Genome-wide meta-analyses of restless legs syndrome yield insights into genetic architecture, disease biology and risk prediction

Restless legs syndrome (RLS) affects up to 10% of older adults. Their healthcare is impeded by delayed diagnosis and insufficient treatment. To advance disease prediction and find new entry points for therapy, we performed meta-analyses of genome-wide association studies in 116,647 individuals with RLS (cases) and 1,546,466 controls of European ancestry. The pooled analysis increased the number of risk loci eightfold to 164, including three on chromosome X. Sex-specific meta-analyses revealed largely overlapping genetic predispositions of the sexes (rg = 0.96). Locus annotation prioritized druggable genes such as glutamate receptors 1 and 4, and Mendelian randomization indicated RLS as a causal risk factor for diabetes. Machine learning approaches combining genetic and nongenetic information performed best in risk prediction (area under the curve (AUC) = 0.82-0.91). In summary, we identified targets for drug development and repurposing, prioritized potential causal relationships between RLS and relevant comorbidities and risk factors for follow-up and provided evidence that nonlinear interactions are likely relevant to RLS risk prediction.

Successful treatment of restless legs syndrome accompanied by headaches for 30 years with herbal prescriptions containing Paeoniae Radix: A case report

BACKGROUND

Restless legs syndrome (RLS) is a neurological disorder that causes unpleasant symptoms in the legs when resting, which are relieved by movement. Pharmacotherapy is the standard treatment. However, current treatment provides only symptomatic relief and may result in adverse effects with long-term use. Treatment protocols using herbal medicines have emerged to compensate for this limitation.

CASE PRESENTATION

A 70-year-old Asian woman visited our hospital with worsening headaches that had persisted for 30 years. Her headaches were aggravated by night-time lower-extremity discomfort. The patient was diagnosed with RLS based on the 2012 Revised International Restless Leg Syndrome Study Group Diagnostic Criteria (IRIS). The patient was prescribed herbal medicines, Shihogyeji-tang, Gyejibokryeong-hwan, and Jakyakgamcho-tang, all of which contain Paeoniae Radix. Fourteen days after starting herbal medicine treatment, the IRIS score decreased from 30 to 18. The patient experienced less leg discomfort. Moreover, her sleep time increased, and her headaches resolved. After 28 days of herbal treatment, the IRIS score decreased to 9. Importantly, the patient reported no sleep disturbance or headaches. Subsequently, conventional medications were discontinued. The patient remained stable (IRIS score: 9-10). Herbal treatment was discontinued on day 163. At the last follow-up, (day 364), the patient has not reported any symptom recurrence.

CONCLUSIONS

We described a female patient with a 30-year history of RLS symptoms and related sleep disturbances that induced chronic uncontrolled headaches, who experienced improvements shortly after using herbal medicines containing Paeoniae Radix. Conventional medications were discontinued and the patient had no recurrence of symptoms. Considering these, herbal medicines containing Paeoniae Radix may be a suitable alternative treatment for RLS and its related symptoms.

Agony of akathisia: a case of sodium valproate-induced akathisia

Akathisia is a subjective feeling of restlessness that often results in a compulsion to move. Drug-related causes are the most common aetiologies. It can often be confused with restless legs syndrome (RLS). We describe a case of valproate-induced akathisia that improved with drug cessation. This case reports a rare but treatable adverse effect of sodium valproate and highlights the importance of differentiating akathisia from RLS.

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

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

Effectiveness of exercise and pramipexole in the treatment of restless leg syndrome: Implications on the dopaminergic system and PTPRD

OBJECTIVE

Dopaminergic dysfunction, iron reduction and variations in the PTPRD gene (protein tyrosine phosphatase receptor type delta) may be associated with restless leg syndrome (RLS). Here, we evaluate the effect of pramipexole (PPX) and exercise on genes and proteins associated with RLS and on sleep patterns in spontaneously hypertensive rats (SHR).

METHODS

Animals were distributed into 4 groups: 1) Control (CTRL); 2) Exercise (EX); 3) Exercise and pramipexole (EX + PPX); and 4) Pramipexole (PPX). PPX treatment was performed daily (0.125 mg/kg), while exercise was conducted over 5 sessions per week, both for 4 weeks.

RESULTS

EX + PPX increased the protein levels of PTPRD, reduced the protein levels of the enzyme tyrosine hydroxylase (TH) and improved sleep parameters in both cycles; on the other hand, the use of PPX reduced mRNA and protein levels of PTPRD and TH but improved the sleep pattern in the light cycle. However, in the dark cycle, pramipexole caused the worsening of symptoms.

CONCLUSIONS

We suggest that the improvement in sleep pattern by EX + PPX may be associated with the increased protein levels of PTPRD and that EX + PPX can reverse the negative effects of PPX.

Neurological Insights into Sleep Disorders in Parkinson's Disease

Parkinson's disease (PD) is a common multidimensional neurological disorder characterized by motor and non-motor features and is more prevalent in the elderly. Sleep disorders and cognitive disturbances are also significant characteristics of PD. Sleep is an important physiological process for normal human cognition and physical functioning. Sleep deprivation negatively impacts human physical, mental, and behavioral functions. Sleep disturbances include problems falling asleep, disturbances occurring during sleep, abnormal movements during sleep, insufficient sleep, and excessive sleep. The most recognizable and known sleep disorders, such as rapid-eye-movement behavior disorder (RBD), insomnia, excessive daytime sleepiness (EDS), restless legs syndrome (RLS), sleep-related breathing disorders (SRBDs), and circadian-rhythm-related sleep-wake disorders (CRSWDs), have been associated with PD. RBD and associated emotional disorders are common non-motor symptoms of PD. In individuals, sleep disorders and cognitive impairment are important prognostic factors for predicting progressing neurodegeneration and developing dementia conditions in PD. Studies have focused on RBD and its associated neurological changes and functional deficits in PD patients. Other risks, such as cognitive decline, anxiety, and depression, are related to RBD. Sleep-disorder diagnosis is challenging, especially in identifying the essential factors that disturb the sleep-wake cycle and the co-existence of other concomitant sleep issues, motor symptoms, and breathing disorders. Focusing on sleep patterns and their disturbances, including genetic and other neurochemical changes, helps us to better understand the central causes of sleep alterations and cognitive functions in PD patients. Relations between α-synuclein aggregation in the brain and gender differences in sleep disorders have been reported. The existing correlation between sleep disorders and levels of α-synuclein in the cerebrospinal fluid indicates the risk of progression of synucleinopathies. Multidirectional approaches are required to correlate sleep disorders and neuropsychiatric symptoms and diagnose sensitive biomarkers for neurodegeneration. The evaluation of sleep pattern disturbances and cognitive impairment may aid in the development of novel and effective treatments for PD.

