Practice guideline summary: Treatment of restless legs syndrome in adults: Report of the Guideline Development, Dissemination, and Implementation Subcommittee of the American Academy of Neurology

Clinical efficacy and safety of intravenous ferric carboxymaltose for treatment of restless legs syndrome: a multicenter, randomized, placebo-controlled clinical trial

STUDY OBJECTIVES

Iron therapy is associated with improvements in restless legs syndrome (RLS). This multicenter, randomized, double-blind study evaluated the effect of intravenous ferric carboxymaltose (FCM) on RLS.

METHODS

A total of 209 adult patients with a baseline International RLS (IRLS) score ≥ 15 were randomized (1:1) to FCM (750 mg/15 mL) or placebo on study days 0 and 5. Ongoing RLS medication was tapered starting on Day 5, with the goal of discontinuing treatment or achieving the lowest effective dose. Co-primary efficacy endpoints were changed from baseline in IRLS total score and the proportion of patients rated as much/very much improved on the Clinical Global Impression (CGI)-investigator (CGI-I) scale at day 42 in the "As-Treated" population.

RESULTS

The "As-Treated" population comprised 107 FCM and 101 placebo recipients; 88 (82.2%) and 68 (67.3%), respectively, completed the day 42 assessment. The IRLS score reduction was significantly greater with FCM versus placebo: least-squares mean (95% confidence interval [CI]) -8.0 (-9.5, -6.4) versus -4.8 (-6.4, -3.1); p = .0036. No significant difference was observed in the proportion of FCM (35.5%) and placebo (28.7%) recipients with a CGI-I response (odds ratio 1.37 [95% CI: 0.76, 2.47]; p = .2987). Fewer patients treated with FCM (32.7%) than placebo (59.4%) received RLS interventions between day 5 and study end (p = .0002). FCM was well tolerated.

CONCLUSIONS

The IRLS score improved with intravenous FCM versus placebo, although the combination of both co-primary endpoints was not met. Potential methodological problems in the study design are discussed.

Dopamine agonists in restless leg syndrome treatment and their effects on sleep parameters: A systematic review and meta-analysis

BACKGROUND

Dopamine agonists (DAs) constitute the standard therapeutic scheme for restless leg syndrome (RLS) because they have been proven to be effective. However, DAs may change sleep parameters, thus having adverse effects on patient condition. This meta-analysis clarified the effects of DAs used in RLS treatment on the sleep architecture.

METHODS

PubMed, Embase, and Cochrane Central databases were searched for randomized control trials (RCT) (up to October 2023) that discussed the effects of DAs on sleep architecture in patients with RLS. A meta-analysis employing a random-effects model was conducted. The patients were divided into subgroups according to individual DAs and treatment duration (1 day or ≥4 weeks).

RESULTS

Thirteen eligible randomized placebo-controlled trials were included in the assessment. The effects of three DAs (i.e., pramipexole, ropinirole, and rotigotine) on rapid eye movement (REM) sleep, slow-wave sleep (SWS), and sleep efficiency (SE) were analyzed. Overall, pramipexole significantly improved SE but decreased the percentage of REM sleep among treated patients. Ropinirole also enhanced SE compared with the placebo group. Rotigotine did not affect SE and REM sleep. Subgroup analysis found that pramipexole used for 1 day and ≥4 weeks significantly diminished the percentage of REM sleep. Ropinirole used for 1 day showed similar REM sleep patterns. Finally, none of the three DAs affected SWS.

CONCLUSIONS

This meta-analysis demonstrated that DAs significantly affect sleep parameters.

Compromised Dynamic Cerebral Autoregulation in Patients with Restless Legs Syndrome

Background

Restless legs syndrome (RLS) is a prevalent sensorimotor nervous system disorder in patients accompanied with insomnia, blood pressure fluctuation, and sympathetic dysfunction. These symptoms may disrupt cerebral hemodynamics. Dynamic cerebral autoregulation (dCA) describes the temporary response of cerebrovascular system to abrupt fluctuations in blood pressure, which keep cerebral blood flow stable and serve as a marker of cerebrovascular system ability.

Objective

This research aimed to assess dCA in RLS patients.

