysregulation of limbic and sensorimotor networks. Future studies in RLS should evaluate the actual causal relationship among these findings, better investigate the role of neurotransmitters other than dopamine, focus on brain networks by connectivity analysis, and test the reversibility of the different imaging findings following therapy.

Relationships Between Malnutrition, Inflammation, Sleep Quality, and Restless Legs Syndrome in Hemodialysis Patients

Restless legs syndrome (RLS) is a common neurologic sensorimotor disorder. It is also seen in hemodialysis patients in whom the mechanism is not thoroughly understood. The aim of this study was to evaluate the association between malnutrition-inflammation score (MIS), sleep quality, and RLS in chronic hemodialysis patients. This cross-sectional study included 232 adult stable chronic hemodialysis patients (mean age 60.9 ± 14.1 years, 56.5% male). RLS frequency, MIS, Pittsburgh Sleep Quality Index (PSQI), laboratory data of patients as well as severity of RLS were evaluated. Thirty-seven patients (15.9%) were diagnosed with RLS. Mean MIS of patients with or without RLS were similar. PSQI of patients with RLS was significantly higher than patients without RLS (P = 0.002). There was a significant positive correlation between RLS severity and PSQI (r = 0.445, P = 0.006). A significant positive correlation was also found between PSQI and MIS in patients with RLS (r = 0.419, P = 0.010). RLS severity was positively correlated with some inflammatory parameters such as white blood cell count and C-reactive protein (r = 0.427, P = 0.008 and r = 0.418 P = 0.010). PSQI was found as an independent significant predictor of RLS (odds ratio [OR] = 1.15 (1.06-1.25), P = 0.001) in multivariate logistic regression analysis. Our study revealed that there was no significant relationship between RLS and MIS in chronic hemodialysis patients. However, RLS severity is correlated with inflammatory parameters. Also, sleep quality in chronic hemodialysis patients with RLS is negatively associated with MIS.

Transcranial magnetic stimulation for evaluation of motor cortical excitability in restless legs syndrome/Willis-Ekbom disease

There is no consensus about mechanisms underlying restless legs syndrome (RLS), also known as Willis-Ekbom disease (WED). Cortical excitability may be abnormal in RLS. Transcranial magnetic stimulation (TMS) can provide insight about cortical excitability. We reviewed studies about measures of excitability to TMS in RLS. Original studies published between January 1999 and January 2015 were searched in PubMed, Scopus, and Web of Science databases. Inclusion criteria were as follows: original studies involving primary RLS in patients from both sexes and ages between 18 and 85 years; TMS protocols clearly described; and they were written in English, in peer-reviewed journals. Fifteen manuscripts were identified. TMS protocols were heterogeneous across studies. Resting motor threshold, active motor threshold, and amplitudes of motor-evoked potentials were typically reported to be normal in RLS. A reduction in short-interval intracortical inhibition (SICI) was the most consistent finding, whereas conflicting results were described in regard to short-interval intracortical facilitation and the contralateral silent period. Decreased SICI can be reversed by treatment with dopaminergic agonists. Plasticity in the motor cortex and sensorimotor integration may be disrupted. TMS may become a useful biomarker of responsiveness to drug treatment in RLS. The field can benefit from increases in homogeneity and sizes of samples, as well as from decrease in methodological variability across studies.

Restless legs syndrome as a first manifestation of a cerebral infarct

The onset of restless legs syndrome (RLS) is usually progressive and the neural substrates underlying its pathophysiology remain to be identified. Here we report on a patient presenting with acute-onset RLS that was symptomatic of a right anteromedial pontine infarction. This case is exceptional because RLS appeared several hours before the occurrence of a regressive dysarthria clumsy-hand syndrome. Additionally, millimetric MRI sections showed that the structures possibly involved in RLS pathogenesis were the corticospinal tract, the pontine nuclei, and the pontocerebellar fibers. Although this is uncommon, clinicians should be aware that RLS characterized by a sudden onset can be a clinical manifestation related to stroke.

Restless legs syndrome status as a predictor for lower physical function

OBJECTIVE

To examine the potential long-term impact of restless legs syndrome (RLS) and other common sleep complaints on subsequent physical function (PF), we conducted a longitudinal analysis of 12,556 men in the Health Professionals Follow-up Study.