A Randomized, Open Label, Exploratory Trial Comparing Efficacy of Amantadine and Ropinirole in Restless Legs Syndrome

Objective  Amantadine has both anti-glutamatergic and dopaminergic action and may improve restless legs syndrome (RLS). We compared the efficacy and adverse-effect profile of amantadine and ropinirole in RLS. Methods  In this randomized, open-label, 12-week flexible-dose exploratory study, RLS patients with international RLS study group severity scale score (IRLSS) > 10 were randomized to receive either amantadine(100-300mg/day) or ropinirole (0.5-2mg/day). Drug dose was increased until week-6 if IRLSS failed to improve by ≥10% of previous visit score. IRLSS change from baseline at week-12 was the primary outcome. Secondary outcomes included change in RLS-related quality of life (RLS-QOL) and insomnia severity index (ISI), along with clinical-global-impression of change/improvement (CGI-I), and proportion of patients with adverse-effects and resulting discontinuation. Results  Twenty-four patients received amantadine and 22 received ropinirole. Both groups had a significant effect for visit*treatment arm (F (2.19,68.15) =4.35;P = 0.01). With a similar baseline IRLSS, both intention-to-treat (ITT) and per-protocol analyses revealed comparable IRLSS until week-8, with ropinirole appearing superior from week-10 to week-12 (week-12 IRLSS, amantadine vs ropinirole:17.0  ±   5.7 vs 9.0  ±   4.4;P < 0.001). ITT analysis at week-12 showed comparable proportion of responders (≥10% IRLSS reduction) in both groups (P = 0.10). Both drugs improved sleep and QOL, but week-12 scores favoured ropinirole [(ISI:14.4  ±   5.7 vs 9.4  ±   4.5; P = 0.001) ;(RLS-QOL:70.4  ±   17.9 vs 86.5  ±   9.8; P = 0.005)]. CGI-I at week-12 favoured ropinirole (Mann-Whitney U = 35.50, S. E = 23.05;P = 0.01). Four patients in amantadine and two in ropinirole group developed adverse effects, with resulting discontinuation in two patients on amantadine. Conclusions  The present study reports equivalent reduction in RLS symptoms with both amantadine and ropinirole until week-8, with the latter being superior from week-10 onwards. Ropinirole was better tolerated.

Restless Legs Syndrome in Chronic Kidney Disease- a Systematic Review

Objectives

The objective of this review is to provide updated information on the epidemiology, correlating factors and treatment of chronic kidney disease associated restless legs syndrome (CKD-A-RLS) in both adult and pediatric population.

Materials and Methods

We have reviewed the Medline search and Google Scholar search up to May 2022, using key words restless legs syndrome, chronic kidney disease and hemodialysis and kidney transplant. The reviewed articles were studied for epidemiology, correlating factors, as well as pharmacologic and non-pharmacologic treatment options.

Results

Our search revealed 175 articles, 111 were clinical trials or cross- sectional studies and 64 were review articles. All 111 articles were retrieved and studied in detail. Of these, 105 focused on adults and 6 on children. A majority of studies on dialysis patients reported a prevalence between 15-30%, which is notably higher than prevalence of RLS in general population (5-10%). The correlation between presence of CKD-A-RLS with age, gender, abnormalities of hemogram, iron, ferritin, serum lipids, electrolytes and parathyroid hormones were also reviewed. The results were inconsistent and controversial. Limited studies have reported on the treatment of CKD-A-RLS. Non-pharmacological treatment focused on the effect(s) of exercise, acupuncture, massage with different oils and infra-red light whereas, pharmacologic treatment options include the effects of dopaminergic drugs, Alpha2-Delta ligands (gabapentin and pregabalin), vitamins E and C, and intravenous iron infusion.

Conclusion

This updated review showed that RLS is two to three times more common in patients with CKD compared to the general population. More patients with CKD-A-RLS demonstrated increased mortality, increased incidence of cardiovascular accident, depression, insomnia and impaired quality of life than those with CKD without RLS. Dopaminergic drugs such as levodopa, ropinirole, pramipexole and rotigotine as well as calcium channel blockers (gabapentin and pregabalin) are helpful for treatment of RLS. High quality studies with these agents are currently underway and hopefully confirm the efficacy and practicality of using these drugs in CKD-A-RLS. Some studies have shown that aerobic exercise and massage with lavender oil can improve symptoms of CKD-A- RLS suggesting that these measures can be useful as adjunct therapy.

Dramatic Responses to Low-Dose Pramipexole in Painful Legs and Moving Toes Syndrome

Painful legs and moving toes syndrome (PLMTS) is a rare movement disorder characterized by spontaneous abnormal, involuntary toe movements and unilateral or bilateral lower extremity pain that predominantly affects women in middle age or later. The background etiology of PLMTS includes peripheral neuropathy, a history of trauma, and nerve root damage, but the cause of the disease is often undetermined. The pain usually occurs first and is often more distressing to the patient than abnormal toe movement. Spontaneous resolution is rare, and symptomatic therapies include the oral administration of anticonvulsants, antidepressants, and various pain relievers, as well as other therapeutic interventions, including botulinum toxin injection and epidural block, but their effectiveness is uncertain. We report a case of PMLTS in which low doses of pramipexole, a non-ergot dopamine agonist, dramatically improved both abnormal toe movement and leg pain, which are documented by videography.

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.

Clonazepam for the management of sleep disorders

BACKGROUND

The objectives of this review and meta-analysis of polysomnographic data are those to focus on the clinical use of clonazepam for the management of sleep disorders by re-analyzing clinical trials and randomized clinical trials which have been published in peer-reviewed journals.

METHODS

A review of the literature including clinical trials and randomized controlled trials was performed in PubMed®, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement protocol. A random effects model meta-analysis was then carried out for the four more frequently reported polysomnographic measures: total sleep time, sleep latency, sleep efficiency, and periodic leg movement during sleep (PLMS) index.

RESULTS

A total of 33 articles were retrieved and screened in full text, of which 18 met the criteria for review; among the latter, nine met the criteria for meta-analysis. The studies included in the review involved patients with insomnia, REM sleep behavior disorder, sleep bruxism, and restless leg syndrome or PLMS which reported, most often, an increase in total sleep time with clonazepam. A clear sleep-promoting effect of clonazepam was found also by meta-analysis.

DISCUSSION AND CONCLUSIONS

Our results indicate that the pharmacological treatment of sleep disorders with clonazepam must always be personalized according to the type of patient, the risk of addiction and the concomitant presence of respiratory disorders are key factors to take into account. However, in light of the clinical evidence of the few studies in the literature on the different types of disorders, more studies on the use of clonazepam (also in association with first choice treatments) are definitely needed.

Effects of bupropion and SSRI antidepressants on leg movement activity and chin muscle tone during sleep in adolescents

STUDY OBJECTIVES

To evaluate the effects of bupropion on periodic limb movements during sleep (PLMS) and chin electromyography tone in children taking it for their mood disorder, compared to the effects of selective serotonin reuptake inhibitors (SSRIs) and of bupropion combined with SSRIs.

METHODS

Six adolescents (aged 16.0 ± 0.63 years) taking bupropion alone and 6 adolescents (aged 15.9 ± 1.36 years) taking bupropion in combination with an SSRI antidepressant were recruited, along with 10 adolescents (aged 16.2 ± 0.2 years) taking different SSRIs, and they were also enrolled together with 17 age- and sex-matched control patients (aged 15.5 ± 1.26 years). Polysomnographic studies were obtained, and participants' leg movement activity during sleep and muscle tone were assessed quantitatively (atonia index) during all sleep stages.