Methods

In this study, RLS patients were recruited and subsequently classified into four groups (mild, moderate, severe, and very severe) based on the International RLS Rating Scale (IRLS). Healthy controls matched for age and sex were enrolled. All participants were evaluated dCA by assessing phase difference (PD). A portion of patients with RLS was reassessed for dCA after one month of medication therapy (pramipexole [0.125 mg/day] and gabapentin [300 mg/day]).

Results

There were altogether 120 patients with RLS and 30 controls completed the polysomnography and dCA assessment. PD was lower in the moderate, severe, and very severe RLS groups than that in the controls and mild RLS groups. Periodic limb movement index (PLMI), arousal index, and IRLS all showed a linear correlation with PD in RLS patients. Additionally, PD increased in RLS patients after therapy.

Conclusion

The dCA was compromised in moderate, severe, and very severe RLS patients and was negatively correlated with the IRLS, arousal index, and PLMI. After 1 month of therapy, dCA improved in RLS patients.

Preoperative pregabalin prevents succinylcholine-induced fasciculation and myalgia: A meta-analysis of randomized trials

Succinylcholine is the gold standard neuromuscular blocker for rapid sequence induction; however, its use is associated with fasciculation and myalgia. We performed a systematic review and meta-analysis of randomized controlled clinical trials comparing gabapentinoids versus placebo for the prevention of fasciculations and succinylcholine-induced myalgias. Six randomized clinical studies were included with a total of 481 patients - 241 in the intervention group and 240 in the placebo group. Gabapentinoids reduced the incidence of succinylcholine-induced myalgia (RR=0.69, 95% CI 0.56-0.84, P<.001), which remained statistically significant for pregabalin (RR=0.71, 95% CI 0.54-0.93, P=.013) and gabapentin (RR=0.61, 95% CI 0.45-0.82, P=.001) separately. There was no difference in fasciculations between the groups (RR=0.92, 95% CI 0.82-1.03, P=.148). Preoperative use of gabapentinoids is associated with lower incidence of succinylcholine-induced myalgias within the first 24h of surgery.

A comprehensive update on the ADMET considerations for α2δ calcium channel ligand medications for treating restless legs syndrome

INTRODUCTION

Restless legs syndrome/Willis-Ekbom disease (RLS/WED) is a sleep-related sensory-motor disorder associated with poor sleep quality and impaired daily functioning. In patients affected by chronic RLS/WED, a pharmacological therapy is recommended. International guidelines suggest to start the treatment with a α2δ calcium channel ligand in most cases, unless contraindicated.

AREAS COVERED

The present review is based on an extensive Internet and PubMed search from 1986 to 2024. Our purpose is to describe the absorption, distribution, metabolism, and toxicology (ADMET) of the α2δ ligands, with common consideration for the therapeutic class, specificities of different compounds, efficacy, and safety in relation to other treatment options.

EXPERT OPINION

α2δ ligands are quite similar in their ADMET profiles, sharing most of the pharmacokinetics and potential adverse effects. However, we highlight the linear kinetic of gabapentin enacarbil and pregabalin, differently from gabapentin. α2δ ligands are safe and effective for the treatment of RLS/WED. Additional benefits can be obtained in comorbid insomnia, chronic pain syndromes, history of impulse control disorder, and comorbid anxiety. The use of α2δ ligands is associated with poor risk of augmentation. We still need new long-term safe and effective treatments, which could be developed along with our knowledge of RLS/WED pathophysiology.

Expert opinion on diagnosis and management of epilepsy-associated comorbidities

Apart from seizure freedom, the presence of comorbidities related to neurological, cardiovascular, or psychiatric disorders is the largest determinant of a reduced health-related quality of life in people with epilepsy (PwE). However, comorbidities are often underrecognized and undertreated, and clinical management of comorbid conditions can be challenging. The focus of a comprehensive treatment regimen should maximize seizure control while optimizing clinical management of treatable comorbidities to improve a person's quality of life and overall health. A panel of four European epileptologists with expertise in their respective fields of epilepsy-related comorbidities combined the latest available scientific evidence with clinical expertise and collaborated to provide consensus practical advice to improve the identification and management of comorbidities in PwE. This review provides a critical evaluation for the diagnosis and management of sleep-wake disorders, cardiovascular diseases, cognitive dysfunction, and depression in PwE. Whenever possible, clinical data have been provided. The PubMed database was the main search source for the literature review. The deleterious pathophysiological processes underlying neurological, cardiovascular, or psychiatric comorbidities in PwE interact with the processes responsible for generating seizures to increase cerebral and physiological dysfunction. This can increase the likelihood of developing drug-resistant epilepsy; therefore, early identification of comorbidities and intervention is imperative. The practical evidence-based advice presented in this article may help clinical neurologists and other specialist physicians responsible for the care and management of PwE.