METHODS

We used a set of questions recommended by the International RLS Study Group to assess RLS in 2002. We asked questions regarding other sleep complaints--insomnia, sleep fragmentation, and excessive daytime sleepiness--in 2004. We used the Physical Function (PF-10) survey of the Short Form-36 Health Survey to characterize PF in 1996 and 2008. We examined the 2008 PF-10 scores across categories of baseline RLS (2002), adjusted for age, 1996 PF-10 score, and other potential confounders.

RESULTS

The participants with RLS at baseline had significantly lower PF-10 score 6 years later than those without RLS (mean difference = -2.32, p = 0.01), after adjusting for potential confounders. The magnitude of difference in PF-10 score for RLS symptoms ≥ 15 times/month vs no RLS was more than that of a 5-year increase of age or moderate amount of smoking. Having daily daytime sleepiness and sleep duration ≥ 9 hours/day were associated with lower mean PF value than not having these symptoms (p < 0.05 for both).

CONCLUSIONS

RLS and other sleep complaints are associated with lower PF. Our findings need to be replicated by more longitudinal studies including women and populations of other social and cultural backgrounds. It is important to understand whether RLS is an independent risk factor or a marker for other unknown risk factors for disability.

Restless legs syndrome associated with exercise intolerance: Data from a retrospective observational clinical neuromuscular center study

INTRODUCTION

Exercise intolerance (EI) is a frequent motive for seeking neuromuscular consultation and may be a sign of metabolic disease or, rarely, muscular dystrophy. The diagnosis is not established in many patients with a typical clinical presentation. Nevertheless, some of them complain of sleep disorders and more especially of restless legs syndrome (RLS).

OBJECTIVE

The objective of our study was to estimate the frequency of RLS in patients presenting with EI.

METHODS

Our retrospective observational study included all patients seen in the center from 2005 to 2011, who were subsequently investigated for EI in the neuromuscular department of the Caen University hospital. Data were collected on clinical RLS and muscular investigations (creatine kinase [CK], EMG, maximal exercise tests magnetic resonance imaging [MRI] and muscle biopsy obtained along with muscle exploration).

RESULTS

Of the 318 patient records analyzed, 84 showed patients accurately complaining of EI. RLS was diagnosed in 25 of these patients (29.7%). This percentage was significantly higher (P<0.001) than found in the general population. Improvement was seen in 91.3% of the patients receiving specific treatment.

CONCLUSION

RLS can sometimes present with pain, potentially worsening with exercise, inappropriately leading to a hypothesis of EI. Clinicians should thus explore the possible diagnosis of RLS when a muscular disease is not found in patients presenting with such symptoms.

Restless legs syndrome: impact on sleep-related breathing disorders

Restless legs syndrome (RLS) is a common chronic sensory-motor neurological disorder that remains a clinical diagnosis. Most RLS patients present with sleep complaints in the form of initiation and/or maintenance insomnia as RLS has a circadian rhythmicity. An increased number of periodic leg movements during sleep (PLMS) is a supportive criterion in the diagnosis of RLS. Abnormalities in the central dopaminergic and iron systems are involved in the physiopathology of RLS. There is a higher prevalence of RLS and PLMS in sleep-disordered breathing patients, particularly those with obstructive sleep apnoea (OSA), the most common sleep disorder in western societies. The complex mechanisms underlying the association between OSA, RLS and PLMS remain unclear. Untreated OSA can lead to adverse cardiovascular consequences due to cardio-metabolic dysfunction. It remains controversial whether RLS could further adversely impact the cardiovascular consequences of OSA. The PLMS do not have an additive effect on the hypersomnia experienced by some sleep-disordered breathing patients. Continuous positive airway pressure (CPAP) therapy is the most effective therapy for OSA. The presence of PLMS during CPAP treatment could be a marker of an incomplete resolution of sleep-disordered breathing in the form of increased upper airway resistance syndrome, despite treatment. Dopaminergic agonists are the preferred agent for the treatment of RLS, and are indicated when RLS symptoms are frequent and affect quality of life. PLMS and RLS do not seem to contribute to the residual hypersomnia that can be observed in some sleep-disordered breathing patients despite adequate compliance and effective CPAP therapy.