RESULTS

Participants taking SSRIs showed PLMS indices significantly higher than those of control patients, whereas adolescents taking bupropion showed only slightly increased indexes of nonperiodic leg movements during sleep. No differences in PLMS were observed between adolescents taking bupropion alone or in association with SSRIs. The atonia index showed, within each sleep stage, the lowest values in the 2 groups taking SSRIs and the highest in the control patients; adolescents taking bupropion alone tended to show values slightly smaller than those of the control patients.

CONCLUSIONS

We found that similar to adults, in adolescents SSRIs but not bupropion are associated with increased PLMS. Bupropion also seems to counteract the SSRI-induced increase of PLMS, when administered in combination; thus, the dopaminergic effect of bupropion seems to outmatch the antidopaminergic action of SSRIs. Conversely, bupropion does not counteract the effects of SSRIs on chin electromyography tone.

CITATION

DelRosso LM, Mogavero MP, Fickensher A, Bruni O, Schenck CH, Ferri R. Effects of bupropion and SSRI antidepressants on leg movement activity and chin muscle tone during sleep in adolescents. J Clin Sleep Med. 2023;19(1):151-161.

Putative Animal Models of Restless Legs Syndrome: A Systematic Review and Evaluation of Their Face and Construct Validity

Restless legs syndrome (RLS) is a sensorimotor disorder that severely affects sleep. It is characterized by an urge to move the legs, which is often accompanied by periodic limb movements during sleep. RLS has a high prevalence in the population and is usually a life-long condition. While its origins remain unclear, RLS is initially highly responsive to treatment with dopaminergic agonists that target D2-like receptors, in particular D2 and D3, but the long-term response is often unsatisfactory. Over the years, several putative animal models for RLS have been developed, mainly based on the epidemiological and neurochemical link with iron deficiency, treatment efficacy of D2-like dopaminergic agonists, or genome-wide association studies that identified risk factors in the patient population. Here, we present the first systematic review of putative animal models of RLS, provide information about their face and construct validity, and report their role in deciphering the underlying pathophysiological mechanisms that may cause or contribute to RLS. We propose that identifying the causal links between genetic risk factors, altered organ functions, and changes to molecular pathways in neural circuitry will eventually lead to more effective new treatment options that bypass the side effects of the currently used therapeutics in RLS, especially for long-term therapy.

Does Dexmedetomidine Improve or Worsen Restless Leg Syndrome under Sedation: A Case Report and Extensive Review

Background

Restless leg syndrome (RLS) is a common neurological condition that manifests as creeping, nonpainful urges to move lower extremities and is relieved with movements of the legs. RLS is associated with comorbidities such as gastric surgery, diabetes mellitus, uremia, and iron deficiency anemia, and it is misdiagnosed in many cases. Drugs like levodopa, ropinirole, pramipexole, cabergoline, and pergolide that target the dopaminergic system have been traditionally used to treat symptoms of RLS. α2-adrenoceptor (α2-AR) agonists, like clonidine and dexmedetomidine, have also been reported to show improvement of RLS symptoms during sedation. Specific Aim. This case report suggests that dexmedetomidine may have worsened RLS during sedation in a 71-year-old male with no prior diagnosis of RLS or reported symptoms. The patient had a procedure for right first metatarsophalangeal joint (MTPJ) fusion, with second digit proximal interphalangeal joint (PIPJ) arthrodesis, and flexor tendon transfer due to pain on walking and failing conservative therapy. He underwent intravenous sedation/monitored anesthesia care (MAC) with propofol, dexmedetomidine, and a peripheral regional block for intraoperative anesthesia and postoperative analgesia. During the surgery, the patient experienced continuous bilateral leg movement, unpredictable, and unrelated to surgical stimulation or level of consciousness within 5 minutes of administration of dexmedetomidine. The patient tolerated the procedure, and the unpredicted leg movement was managed by the surgeons intraoperatively.

Conclusion

Although no previous literature exists and mechanisms are unclear, this case report hypothesizes that dexmedetomidine may contribute to worsening RLS symptoms.

The Prevalence and Predictors of Restless Legs Syndrome in Patients with Liver Cirrhosis

Introduction and aim. Sleep disorders are highly prevalent in patients with liver cirrhosis. The aim of this study was to investigate the prevalence of restless legs syndrome (RLS), as well as its risk factors and possible predictors, in a cohort of patients with liver cirrhosis. Material and methods. We performed a cross-sectional prospective study over a period of 14 months and enrolled 69 patients with liver cirrhosis, after applying the inclusion and exclusion criteria. The cases of RLS were assessed according to the International Restless Legs Syndrome Study Group (IRLSSG) criteria and severity scale. Results. Out of the total number of patients, 55% fulfilled the criteria for RLS. Age, diabetes, severity of cirrhosis, serum creatinine, glomerular filtration rate (GFR), and mean hemoglobin were associated with the presence of RLS. Moreover, there was a significantly higher prevalence of RLS among patients with decompensated cirrhosis. From all the risk factors introduced into the multivariate analysis, only the GFR could predict the presence of RLS. Conclusions. This research shows that patients with liver cirrhosis have a high risk of RLS. Even though there are multiple risk factors associated with RLS, only the GFR could predict its occurrence in our cohort.

Restless Legs Syndrome Prevalence and Clinical Correlates Among Psychiatric Inpatients: A Multicenter Study

Background

There are only limited reports on the prevalence of restless legs syndrome (RLS) in patients with psychiatric disorders. The present study aimed to evaluate the prevalence and clinical correlates in psychiatric inpatients in Germany and Switzerland.

Methods

This is a multicenter cross-sectional study of psychiatric inpatients with an age above 18 years that were diagnosed and evaluated face-to-face using the International RLS Study Group criteria (IRLSSG) and the International RLS severity scale (IRLS). In addition to sociodemographic and biometric data, sleep quality and mood were assessed using the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), the Epworth Sleepiness Scale (ESS), and the Patient Health Questionnaire (PHQ-9). In addition to univariate statistics used to describe and statistically analyze differences in variables of interest between patients with and without RLS, a logistic model was employed to identify predictors for the occurrence of RLS.

Results

The prevalence of RLS in a sample of 317 psychiatric inpatients was 16.4%, and 76.9% of these were diagnosed with RLS for the first time. RLS severity was moderate to severe (IRLS ± SD: 20.3 ± 8.4). The prevalences in women (p = 0.0036) and in first-degree relatives with RLS (p = 0.0108) as well as the body mass index (BMI, p = 0.0161) were significantly higher among patients with RLS, while alcohol consumption was significantly lower in the RLS group. With the exception of atypical antipsychotics, treatment with psychotropic drugs was not associated with RLS symptoms. Regarding subjective sleep quality and mood, scores of the PSQI (p = 0.0007), ISI (p = 0.0003), and ESS (p = 0.0005) were higher in patients with RLS, while PHQ-9 scores were not different. A logistic regression analysis identified gender (OR 2.67; 95% CI [1.25; 5.72]), first-degree relatives with RLS (OR 3.29; 95% CI [1.11; 9.73], ESS score (OR 1.09; 95% CI [1.01; 1.17]), and rare alcohol consumption (OR 0.45; 95% CI [0.22; 0.94] as predictors for RLS.