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.

Incident mental health episodes after initiation of gabapentinoids vs. dopamine agonists for early-onset idiopathic restless legs syndrome

Limited long-term safety information exists for gabapentinoid treatment of idiopathic restless legs syndrome (RLS). We estimated incident mental health-related emergency department visits and hospitalizations with a primary mental health diagnosis (primary outcome) among early-onset idiopathic RLS patients following first-line treatment initiation and examined outcome risk with gabapentinoids compared with dopamine agonists (DAs). A retrospective cohort study was conducted using administrative claims data from 2012 to 2019. Adults with early-onset (18-44 years) idiopathic RLS initiating either gabapentinoids or DAs within 60 days of new diagnosis were followed up to two years. Incidence rates were calculated and a log-binomial regression model with propensity score weighting estimated relative risk of the outcome and of substance use disorders (SUDs) as a secondary analysis with gabapentinoids. Among a cohort of 6,672 patients, 4,986 (74.7%) initiated DAs and 1,686 (25.3%) gabapentinoids. Incidence of the primary outcome (49.8 [95% CI 40.8-69.3] per 1,000 person-years) and SUDs (49.5 [95% CI 40.6-59.9] per 1,000 person-years) were higher in the gabapentinoid group compared with the DA group. A statistically significant risk of mental health diagnoses with gabapentinoids was not detected, but SUD risk was significant after covariate adjustment. High-risk mental health comorbidities (i.e., SUDs) should be considered when initiating RLS treatments.

Exploring the causes of augmentation in restless legs syndrome

Long-term drug treatment for Restless Legs Syndrome (RLS) patients can frequently result in augmentation, which is the deterioration of symptoms with an increased drug dose. The cause of augmentation, especially derived from dopamine therapy, remains elusive. Here, we review recent research and clinical progress on the possible mechanism underlying RLS augmentation. Dysfunction of the dopamine system highly possibly plays a role in the development of RLS augmentation, as dopamine agonists improve desensitization of dopamine receptors, disturb receptor interactions within or outside the dopamine receptor family, and interfere with the natural regulation of dopamine synthesis and release in the neural system. Iron deficiency is also indicated to contribute to RLS augmentation, as low iron levels can affect the function of the dopamine system. Furthermore, genetic risk factors, such as variations in the BTBD9 and MEIS1 genes, have been linked to an increased risk of RLS initiation and augmentation. Additionally, circadian rhythm, which controls the sleep-wake cycle, may also contribute to the worsening of RLS symptoms and the development of augmentation. Recently, Vitamin D deficiency has been suggested to be involved in RLS augmentation. Based on these findings, we propose that the progressive reduction of selective receptors, influenced by various pathological factors, reverses the overcompensation of the dopamine intensity promoted by short-term, low-dose dopaminergic therapy in the development of augmentation. More research is needed to uncover a deeper understanding of the mechanisms underlying the RLS symptom and to develop effective RLS augmentation treatments.

Change of iron content in brain regions after intravenous iron therapy in restless legs syndrome: quantitative susceptibility mapping study

STUDY OBJECTIVES

The pathomechanism of restless legs syndrome (RLS) is related to brain iron deficiency and iron therapy is effective for RLS; however, the effect of iron therapy on human brain iron state has never been studied with magnetic resonance imaging. This study aimed to investigate the change of brain iron concentrations in patients with RLS after intravenous iron therapy using quantitative susceptibility mapping (QSM).