Sleep-related movement disorders

PURPOSE OF REVIEW

This article reviews the sleep-related movement disorders, including restless legs syndrome (RLS; Willis-Ekbom disease), periodic limb movement disorder, rhythmic movement disorders, sleep-related bruxism, and sleep-related leg cramps.

RECENT FINDINGS

The prevalence of clinically significant RLS is 1.5% to 3.0%. The pathophysiology of RLS may involve abnormal iron transport across the blood-brain barrier and down-regulation of putaminal D2 receptors. The availability of the rotigotine patch provides an additional form of dopaminergic therapy for RLS. Calcium channel alpha-2-delta ligands (gabapentin, gabapentin enacarbil, and pregabalin) provide alternative therapies for RLS especially in patients with augmentation, impulse control disorders, or hypersomnia induced by dopamine agonists. Long-term use of opioid medication is safe and effective for refractory cases of RLS.

SUMMARY

RLS is a common disorder causing considerable morbidity. Accurate diagnosis and appropriate investigations are essential. Many effective therapies are available, but the side effects of each class of medication should be considered in determining optimal treatment. Periodic limb movements of sleep, bruxism, and rhythmic movement disorders are sleep-related phenomena often accompanying other sleep disorders and only sometimes requiring primary therapy. Sleep-related leg cramps are generally idiopathic. Management is challenging with few effective therapies.

Protein tyrosine phosphatase variants in human hereditary disorders and disease susceptibilities

Reversible tyrosine phosphorylation of proteins is a key regulatory mechanism to steer normal development and physiological functioning of multicellular organisms. Phosphotyrosine dephosphorylation is exerted by members of the super-family of protein tyrosine phosphatase (PTP) enzymes and many play such essential roles that a wide variety of hereditary disorders and disease susceptibilities in man are caused by PTP alleles. More than two decades of PTP research has resulted in a collection of PTP genetic variants with corresponding consequences at the molecular, cellular and physiological level. Here we present a comprehensive overview of these PTP gene variants that have been linked to disease states in man. Although the findings have direct bearing for disease diagnostics and for research on disease etiology, more work is necessary to translate this into therapies that alleviate the burden of these hereditary disorders and disease susceptibilities in man.

Restless legs syndrome: pathophysiology and modern management

Restless legs syndrome (RLS) is a common sensory motor neurological disorder that is characterised by an irresistible urge to move the legs that significantly affects the quality of life of the patient. Prevalence in the general population is 5-25% and it is twice as prevalent in women as in men. RLS is the most common movement disorder in pregnancy with a fourfold increased risk of developing this disorder later in life. The pathophysiology of RLS is centred on dopaminergic dysfunction, reduced central nervous system iron, genetic linkages, or alteration in neurotransmitters such as hypocretins, endorphins levels and immune dysfunction and inflammatory mechanisms. With the emergence of new evidence, there are changes to the previous treatment recommendations for RLS. There is sufficient evidence to conclude that dopamine agonists such as rotigotine transdermal patch, pramipexole, ropinirole, gabapentin enacarbil, pregabalin and gabapentin are effective in the short-term treatment of RLS and rotigotine, followed by gabapentin enacarbil, ropinirole, pramipexole and gabapentin for long-term treatment. Based on expert consensus, the recommendation for daily RLS is dopamine agonists or gabapentin or low-potency opioids. Levodopa is less preferred for treating daily RLS due to its high risk of augmentation. For intermittent RLS, it is levodopa or dopamine agonists or low-potency opioids or benzodiazepines. For refractory RLS, the choice is to change to gabapentin or a different dopamine agonist, addition of a second agent like gabapentin or benzodiazepine to the existing drug or changing to a high-potency opioid or tramadol. Medications with safety record in pregnancy include opioids and antiepileptics such as carbamazepine and gabapentin. There are concerns that patients with RLS are at risk for metabolic deregulation, autonomic dysfunction and cardiovascular morbidity. However, a recent study concluded that RLS is not associated with increased risk of cardiovascular complications.