Conclusions

Clinically significant RLS had a high prevalence in psychiatric patients. RLS was associated with higher BMI, impaired sleep quality, and lower alcohol consumption. A systematic assessment of restless legs symptoms might contribute to improve the treatment of psychiatric patients.

[Sleep medicine in psychiatry and psychotherapy]

Sleep medicine is a cross-disciplinary subject with high relevance for psychiatry and psychotherapy. The three most common sleep disorders (insomnia, sleep apnea syndrome and restless legs syndrome) are presented here with practical relevance. Cognitive behavioral therapy is the treatment of choice for insomnia, whereas symptomatic drug treatment (especially with GABA receptor agonists) should be used with caution. Sleep-related breathing disorders have a high prevalence of around 24% among psychiatric inpatients in Germany. Typical symptoms of obstructive sleep apnea syndrome should lead to a staged diagnostic process and, if necessary, cardiorespiratory polysomnography. It is not unusual for restless legs syndrome to be caused by psychopharmacological treatment. The primary form was usually treated with dopamine or dopamine agonists but due to the risk of augmentation, alternatives should be considered more often.

Pramipexole treatment attenuates mechanical hypersensitivity in male rats experiencing chronic inflammatory pain

Opioids are commonly prescribed for pain despite growing evidence of their low efficacy in the treatment of chronic inflammatory pain and the high potential for misuse. There is a clear need to investigate non-opioid alternatives for the treatment of pain. In the present study, we tested the hypothesis that acute and repeated dopamine agonist treatment would attenuate mechanical hypersensitivity in male Long-Evans rats experiencing chronic inflammatory pain. We used two clinically available therapeutics, l-DOPA (precursor of dopamine biosynthesis) and pramipexole (dopamine D2/3 receptor agonist), to examine the functional role of dopamine signaling on mechanical hypersensitivity using an animal model of chronic inflammatory pain (complete Freund's adjuvant, CFA). We found that both acute and repeated pramipexole treatment attenuated hyperalgesia-like behavior in CFA-treated animals but exhibited no analgesic effects in control animals. In contrast, there was no effect of acute or repeated l-DOPA treatment on mechanical hypersensitivity in either CFA- or saline-treated animals. Notably, we discovered some extended effects of l-DOPA and pramipexole on decreasing pain-like behavior at three days and one week post-drug treatment. We also examined the effects of pramipexole treatment on glutamatergic and presynaptic signaling in pain- and reward-related brain regions including the nucleus accumbens (NAc), dorsal striatum (DS), ventral tegmental area (VTA), cingulate cortex (CC), central amygdala (CeA), and periaqueductal gray (PAG). We found that pramipexole treatment decreased AMPA receptor phosphorylation (pGluR1845) in the NAc and DS but increased pGluR1845 in the CC and CeA. A marker of presynaptic vesicle release, pSynapsin, was also increased in the DS, VTA, CC, CeA, and PAG following pramipexole treatment. Interestingly, pramipexole increased pSynapsin in the NAc of saline-treated animals, but not CFA-treated animals, suggesting blunted presynaptic vesicle release in the NAc of CFA-treated animals following pramipexole treatment. To examine the functional implications of impaired presynaptic signaling in the NAc of CFA animals, we used ex vivo electrophysiology to examine the effects of pramipexole treatment on the intrinsic excitability of NAc neurons in CFA- and saline-treated animals. We found that pramipexole treatment reduced NAc intrinsic excitability in saline-treated animals but produced no change in NAc intrinsic excitability in CFA-treated animals. These findings indicate alterations in dopamine D2/3 receptor signaling in the NAc of animals with a history of chronic pain in association with the anti-hyperalgesic effects of pramipexole treatment.

Dopamine D2L receptor density influences the recruitment of β-arrestin2 and Gi1 induced by antiparkinsonian drugs

INTRODUCTION

Brain imaging studies have highlighted that the density of dopamine D₂ receptors markedly fluctuates across the stages of Parkinson's disease and in response to pharmacological treatment. Moreover, receptor density constitutes a molecular determinant for the signaling profile of D₂ receptor ligands. We therefore hypothesized that variations in receptor expression could influence D₂ receptor response to antiparkinsonian drugs, most notably with respect to the recruitment bias between G_i1 and β-arrestin2.

METHODS

The recruitment bias of dopamine, pramipexole, ropinirole, and rotigotine was examined using a nanoluciferase-based biosensor for probing the interactions of the D_2L receptor with either G_i1 or β-arrestin2. The characterization of the functional selectivity of these D₂ receptor agonists was performed at two distinct D_2L receptor densities by taking advantage of a cell model carrying an inducible system that enables the overexpression of the D_2L receptor when exposed to doxycycline.

RESULTS

A high receptor density oriented the balanced signaling profile of dopamine towards a preferential recruitment of G_i1. It also moderated the marked G_i1 and β-arrestin2 biases of pramipexole and rotigotine, respectively. At variance, the G_i1 bias of ropinirole appeared as not being influenced by D_2L receptor density.

CONCLUSIONS

Taken together, these observations highlight receptor density as a key driver of the signaling transducer recruitment triggered by antiparkinsonian agents. Moreover, given the putative beneficial properties of β-arrestin2 in promoting locomotion, this study provides molecular insights that position the arrestin-biased ligand rotigotine as a putatively more beneficial D₂ receptor agonist for the treatment of early and late Parkinson's disease.

Cannabinoids for Symptom Management in Patients with Kidney Failure

People with kidney failure can experience a range of symptoms that lead to suffering and poor quality of life. Available therapies are limited, and evidence for new treatment options is sparse, often resulting in incomplete relief of symptoms. There is growing interest in the potential for cannabinoids, including cannabidiol and tetrahydrocannabinol, to treat symptoms across a wide range of chronic diseases. As legal prohibitions are withdrawn or minimized in many jurisdictions, patients are increasingly able to access these agents. Cannabinoid receptors, CB1 and CB2, are widely expressed in the body, including within the nervous and immune systems, and exogenous cannabinoids can have anxiolytic, anti-emetic, analgesic and anti-inflammatory effects. Considering their known physiological actions and successful studies in other patient populations, cannabinoids may be viewed as potential therapies for a variety of common symptoms affecting those with kidney failure, including pruritus, nausea, insomnia, chronic neuropathic pain, anorexia, and restless legs syndrome. In this review, we summarize the pharmacology and pharmacokinetics of cannabinoids, along with what is known about the use of cannabinoids for symptom relief in those with kidney disease, and the evidence available concerning their role in management of common symptoms. Presently, while these agents show varying efficacy with a reasonable safety profile in other patient populations, evidence-based prescribing of cannabinoids for people with symptomatic kidney failure is not possible. Given the symptom burden experienced by individuals with kidney failure, there is an urgent need to understand the tolerability and safety of these agents in this population, which must ultimately be followed by robust, randomized controlled trials to determine if they are effective for symptom relief.