METHODS

We enrolled 31 RLS patients and 20 healthy controls. All participants underwent initial baseline (t0) assessment using brain magnetic resonance imaging, serum iron status, and sleep questionnaires including international RLS Study Group rating scale (IRLS). RLS patients underwent follow-up tests at 6 and 24 weeks (t1 and t2) after receiving 1000 mg ferric carboxymaltose. Iron content of region-of-interest on QSM images was measured for 13 neural substrates using the fixed-shaped method.

RESULTS

RLS symptoms evaluated using IRLS were significantly improved after iron treatment (t0: 29.7 ± 6.5, t1: 19.5 ± 8.5, t2: 21.3 ± 10.1; p < .001). There was no significant difference in susceptibility values between the controls and RLS patients at t0. In the caudate nucleus, putamen, and pulvinar thalamus of RLS patients, the QSM values differed significantly for three timepoints (p = .035, .048, and .032, respectively). The post-hoc analysis revealed that the QSM values increased at t1 in the caudate nucleus (66.8 ± 18.0 vs 76.4 ± 16.6, p = .037) and decreased from t1 to t2 in the putamen (69.4 ± 16.3 vs 62.5 ± 13.6, p = .025). Changes in the QSM values for the pulvinar and caudate nuclei at t1 were positively and negatively correlated with symptomatic improvement, respectively (r = 0.361 and -0.466, respectively).

CONCLUSIONS

Intravenous iron treatment results in changes in brain iron content which correlate to reductions in RLS severity. This suggests a connection between symptom improvement and the associated specific brain regions constituting the sensorimotor network.

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.

Validation of Administrative Health Data Algorithms for Identifying Persons with Parkinson's Disease and the 10-Year Prevalence Trend in Bologna, Italy

INTRODUCTION

Health administrative databases are widely used for the estimation of the prevalence of Parkinson's disease (PD). Few in general, and none used in Italy, have been validated by testing their diagnostic accuracy. The primary objective was to validate two algorithms for the identification of persons with PD using clinical diagnosis as the reference standard on an Italian sample of people with PD. The second objective was to estimate 10-year trends in PD prevalence in the Bologna Local Health Trust from 2010 to 2019.

METHODS

Two algorithms (index tests) applied to health administrative databases (hospital discharge, drug prescriptions, exemptions for medical costs) were validated against clinical diagnosis of PD by an expert neurologist (reference standard) in a cohort of consecutive outpatients. Sensitivity and specificity with relative 95% confidence intervals (CIs) were calculated. The prevalence of PD in a specific year was estimated as the ratio between the number of subjects fulfilling any criteria of the algorithm with better diagnostic accuracy and the total population in the same year (×1,000), stratified by age, sex, and district of residence.

RESULTS

The two algorithms showed high accuracy for identifying patients with PD: one with greater sensitivity of 94.2% (CI: 88.4-97.6) and the other with greater specificity of 98.1% (CI: 97.7-98.5). For the estimation of prevalence, we chose the most specific algorithm with the fewest total number of misclassified cases. We identified 3,798 people with PD as of December 31, 2019, corresponding to a prevalence of 4.3 per 1,000 inhabitants (CI: 4.2-4.4). Prevalence was higher in males (4.7, CI: 4.5-5.0) than females (3.8, CI: 3.7-4.0) and increased with age. The crude prevalence over time was slightly elevated as it followed a progressive aging of the population. When stratifying the prevalence for age groups, we did not observe a trend except in the 45-64 year category where we observed an increasing trend over time.

CONCLUSION

Algorithms based on administrative data are accurate when detecting people with PD in the Italian public health system. In a large northern Italian population, increased prevalence of about 10% was observed in the decade 2010-2019 and is explained by increased life expectancy. These data may be useful in planning the allocation of health care resources for people with PD.

Inflammation, Dopaminergic Brain and Bilirubin

Dopamine is a well-known neurotransmitter due to its involvement in Parkinson's disease (PD). Dopamine is not only involved in PD but also controls multiple mental and physical activities, such as the pleasure of food, friends and loved ones, music, art, mood, cognition, motivation, fear, affective disorders, addiction, attention deficit disorder, depression, and schizophrenia. Dopaminergic neurons (DOPAn) are susceptible to stressors, and inflammation is a recognized risk for neuronal malfunctioning and cell death in major neurodegenerative diseases. Less is known for non-neurodegenerative conditions. Among the endogenous defenses, bilirubin, a heme metabolite, has been shown to possess important anti-inflammatory activity and, most importantly, to prevent DOPAn demise in an ex vivo model of PD by acting on the tumor necrosis factor-alpha (TNFα). This review summarizes the evidence linking DOPAn, inflammation (when possible, specifically TNFα), and bilirubin as an anti-inflammatory in order to understand what is known, the gaps that need filling, and the hypotheses of anti-inflammatory strategies to preserve dopamine homeostasis with bilirubin included.