Association between sleep disorders, obesity, and exercise: a review

Decreased sleep duration and quality is associated with an increase in body weight and adiposity. Insomnia, obstructive sleep apnea, and restless legs syndrome are three of the most prevalent types of sleep disorder that lead to an increased risk for numerous chronic health conditions. Various studies have examined the impact of these sleep disorders on obesity, and are an important link in understanding the relationship between sleep disorders and chronic disease. Physical activity and exercise are important prognostic tools in obesity and chronic disease, and numerous studies have explored the relationship between obesity, sleep disorders, and exercise. As such, this review will examine the relationship between sleep disorders and obesity. In addition, how sleep disorders may impact the exercise response and how exercise may impact patient outcomes with regard to sleep disorders will also be reviewed.

Recurrent CSPs after Transcranial Magnetic Stimulation of Motor Cortex in Restless Legs Syndrome

Aims. The aim of this study was to investigate the motor control and central silent period (CSP) in restless legs syndrome (RLS). Methods. Transcranial magnetic stimulation was focused on the dominant and nondominant hemispheric areas of motor cortex in six subjects with RLS and six controls. The responses were recorded on the contralateral abductor digiti minimi (ADM) and tibialis anterior (TA) muscles with intramuscular needle electrodes. Results. No significant differences were found in the motor conduction or central motor conduction time, in the latency, or in the duration of the CSPs between or within the groups, but multiple CSPs were observed in both groups. The number of the CSPs was significantly higher in both ADMs and in the dominant TA (P ≤ 0.01) in the RLS group compared to the controls. Conclusion. Descending motor pathways functioned correctly in both groups. The occurrence of the recurrent CSPs predominantly in the RLS group could be a sign of a change of function in the inhibitory control system. Further research is needed to clarify the role of the intramuscular recording technique and especially the role of the subcortical generators in the feedback regulation of the central nervous system in RLS.

The psychopharmacological management of RLS in psychiatric conditions: a review of the literature

BACKGROUND

Restless legs syndrome (RLS) is a movement disorder treated with dopamine agonists. RLS is often diagnosed as a comorbid condition with psychiatric disorders, which are treated with dopamine antagonists or antidepressants resulting in onset or exacerbation of RLS symptoms.

OBJECTIVES

The objectives of this article are to provide a review of the literature to (a) describe the comorbidity of psychiatric disorders associated with RLS, (b) identify the treatment of psychiatric disorders that cause or exacerbate symptoms of RLS, and (c) provide clinical recommendations for psychiatric health care providers.

DESIGN

A review of the literature of English articles included the databases of Medline, Pubmed, PsychINFO, and CINAHL for "Restless Legs Syndrome" with major psychiatric disorders including mood disorders (depression and bipolar), schizophrenia, and anxiety disorders (anxiety, panic disorder, obsessive compulsive disorder). The PRISMA guidelines were used to improve the reporting of the review of the literature.

RESULTS

There were 61 articles that met the inclusion and exclusion criteria identified for the review of the literature, including RLS with mood disorders (n = 36), schizophrenia (n = 9), and anxiety disorders (n = 16).

CONCLUSIONS

Clinical trials are lacking on the best treatment for persons with RLS and psychiatric disorders; the most rigorous research found in the literature related to depression and anxiety. Studies lack evidence to document the best practice for persons with RLS and comorbid psychiatric disorders. Psychiatric health care providers should be aware of RLS, which is influenced by psychiatric medications.

Genome-wide association study of motor coordination problems in ADHD identifies genes for brain and muscle function

OBJECTIVES

Motor coordination problems are frequent in children with attention deficit/hyperactivity disorder (ADHD). We performed a genome-wide association study to identify genes contributing to motor coordination problems, hypothesizing that the presence of such problems in children with ADHD may identify a sample of reduced genetic heterogeneity.

METHODS

Children with ADHD from the International Multicentre ADHD Genetic (IMAGE) study were evaluated with the Parental Account of Children's Symptoms. Genetic association testing was performed in PLINK on 890 probands with genome-wide genotyping data. Bioinformatics enrichment-analysis was performed on highly ranked findings. Further characterization of the findings was conducted in 313 Dutch IMAGE children using the Developmental Coordination Disorder Questionnaire (DCD-Q).

RESULTS

Although none of the findings reached genome-wide significance, bioinformatics analysis of the top-ranked findings revealed enrichment of genes for motor neuropathy and amyotrophic lateral sclerosis. Genes involved in neurite outgrowth and muscle function were also enriched. Among the highest ranked genes were MAP2K5, involved in restless legs syndrome, and CHD6, causing motor coordination problems in mice. Further characterization of these findings using DCD-Q subscales found nominal association for 15 SNPs.