Difference in rural and urban Medicare prescription pattern for Parkinson’s disease in Hawai‘i

Background

Medical management of Parkinson’s Disease (PD) is becoming complex. Increasing evidence suggests that patients have better outcomes when they are managed by neurologists. However, access to neurologists can be limited in rural areas. Analysis of prescription pattern can provide insight into access gap rural patients face.

Methods

This retrospective observational study used National Medicare Provider Utilization and Payment Data: Part D Prescriber Public Use Files from 2013 to 2018. Query was made for levodopa, dopamine agonists and other antiparkinsonian medications. The data elements obtained included drug name, number of prescribers, prescriber specialty, number of claims, number of standardized 30-day Part D prescriptions, and number of Medicare beneficiaries in the state of Hawai‘i. Individual prescribing providers were categorized as urban or rural based on their cities of practice. Prescription patterns of urban and rural providers in Hawai‘i as well as difference in provider specialty were compared, using standardized 30-day prescriptions as the primary measure of utilization.

Results

Practice patterns differed between rural and urban areas. In rural Hawai‘i, Rytary, Rotigoitne and selegiline were rarely prescribed. Levodopa percentage was higher in urban Hawai‘i. In urban Hawai‘i, 74.4% of the prescriptions were provided by movement disorders and general neurologists. In rural Hawai'i, 25.1% of the prescriptions were written by neurologists and 74.9% by general practitioners.

Conclusions

In the state of Hawai‘i, there is an urban–rural access gap to neurologists as evidenced by Medicare prescription pattern. Further study is needed to understand the reasons for rural–urban differences in prescription patterns and their impact on outcomes.

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

PURPOSE

This study investigated the associations of peripheral iron status with different manifestations of restless legs syndrome (RLS), including leg movements (LMs) on polysomnography (PSG), disease severity, and impact on patients.

PATIENTS AND METHODS

In this cross-sectional study, 108 patients with RLS were enrolled at Sir Run Run Shaw Hospital's Center for Sleep Medicine. Demographic information, disease characteristics, RLS severity, and impact on patients were assessed through a semi-structured questionnaire. Peripheral iron indicators [serum ferritin, iron, and transferrin concentrations; unsaturated iron-binding capacity (UIBC) and total iron-binding capacity (TIBC); transferrin saturation (TSAT)] were measured following PSG to assess sleep stages, respiratory events, microarousals and LM parameters. Data from patients with and without ferritin concentration < 50 µg/L were compared in crude analyses, and Spearman correlations of other iron indicators with RLS data were examined. An ordinal logistic regression model was used to adjust for age, sex, body mass index, years of education, age at the time of RLS onset, prior treatment (yes/no), C-reactive protein (CRP)/hemoglobin level, total sleep time and apnea-hypopnea index.

RESULTS

Multivariate analysis showed that periodic LMs during sleep (PLMS) and other LM parameters were significantly associated with a ferritin concentration < 50 µg/L, UIBC, TIBC, and serum transferrin concentration, but not serum iron or TSAT. By contrast, the severity and impact of RLS were not associated with a ferritin concentration < 50 µg/L or other peripheral iron indicators in the multivariate model.

CONCLUSION

In this study, peripheral iron status was associated mainly with motor components (LMs on PSG) rather than sensory components (severity and impact of RLS) after adequately controlling for potential confounders, such as CRP and hemoglobin levels. Commonly used peripheral iron metabolism indicators may therefore not be ideal biomarkers of RLS severity or impact on patients.

Management of Sleep Disturbances in Parkinson's Disease

Parkinson's disease (PD) is defined by its motor symptoms rigidity, tremor, and akinesia. However, non-motor symptoms, particularly autonomic disorders and sleep disturbances, occur frequently in PD causing equivalent or even greater discomfort than motor symptoms effectively decreasing quality of life in patients and caregivers. Most common sleep disturbances in PD are insomnia, sleep disordered breathing, excessive daytime sleepiness, REM sleep behavior disorder, and sleep-related movement disorders such as restless legs syndrome. Despite their high prevalence, therapeutic options in the in- and outpatient setting are limited, partly due to lack of scientific evidence. The importance of sleep disturbances in neurodegenerative diseases has been further emphasized by recent evidence indicating a bidirectional relationship between neurodegeneration and sleep. A more profound insight into the underlying pathophysiological mechanisms intertwining sleep and neurodegeneration might lead to unique and individually tailored disease modifying or even neuroprotective therapeutic options in the long run. Therefore, current evidence concerning the management of sleep disturbances in PD will be discussed with the aim of providing a substantiated scaffolding for clinical decisions in long-term PD therapy.

D3 Receptors and Restless Legs Syndrome

Restless Legs Syndrome (RLS) is a sensorimotor disorder that severely affects sleep. It is characterized by an urge to move the legs that is often accompanied by periodic limb movements during sleep (PLMS). RLS has a high prevalence in the population and is usually a life-long condition. While its origins remain unclear, RLS is initially highly responsive to treatment with dopaminergics that target the D3 receptor. However, over time patients often develop a gradual tolerance that can lead to the emergence of adverse effects and the augmentation of the symptoms. While the basal ganglia and the striatum control leg movements, the lumbar spinal cord is the gateway for the sensory processing of the symptoms and critical for the associated leg movements. D3 receptors are highly expressed in nucleus accumbens (NAc) of the striatum and the sensory-processing areas of the spinal dorsal horn. In contrast, D1 receptors are strongly expressed throughout the entire striatum and in the ventral horn of the spinal cord. Long-term treatment with D3 receptor full agonists is associated with an upregulation of the D1 receptor subtype, and D3 and D1 receptors can form functional heteromers, in which the D3R controls the D1R function. It is conceivable that the switch from beneficial treatment to augmentation observed in RLS patients after prolonged D3R agonist exposure may be the result of unmasked D1-like receptor actions.

The Efficacy and Safety of Pharmacological Treatments for Restless Legs Syndrome: Systemic Review and Network Meta-Analysis

Although various drugs are currently used for restless legs syndrome (RLS) in clinic, selecting appropriate drugs for patients is difficult. This network meta-analysis (NMA) aimed to compare the efficacy and safety of different drugs. After literature searching and screening, 46 trials, including 10,674 participants are included in this NMA. The pooled results showed that, compared with placebo, only levodopa is inefficient to relieve symptoms of RLS. Cabergoline decreases IRLS scores to the greatest extent among all drugs (MD −11.98, 95% CI −16.19 to −7.78). Additionally, pramipexole is superior to ropinirole in alleviating symptoms of RLS (MD −2.52, 95% CI −4.69 to −0.35). Moreover, iron supplement alleviates RLS symptoms significantly compared with placebo in patient with iron deficiency (MD −5.15, 95% CI −8.99 to −1.31), but not for RLS patients with normal serum ferritin level (MD −2.22, 95% CI −6.99 to 2.56). For primary RLS, these drugs are also effective, while there is insufficient data to analyze drug efficacy in secondary RLS. We analyzed risk of common adverse effects of drugs including nausea, somnolence, fatigue, headache and nasopharyngitis. Alpha-2-delta ligands and DAs are favorable choices for both primary and secondary RLS because of their significant efficacy and good tolerability. Iron supplement can significantly alleviate symptoms of RLS patients with iron deficiency than placebo. We recommend gabapentin, gabapentin enacarbil, and pregabalin for clinicians for first consideration mainly because that they rarely cause augmentation. Oxycodone-naloxone could be considered in patients with severe or very severe RLS who failed in treatment with above drugs.