Assessment of Sleep Disturbances on Mental Health in Patients with Restless Legs Syndrome

Background and Objective

In our study, we aimed to evaluate the sleep disturbances of patients diagnosed with restless legs syndrome (RLS) regarding their mental health according to the severity of the disease.

Materials and Methods

The study included 166 patients diagnosed with RLS and 161 healthy controls in the same age interval as patients. Sleep disturbances of patients were defined with the "personal information form" (PIF) prepared by the researchers, while the mental health status of patients was defined with the "Brief Symptom Inventory" (BSI).

Results

All RLS patients had an increase in BSI subscale points, with a positive correlation to disease severity, and subscale points were significantly higher than the control group (p < 0.05). Those with the "frequent waking" problem had higher BSI subscale points compared to those without the problem (p<0.01 or 0.001). Those with "waking with respiratory distress," "daytime sleepiness," "very early waking," and "sleep disorder" problems had statistically significantly high BSI subscale points for all subscales, apart from hostility, compared to those without these problems (p<0.01 or 0.001).

Conclusion

It is considered that assessment of sleep disturbances causing disrupted quality of life and mood disorders is beneficial for the treatment of patients with RLS. Our study data appears to be related to the result that sleep disturbances and mental health disruptions might be associated with the disease severity among RLS patients.

Iron status in women with infertility and controls: a case-control study

Background

Iron deficiency is a common problem in subfertile women. The influence of iron status on unexplained infertility is unknown.

Methods

In a case-control study, 36 women with unexplained infertility and 36 healthy non-infertile controls were included. Parameters of iron status including serum ferritin and a serum ferritin <30 µg/dL served as main outcome parameters.

Results

Women with unexplained infertility demonstrated a lower transferrin saturation (median 17.3%, IQR 12.7-25.2 versus 23.9%, IQR 15.4-31.6; p= 0.034) and a lower mean corpuscular hemoglobin concentration (median 33.6 g/dL, IQR 33.0-34.1 versus 34.1 g/dL, IQR 33.2-34.7; p= 0.012). Despite the fact that there was no statistically significant difference in median ferritin levels (p= 0.570), women with unexplained infertility had ferritin levels <30µg/L more often (33.3%) than controls (11.1%; p= 0.023). In a multivariate model, unexplained infertility and abnormal thyroid antibodies were associated with ferritin <30µg/L (OR 4.906, 95%CI: 1.181-20.388; p= 0.029 and OR 13.099; 2.382-72.044; p= 0.029, respectively).

Conclusion

Ferritin levels <30µg/L were associated with unexplained infertility and might be screened in the future. Further studies with a focus on iron deficiency and iron treatment on women with unexplained infertility are warranted.

Effectiveness of low-dose iron treatment in non-anaemic iron-deficient women: a prospective open-label single-arm trial

BACKGROUND

Iron deficiency without anaemia is highly prevalent and is particularly associated with fatigue, cognitive impairment, or poor physical endurance. Standard oral iron therapy often results in intestinal irritation with associated side effects and premature discontinuation of therapy, therefore, optimal oral iron therapy with sufficient iron absorption and minimal side effects is desirable.

METHODS

Thirty-six iron-deficient non-anaemic premenopausal women (serum ferritin ≤30 ng/ml, haemoglobin ≥117 g/l) with normal body mass index (BMI) and no hypermenorrhea received 6 mg of elemental oral iron (corresponding to 18.6 mg ferrous sulphate) twice daily for 8 weeks.

RESULTS

Participants treated with low-dose iron had an average age of 28 years and a BMI of 21 kg/m2. Their serum ferritin and haemoglobin increased significantly from 18 ng/ml to 33 ng/ml (p <0.001) and from 135 g/l to 138 g/l (p = 0.014), respectively. Systolic blood pressure increased from 114 mmHg to 120 mmHg (p = 0.003). Self-reported health status improved after 8 weeks (p <0.001) and only one woman reported gastrointestinal side effects (3%).