CONCLUSIONS

Our findings provide clues about the aetiology of motor coordination problems, but replication studies in independent samples are necessary.

The Effects of a Gentle Yoga Program on Sleep, Mood, and Blood Pressure in Older Women with Restless Legs Syndrome (RLS): A Preliminary Randomized Controlled Trial

Objective. To examine the effects of yoga versus an educational film program on sleep, mood, perceived stress, and sympathetic activation in older women with RLS. Methods. Participants were drawn from a larger trial regarding the effects of yoga on cardiovascular disease risk profiles in overweight, sedentary postmenopausal women. Seventy-five women were randomized to receive either an 8-week yoga (n = 38) or educational film (n = 37) program. All 75 participants completed an RLS screening questionnaire. The 20 women who met all four diagnostic criteria for RLS (n = 10 yoga, 10 film group) comprised the population for this nested study. Main outcomes assessed pre- and post-treatment included: sleep (Pittsburgh Sleep Quality Index), stress (Perceived Stress Scale), mood (Profile of Mood States, State-Trait Anxiety Inventory), blood pressure, and heart rate. Results. The yoga group demonstrated significantly greater improvements than controls in multiple domains of sleep quality and mood, and significantly greater reductions in insomnia prevalence, anxiety, perceived stress, and blood pressure (all P's≤0.05). Adjusted intergroup effect sizes for psychosocial variables were large, ranging from 1.9 for state anxiety to 2.6 for sleep quality. Conclusions. These preliminary findings suggest yoga may offer an effective intervention for improving sleep, mood, perceived stress, and blood pressure in older women with RLS.

Sleep-related movement disorders

Several movement disorders may occur during nocturnal rest disrupting sleep. A part of these complaints is characterized by relatively simple, non-purposeful and usually stereotyped movements. The last version of the International Classification of Sleep Disorders includes these clinical conditions (i.e. restless legs syndrome, periodic limb movement disorder, sleep-related leg cramps, sleep-related bruxism and sleep-related rhythmic movement disorder) under the category entitled sleep-related movement disorders. Moreover, apparently physiological movements (e.g. alternating leg muscle activation and excessive hypnic fragmentary myoclonus) can show a high frequency and severity impairing sleep quality. Clinical and, in specific cases, neurophysiological assessments are required to detect the presence of nocturnal movement complaints. Patients reporting poor sleep due to these abnormal movements should undergo non-pharmacological or pharmacological treatments.

Pediatric restless legs syndrome: analysis of symptom descriptions and drawings

The specific aims of this study were to collect and analyze detailed symptom descriptions from patients with pediatric restless legs syndrome, ages 6 to 17 years, as well as assess symptom impact and the usefulness of drawings. Trained qualitative interviewers conducted face-to-face audio-recorded interviews of children and adolescents who met criteria for definite restless legs syndrome. Thirty-three patients in 3 age groups used 16 different categories of descriptors for restless legs sensations, with a mean of 3 or more categories used per patient in each age group. "Need to move/kick," "pain/hurts," "uncomfortable/cannot get comfortable," and "like bugs or ants/crawling" were the most common descriptors. Two-thirds reported daytime sensations, and nearly half had arm involvement. They described impact on sleep, cognitive function, and affect. Drawings provided useful diagnostic information. These detailed empirical data will be useful in clinical practice, as well as in the development of formal diagnostic tools and severity measures.