Investigating the inflammation marker neutrophil-to-lymphocyte ratio in Danish blood donors with restless legs syndrome

Background

Restless Legs Syndrome (RLS) is a neurological sensorimotor disorder that occurs in the evening and night, thereby impacting quality of sleep in sufferers. The pathophysiology of RLS is poorly understood but inflammation has been proposed as possibly being involved. The neutrophil-to-lymphocyte ratio (NLR) can be used as an inflammation marker but results from small studies have been inconclusive in determining whether NLR is associated with RLS. We aimed to assess whether an association between NLR and RLS exists in a large cohort of healthy individuals.

Methods

Neutrophils and lymphocytes were measured in blood samples of 13,055 individuals from the Danish Blood Donor Study, all of whom completed the validated Cambridge-Hopkins RLS-questionnaire for RLS assessment.

Results

In the sample, 661 individuals were determined as current RLS cases (5.1%). A higher proportion of individuals with RLS were females (62.5% vs 47.5%; P<0.001) and RLS cases were older than controls (P<0.001), but no differences in body mass index (BMI), smoking or alcohol consumption were found between the two groups. An increased NLR was observed in RLS cases compared to controls (median NLR: 1.80 vs 1.72; P = 0.033). In an unadjusted logistic regression model, increased NLR was associated with RLS (OR = 1.10 per NLR unit increase [95%CI:1.01–1.20]; P = 0.032); however, the association was not significant in multivariate models adjusting for sex and age (P = 0.094) or sex, age, alcohol consumption, smoking status and BMI (P = 0.107).

Conclusion

We found no association between RLS and NLR among Danish blood donors after adjusting for sex, age, alcohol consumption, smoking status and BMI. Further studies are needed to determine whether inflammation is a risk factor for RLS.

Restless arm syndrome: a rare disease?

Restless legs syndrome (RLS) is a common neurological disorder characterised by an irresistible urge to move the lower limbs, often accompanied by unpleasant sensations in the legs, typically occurring in the evening and at night and improving with movement. Restless arms syndrome (RAS) predominantly affects the arms, while the legs are rarely affected. RAS appears to be very rare, with very few cases described to date, but the diagnosis of RAS is probably made too infrequently, especially for milder and transient forms. The patient reported here even had severe symptoms for years that could have indicated RAS. He observed an immediate improvement in all RAS-related symptoms after administration of 100 mg L-dopa +25 mg benserazide, which continues to this day. Clinicians should always be alert for RLS-like symptoms in one or both arms that worsen at rest and improve with movement, thinking of possible RAS.

Current Update on Clinically Relevant Sleep Issues in Parkinson's Disease: A Narrative Review

Sleep disturbances are among the common nonmotor symptoms in patients with Parkinson’s disease (PD). Sleep can be disrupted by nocturnal motor and nonmotor symptoms and other comorbid sleep disorders. Rapid eye movement sleep behavior disorder (RBD) causes sleep-related injury, has important clinical implications as a harbinger of PD and predicts a progressive clinical phenotype. Restless legs syndrome (RLS) and its related symptoms can impair sleep initiation. Excessive daytime sleepiness (EDS) is a refractory problem affecting patients’ daytime activities. In particular, during the COVID-19 era, special attention should be paid to monitoring sleep problems, as infection-prevention procedures for COVID-19 can affect patients’ motor symptoms, psychiatric symptoms and sleep. Therefore, screening for and managing sleep problems is important in clinical practice, and the maintenance of good sleep conditions may improve the quality of life of PD patients. This narrative review focused on the literature published in the past 10 years, providing a current update of various sleep disturbances in PD patients and their management, including RBD, RLS, EDS, sleep apnea and circadian abnormalities.

The Management of Restless Legs Syndrome: An Updated Algorithm

Restless legs syndrome (RLS) is a common disorder. The population prevalence is 1.5% to 2.7% in a subgroup of patients having more severe RLS with symptoms occurring 2 or more times a week and causing at least moderate distress. It is important for primary care physicians to be familiar with the disorder and its management. Much has changed in the management of RLS since our previous revised algorithm was published in 2013. This updated algorithm was written by members of the Scientific and Medical Advisory Board of the RLS Foundation based on scientific evidence and expert opinion. A literature search was performed using PubMed identifying all articles on RLS from 2012 to 2020. The management of RLS is considered under the following headings: General Considerations; Intermittent RLS; Chronic Persistent RLS; Refractory RLS; Special Circumstances; and Alternative, Investigative, and Potential Future Therapies. Nonpharmacologic approaches, including mental alerting activities, avoidance of substances or medications that may exacerbate RLS, and oral and intravenous iron supplementation, are outlined. The choice of an alpha₂-delta ligand as first-line therapy for chronic persistent RLS with dopamine agonists as a second-line option is explained. We discuss the available drugs, the factors determining which to use, and their adverse effects. We define refractory RLS and describe management approaches, including combination therapy and the use of high-potency opioids. Treatment of RLS in pregnancy and childhood is discussed.

Challenges in the Treatment of Restless Legs Syndrome: A Case Report

Treatment resistant restless legs syndrome (RLS) in the setting of psychiatric comorbidities can be difficult to manage. Our patient is a 69-year-old Caucasian gentleman with bipolar disorder type I, unspecified anxiety disorder, obstructive sleep apnea (OSA), and treatment-refractory RLS. At initial presentation, the patient’s prescribed medication regimen included fluoxetine 40 mg daily, gabapentin 800 mg in the morning and 3200 mg at bedtime, pramipexole 0.375 mg daily, lamotrigine 200 mg daily, trazodone 200 mg at bedtime, and temazepam 15 to 30 mg as needed for insomnia and RLS. Over the course of nearly 4 years, treatment interventions for this patient’s RLS included: cognitive behavioral therapy for insomnia, discontinuation of exacerbating medications, switching dopamine agonists, use of pregabalin and iron supplement. This report demonstrates a challenging case of RLS in the setting of psychiatric comorbidities, development of augmentation, and polypharmacy.

[Insomnia in the context of neurological diseases]

This article provides an overview of the prevalence, cause and treatment of insomnia in common neurological diseases (restless legs syndrome, stroke, multiple sclerosis, Parkinson´s disease and Alzheimer´s disease) with an additional focus on the bidirectional relationship between sleep and neurological disorders.Insomnia is prevalent, but frequently unrecognized in the context of neurological diseases. Although it is widely known that sleep has a relevant impact on quality of life in general and cerebral function in particular, sleep disorders receive little attention in the prevention and treatment of neurological diseases.

Investigation of dopaminergic signalling in Meis homeobox 1 (Meis1) deficient mice as an animal model of restless legs syndrome

Restless legs syndrome (RLS) is a common neurological disorder in which sensorimotor symptoms lead to sleep disturbances with substantial impact on life quality. RLS is caused by a combination of genetic and environmental factors, and Meis homeobox 1 (MEIS1) was identified as the main genetic risk factor. The efficacy of dopaminergic agonists, including dopamine D₂ receptor (DRD2) agonists, for treating RLS led to the hypothesis of dopaminergic impairment. However, it remains unclear whether it is directly involved in the disease aetiology and what the role of MEIS1 is considering its developmental and postnatal expression in the striatum, a critical structure in motor control. We addressed the role of MEIS1 in striatal dopaminergic signalling in Meis1^+/- mice, a valid animal model of RLS, and in Meis1^{Drd2 -/-} mice carrying a somatic null mutation of Meis1 in Drd2⁺ neurones. Motor behaviours, pharmacological exploration of DRD2 signalling, and quantitative analyses of DRD2⁺ and DRD1⁺ expressing neurones were investigated. Although Meis1^+/- mice displayed an RLS-like phenotype, including motor hyperactivity at the beginning of the rest phase, no reduction of dopaminoceptive neurones was observed in the striatum. Moreover, the null mutation of Meis1 in DRD2⁺ cells did not lead to RLS-like symptoms and dysfunction of the DRD2 pathway. These data indicate that MEIS1 does not modulate DRD2-dependent signalling in a cell-autonomous manner. Thus, the efficiency of D₂ -like agonists may reflect the involvement of other dopaminergic receptors or normalisation of motor circuit abnormalities downstream from defects caused by MEIS1 dysfunction.

Restless Legs Syndrome: Challenges to Treatment

For a long time, dopaminergic treatment (DT) was the medication for restless legs syndrome. Although DT is effective and safe over the short-term, complications develop over longer periods, including augmentation, tolerance, and impulse control disorders. Nowadays, it is recommended that first-line treatment should be alpha-2 ligands, which are more effective in the absence of previous DT. As a second-line treatment, opioids, such as oxycodone extended-release with naloxone, are approved in Europe. Brain iron should be monitored before and during treatment and corrected if necessary. Two new promising non-DTs are being developed: perampanel and dipyridamole. More research is needed.

Content Analysis of Korean Videos Regarding Restless Legs Syndrome on YouTube

OBJECTIVE

To evaluate the accuracy and quality of Korean videos associated with restless legs syndrome (RLS) on YouTube.

METHODS

A YouTube search was performed on April 1, 2020 using the term "restless legs syndrome" in the Korean language. Two reviewers coded the source, content, and demographics of the included videos. Video quality was assessed using the modified DISCERN (mDISCERN) instrument.

RESULTS

Among the 80 videos analyzed, 44 (55.0%) were reliable, and 36 (45.0%) were misleading. There was a trend toward a higher number of mean daily views in the misleading videos than in the reliable videos. Most of the misleading videos (72.2%) advocated complementary and alternative medicine as a primary treatment for RLS. Although the reliable videos had higher mDISCERN scores than the misleading videos, the overall quality of the reliable videos was low.

CONCLUSION

Many Korean videos regarding RLS on YouTube involve a risk of exposure to misinformation and are of unsatisfactory quality.

Augmentation in patients with restless legs syndrome receiving pramipexole therapy: a retrospective study in a single center from China

PURPOSE

Augmentation is a major complication of long-term pramipexole treatment of restless legs syndrome (RLS). However, there have been no studies on augmentation in Chinese patients with RLS. We therefore investigated the clinical characteristics of augmentation in RLS patients treated with pramipexole in a real-world Chinese setting.

METHODS

This study was an observational, retrospective assessment of 103 patients with RLS, who had been continuously treated with pramipexole for at least one month between January 2016 and December 2018 in a tertiary hospital in East China. Demographic data and disease and drug treatment information were collected from electronic medical records and telephone interviews to analyze the rate and clinical features of augmentation. Augmentation was confirmed by Max Planck Institute criteria. Comparisons were made between patients with and without augmentation.

RESULTS

Fifteen patients (15%) were classified as having augmentation. Compared to RLS patients without augmentation, more patients with augmentation switched from other dopaminergic drugs (P<0.05) and had a longer duration of RLS symptoms before pramipexole treatment (P<0.05). In addition, patients with augmentation had a longer duration (P<0.05) and higher dosage (P<0.05) of pramipexole than those without augmentation. Augmentation was possibly associated with pramipexole tolerance (P<0.01).

CONCLUSION

The augmentation rate of the Chinese RLS patients in our study was 15%. Augmentation may be associated with switching from other dopaminergic drugs, long disease duration before pramipexole use, the dose and duration of pramipexole, and tolerance to pramipexole.

Sleep Disorders in Parkinson Disease

Sleep disorders in Parkinson disease have attracted the attention of clinicians and researchers for decades. Recently, major advances in their clinical characterization, polysomnographic description, pathophysiologic understanding, and treatment took place. Parkinson disease encompasses the whole spectrum of sleep medicine: every category of sleep disorder can be observed in these patients. Video polysomnography frequently is indicated, sometimes followed by multiple sleep latency/maintenance of wakefulness tests. Additional studies may include actigraphy, cardiorespiratory polygraphy, and dim light melatonin assessment. Treatment needs to be specific to the underlying sleep disorder and can include medications and nondrug treatments, for example, behavioral therapy and light therapy.

Pharmacologic Treatment of Restless Legs Syndrome

Restless legs syndrome (RLS)/Willis-Ekbom disease is a neurologic disorder characterized by a strong desire to move when at rest (usually in the evening) and paraesthesia in their lower legs. The most widely used therapies for first-line treatment of RLS are dopaminergic drugs; however, their long-term use can lead to augmentation. α2δ Ligands, opioids, iron, glutamatergic drugs, adenosine, and sleep aids have been investigated as alternatives. The pathogenesis of RLS is not well understood. Despite the efficacy of dopaminergic drugs in the treatment of this disorder, unlike in Parkinson’s disease dopaminergic cell loss in the substantia nigra has not been observed in RLS. The etiology of RLS is likely complex, involving multiple neural pathways. RLS-related genes identified in genome-wide association studies can provide insight into the mechanistic basis and pathophysiology of RLS. Here we review the current treatments and knowledge of the mechanisms underlying RLS.

Consensus Guidelines on Rodent Models of Restless Legs Syndrome

Restless legs syndrome (RLS) is a chronic sensorimotor disorder diagnosed by clinical symptoms. It is challenging to translate the diagnostic self-reported features of RLS to animals. To help researchers design their experiments, a task force was convened to develop consensus guidelines for experimental readouts in RLS animal models. The RLS clinical diagnostic criteria were used as a starting point. After soliciting additional important clinical features of RLS, a consensus set of methods and outcome measures intent on capturing these features-in the absence of a face-to-face interview-was generated and subsequently prioritized by the task force. These were, in turn, translated into corresponding methods and outcome measures for research on laboratory rats and mice and used to generate the final recommendations. The task force recommended activity monitoring and polysomnography as principal tools in assessing RLS-like behavior in rodents. Data derived from these methods were determined to be the preferred surrogate measures for the urge to move, the principal defining feature of RLS. The same tools may be used to objectively demonstrate sleep-state features highly associated with RLS, such as sleep disturbance and number and periodicity of limb movements. Pharmacological challenges and dietary or other manipulations that affect iron availability are desirable to aggravate or improve RLS-like behavior and lend greater confidence that the animal model being proffered replicates key clinical features of RLS. These guidelines provide the first consensus experimental framework for researchers to use when developing new rodent models of RLS. © 2020 International Parkinson and Movement Disorder Society.