Restless legs syndrome and hypertension in middle-aged women

Limited research suggests a relationship between restless legs syndrome and hypertension. We, therefore, assessed the relationship between restless legs syndrome and hypertension among middle-aged women. This is a cross-sectional study including 65 544 women (aged 41-58 years) participating in Nurses' Health Study II. The participants with diabetes mellitus and arthritis were excluded, because these conditions can mimic restless legs syndrome. Restless legs syndrome was assessed by a self-administered questionnaire based on the International Restless Legs Study Group criteria. Information on diagnosis of hypertension and blood pressure values were collected via questionnaires. Multivariable logistic regression models were used to analyze the relation between restless legs syndrome and hypertension, with adjustment for age, race, body mass index, physical activity, menopausal status, smoking, use of analgesics, and intake of alcohol, caffeine, folate, and iron. Compared with women with no restless legs symptoms, the multiple adjusted odds of having hypertension were 1.20 times (95% CI: 1.10-1.30; P<0.0001) higher among women with restless legs symptoms. The adjusted odds ratios for women who reported restless legs symptoms 5 to 14 times per month and ≥15 times per month were 1.06 (95% CI: 0.94-1.18) and 1.41 (95% CI: 1.24-1.61) respectively, compared with those without the symptoms (P trend: <0.0001). Greater frequency of restless legs symptoms was associated with higher concurrent systolic and diastolic blood pressures (P trend: <0.0001 for both). Women with restless legs syndrome have a higher prevalence of hypertension, and this prevalence increases with more frequent restless legs symptoms.

Genetics of sleep and sleep disorders

Sleep remains one of the least understood phenomena in biology--even its role in synaptic plasticity remains debatable. Since sleep was recognized to be regulated genetically, intense research has launched on two fronts: the development of model organisms for deciphering the molecular mechanisms of sleep and attempts to identify genetic underpinnings of human sleep disorders. In this Review, we describe how unbiased, high-throughput screens in model organisms are uncovering sleep regulatory mechanisms and how pathways, such as the circadian clock network and specific neurotransmitter signals, have conserved effects on sleep from Drosophila to humans. At the same time, genome-wide association studies (GWAS) have uncovered ∼14 loci increasing susceptibility to sleep disorders, such as narcolepsy and restless leg syndrome. To conclude, we discuss how these different strategies will be critical to unambiguously defining the function of sleep.

Update on sleep and its disorders

Inadequate sleep and sleep disorders have important adverse consequences on multiple systems. This review covers three areas: (a) Genetic determinants of sleep disorders. Common gene variants with small effects have been identified for both restless legs syndrome and narcolepsy with cataplexy. Rare variants with large effects have been found in familial phase advance syndrome and in subjects with short sleep durations. (b) Obstructive sleep apnea (OSA). OSA is an oxidative stress disorder. Prospective cohort studies show an increased risk of cardiovascular events in patients with untreated severe OSA. (c) The impact of sleep disorders on obesity and diabetes. Inadequate sleep results in changes in insulin resistance and in hormone levels leading to increases in appetite. Hence, inadequate sleep is associated with development of obesity. OSA is also an independent risk factor for insulin resistance; treatment of OSA can improve insulin sensitivity.

Depression in patients with rheumatoid arthritis: description, causes and mechanisms

Two sets of contributory factors to depression among patients with rheumatoid arthritis (RA) are generally examined - the social context of the individual and the biologic disease state of that person's RA. This article will review the evidence for both. RA affects patients both physically and psychologically. Comorbid depression is common with RA and leads to worse health outcomes. Low socioeconomic status, gender, age, race/ethnicity, functional limitation, pain and poor clinical status have all been linked to depression among persons with RA. Systemic inflammation may also be associated with, cause, or contribute to depression in RA. Understanding the socioeconomic factors, individual patient characteristics and biologic causes of depression in RA can lead to a more comprehensive paradigm for targeting interventions to eliminate depression in RA.

Systemic Lupus and Risk of Restless Legs Syndrome

Objective.

To determine the prevalence of restless legs syndrome (RLS) in women with systemic lupus erthythematosus (SLE), and to compare this to a rheumatic disease sample without SLE.

Methods.

Unselected consecutive female patients were SLE were recruited from a lupus clinic. A RLS questionnaire based on 4 criteria, validated by the International Restless Legs Syndrome Study Group, was administered during a face-to-face interview. Smoking history and height and weight data were collected. Similar methods were used to determine RLS prevalence in a comparator group of women with rheumatic diseases other than SLE. Controls were frequency-matched by age group (in 5-year age bands) to SLE subjects. Controls were otherwise unselected.

Results.

We recruited 33 women with SLE and 32 controls. Twelve of 33 female SLE subjects scored positively for RLS (37.5%; 95% CI 22.9, 54.7) compared to 4 of 32 controls (12.5%; 95% CI 5.0, 28.1). Multivariate logistic regression showed that adjusted for age, obesity, and smoking, women with SLE were more likely to have RLS than the female controls (adjusted odds ratio 6.61, 95% CI 1.52, 28.77). In our multivariate analyses of all rheumatic patients, including SLE, the adjusted OR for obesity and RLS was 5.14 (95% CI 1.07, 24.6).

Conclusion.

These novel data indicate that RLS is more prevalent in women with SLE than in controls. Although obesity was a significant risk factor for RLS in our sample, the predictive covariates examined were limited.

Genome-wide association studies of sleep disorders

Sleep disorders tend to be complex diseases, with multiple genes and environmental factors interacting to contribute to phenotypes. Our understanding of the genetic underpinnings of sleep disorders has benefited from recent genome-wide association studies (GWAS). We review principles underlying GWAS and discuss recent GWAS for restless legs syndrome and narcolepsy. These studies have identified four gene variants associated with restless legs syndrome (BTBD9, MEIS1, MAP2K5/LBXCOR1, and PTPRD) and two variants associated with narcolepsy (one in the T-cell receptor α locus and another between CPT1B and CHKB). These discoveries have opened new lines of research to understand the pathophysiology of these disorders. In addition to GWAS, we expect that new technologies, such as next-generation sequencing, and continued use of animal models will provide important contributions to our understanding of the genetic basis of sleep disorders.

Iron deficiency: beyond anemia

Iron deficiency is the most common nutritional disorder affecting at least one third of world's population. Though anemia is common manifestation of iron deficiency, other effects of iron deficiency on various tissues, organs and systems are usually under recognized. Impaired brain development and cognitive, behavioural and psychomotor impairment are most worrisome manifestations of iron deficiency. Studies have demonstrated that some of these changes occurring during period of brain growth spurt (<2 years age) may be irreversible. Association of iron deficiency with febrile seizures, pica, breath holding spells, restless leg syndrome and thrombosis is increasingly being recognized. Impaired cell-mediated immunity and bactericidal function are generally noted in iron-deficient persons; however, the findings are inconsistent. Despite proven reversible functional immunological defects in vitro studies, a clinically important relationship between states of iron deficiency and susceptibility to infections remains controversial. Studies from malaria endemic regions have reported increased incidence of malaria in association with iron supplementation. These and some other aspects of iron deficiency are reviewed in this article.

Ropinirole in restless legs syndrome and periodic limb movement disorder

Restless legs syndrome and periodic limb movement disorder of sleep are now recognized as prevalent, distinct, yet overlapping disorders affecting all age groups. Although delineation of the mechanisms underlying these disorders continues to be the focus of very intense research efforts, it has become apparent that there is a prominent role for dopaminergic agents in the clinical management of these patients. Among the various dopaminergic drugs, ropinirole has undergone relatively intense and critical scrutiny, and appears to provide a safe and efficacious treatment option for patients with these two conditions. The more recent development of a controlled formulation for this drug is likely to yield additional benefits such as improved adherence and reduced fluctuations in daytime and nighttime symptoms. However, there is not enough evidence at this time to support such assumption.

No significance of the COMT val158met polymorphism in restless legs syndrome

The catechol-O-methyltransferase (COMT) val(158)met polymorphism, which codes for the substitution of valine (val) by methionine (met) leading to a reduced COMT activity in homo- or heterozygous individuals, is associated with individual pain sensitivity and dopaminergic responses in Parkinson's disease as well as with various chronic painful diseases. Recent investigations support the notion of an alteration of the medial pain pathway as well as of the descending inhibitory control system in restless legs syndrome (RLS), that both involve dopaminergic transmission as well. Thus, the distribution of the COMT val(158)met polymorphism was assessed in 298 RLS patients and compared with 135 healthy controls in relation to sex, age of onset and family history. The data revealed no significant differences in the distribution of the COMT val(158)met polymorphism in RLS patients compared with the control group, also when the heterozygous and the homozygous group containing the (158)met allele were combined. In addition, sex, age of onset and family history were not associated with the COMT val(158)met polymorphism in this German population of RLS patients. The present study adds to previous mostly negative investigations on the genetic determination of dopaminergic transmission in RLS, which have - so far - only detected an association of the MAO-A activity and RLS in females in a French-Canadian population. Further investigations assessing the different COMT haplotypes and experimental and clinical parameters are nevertheless warranted.