Rotigotine Transdermal Patch for Motor and Non-motor Parkinson's Disease: A Review of 12 Years' Clinical Experience

Motor and non-motor symptoms (NMS) have a substantial effect on the health-related quality of life (QoL) of patients with Parkinson's disease (PD). Transdermal therapy has emerged as a time-tested practical treatment option, and the rotigotine patch has been used worldwide as an alternative to conventional oral treatment for PD. The efficacy of rotigotine on motor aspects of PD, as well as its safety and tolerability profile, are well-established, whereas its effects on a wide range of NMS have been described and studied but are not widely appreciated. In this review, we present our overall experience with rotigotine and its tolerability and make recommendations for its use in PD and restless legs syndrome, with a specific focus on NMS, underpinned by level 1-4 evidence. We believe that the effective use of the rotigotine transdermal patch can address motor symptoms and a wide range of NMS, improving health-related QoL for patients with PD. More specifically, the positive effects of rotigotine on non-motor fluctuations are also relevant. We also discuss the additional advantages of the transdermal application of rotigotine when oral therapy cannot be used, for instance in acute medical emergencies or nil-by-mouth or pre/post-surgical scenarios. We highlight evidence to support the use of rotigotine in selected cases (in addition to general use for motor benefit) in the context of personalised medicine.

Cannabis for Restless Legs Syndrome

Restless legs syndrome (RLS) is a chronic sensorimotor disorder characterized by an urge to move the legs. This urge is often accompanied by pain or other uncomfortable and unpleasant sensations, it either occurs or worsens during rest, particularly in the evening and/or at night, and temporarily improves with activity. Affecting nearly 3% of the North American and European populations in its moderate-to-severe form, RLS has a considerable negative impact on the quality of life, and sleep and is associated with significant morbidity. Although new developments have deepened our understanding of the disorder, yet, the corresponding pathophysiologic features that underlie the sensorimotor presentation are still not fully understood. Usually, symptoms respond well to dopamine agonists (DA), anticonvulsants, or opiates, used either alone or in any combination, but still, a subset of patients remains refractory to medical therapy and serious side effects such as augmentation and impulse control disorder may occur in patients with RLS under DA. Convincing treatment alternative are lacking but recently patients' spontaneous reports of a remarkable and total remission of RLS symptoms following cannabis use has been reported. The antinociceptive effect of marijuana has been documented in many painful neurological conditions and the potential benefit of cannabis use in patients with refractory RLS should, therefore, be questioned by robust clinical trials. Here, we review basic knowledge of RLS and the putative mechanisms by which cannabis may exert its analgesic effects.

Restless Legs Syndrome: Contemporary Diagnosis and Treatment

Restless legs syndrome (RLS) is characterized by an uncomfortable urge to move the legs while at rest, relief upon movement or getting up to walk, and worsened symptom severity at night. RLS may be primary (idiopathic) or secondary to pregnancy or a variety of systemic disorders, especially iron deficiency, and chronic renal insufficiency. Genetic predisposition with a family history is common. The pathogenesis of RLS remains unclear but is likely to involve central nervous system dopaminergic dysfunction, as well as other, undefined contributing mechanisms. Evaluation begins with a thorough history and examination, and iron measures, including ferritin and transferrin saturation, should be checked at presentation and with worsened symptoms, especially when augmentation develops. Augmentation is characterized by more intense symptom severity, earlier symptom occurrence, and often, symptom spread from the legs to the arms or other body regions. Some people with RLS have adequate symptom control with non-pharmacological measures such as massage or temperate baths. First-line management options include iron-replacement therapy in those with evidence for reduced body-iron stores or, alternatively, with prescribed gabapentin or pregabalin, and dopamine agonists such as pramipexole, ropinirole, and rotigotine. Second-line therapies include intravenous iron infusion in those who are intolerant of oral iron and/or those having augmentation with intense, severe RLS symptoms, and opioids including tramadol, oxycodone, and methadone. RLS significantly impacts patients' quality of life and remains a therapeutic area sorely in need of innovation and a further pipeline of new, biologically informed therapies.

Analysis of YouTube as a source of information for restless leg syndrome

BACKGROUND

YouTube is one of the major resources for health related videos around the world.

OBJECTIVE

The aim of this study was to evaluate the quality of information available on YouTube about restless leg syndrome (RLS).

METHODS

A YouTube search was carried out on https://www.youtube.com for videos pertaining to "restless leg syndrome" by using the keyword "restless leg syndrome". The first 100 relevant videos were included in the study. The videos were accepted as "useful" if they provided scientifically correct information about any aspect of RLS. The videos containing scientifically unproven information are defined as "misleading". The overall quality of all videos was subjectively graded using the global quality scale (GQS), a 5-point Likert scale.

RESULTS

The median video length for the included videos was 3.39 (0.11-85) minutes, and the median views were 6,055 (32-2351490). The median GQS of useful videos was 3 (1-5). The median number of likes and the median number of comments of personal experience videos were significantly higher than that of the useful and misleading videos. Videos uploaded by the university hospitals frequently issued pharmacological treatment of the RLS; however, those uploaded by practitioners, individual users, and TV or social media accounts were about the non-pharmacological treatment of the RLS.

CONCLUSIONS

This study demonstrates that 77% of the videos uploaded on YouTube regarding RLS are in the useful category, whereas only 16 videos were providing misleading information. However, even videos in the useful category do not provide a full and complete description of the RLS.

Large genome-wide association study identifies three novel risk variants for restless legs syndrome

Restless legs syndrome (RLS) is a common neurological sensorimotor disorder often described as an unpleasant sensation associated with an urge to move the legs. Here we report findings from a meta-analysis of genome-wide association studies of RLS including 480,982 Caucasians (cases = 10,257) and a follow up sample of 24,977 (cases = 6,651). We confirm 19 of the 20 previously reported RLS sequence variants at 19 loci and report three novel RLS associations; rs112716420-G (OR = 1.25, P = 1.5 × 10-18), rs10068599-T (OR = 1.09, P = 6.9 × 10-10) and rs10769894-A (OR = 0.90, P = 9.4 × 10-14). At four of the 22 RLS loci, cis-eQTL analysis indicates a causal impact on gene expression. Through polygenic risk score for RLS we extended prior epidemiological findings implicating obesity, smoking and high alcohol intake as risk factors for RLS. To improve our understanding, with the purpose of seeking better treatments, more genetics studies yielding deeper insights into the disease biology are needed.