CONCLUSION

This prospective open-label single-arm trial shows that oral iron treatment of 6 mg of elemental iron twice daily over 8 weeks is effective in iron-deficient non-anaemic women. Due to the negligible side effects, low-dose iron treatment is a valuable therapeutic option for iron-deficient non-anaemic women with normal BMI and menstruation. Further placebo-controlled studies with a larger number of participants are needed to confirm these results.

CLINICALTRIALS

gov NCT04636060.

Cannabis and sleep disorders: not ready for prime time? A qualitative scoping review

STUDY OBJECTIVES

To perform a qualitative scoping literature review for studies involving the effects of cannabis on sleep and sleep disorders.

METHODS

Two electronic databases, MEDLINE and EMBASE, searched for comprehensive published abstracted studies that involved human participants. Inclusion criteria were article of any type, published in English, a target population of cannabis users, and reported data on cannabis effect on sleep and sleep disorders. The Joanna Briggs Institute's (JBI) approach was elected as the methodology framework guidance in the scoping review process.

RESULTS

A total of 40 unique publications were found. The majority (82.5%) were from the Americas with 60% published in the last decade. Of the 40 studies, only 25% were randomized control trials, and the sleep outcome measurements were similar and comparable in only 20%. Cannabis users studied were reported either 73% frequent users or 27% sporadic users. The utilization of cannabis showed improved sleep (21%), worse sleep (48%), mixed results (14%), or no impact at all (17%) in the studies published in the last 5 decades.

CONCLUSIONS

Our findings summarize the lack of robust evidence to support the use of cannabis for sleep disorders. The varied cannabis user-related characteristics may account for the inconsistent results identified. Further studies assessing cannabis and sleep are needed to discern what works in what context, how it works, and for whom.

CITATION

Amaral C, Carvalho C, Scaranelo A, Chapman K, Chatkin J, Ferreira I. Cannabis and sleep disorders: not ready for prime time? A qualitative scoping review. J Clin Sleep Med. 2023;19(5):975-990.

Clinical Evaluation of Sleep Disorders in Parkinson’s Disease

The paradigm of the framing of Parkinson’s disease (PD) has undergone significant revision in recent years, making this neurodegenerative disease a multi-behavioral disorder rather than a purely motor disease. PD affects not only the “classic” substantia nigra at the subthalamic nuclei level but also the nerve nuclei, which are responsible for sleep regulation. Sleep disturbances are the clinical manifestations of Parkinson’s disease that most negatively affect the quality of life of patients and their caregivers. First-choice treatments for Parkinson’s disease determine amazing effects on improving motor functions. However, it is still little known whether they can affect the quantity and quality of sleep in these patients. In this perspective article, we will analyze the treatments available for this specific clinical setting, hypothesizing a therapeutic approach in relation to neurodegenerative disease state.

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.

Gabapentinoid Prescribing Practices at a Large Academic Medical Center

Objective

To evaluate indications for gabapentinoid prescription at an academic medical center.

Patients and Methods

We retrospectively reviewed patients aged 18 years or older who were prescribed gabapentinoids (gabapentin or pregabalin) during the 2019 calendar year at an academic medical center in the US Midwest. Patient demographic characteristics, indications for gabapentinoid prescription, and prescribing clinician specialities were abstracted from a random sample, and the findings were extrapolated to the overall cohort.

Results

A total of 6205 prescriptions for gabapentinoids were initially identified. In the random sample of prescriptions (n=721), 89.5% were for gabapentin and 10.5% were for pregabalin. More women than men were prescribed gabapentinoids, and the mean ± SD patient age was 58.6±16.9 years. The top 5 indications for gabapentinoid prescriptions were neuropathic pain, musculoskeletal pain, restless legs syndrome, anxiety, and headache. A majority (66.7%) of prescriptions had substantial-to-modest evidence, but 29.0% of prescriptions had conflicting or insufficient evidence.

Conclusion

To our knowledge, this study is one of the first to manually review clinical notes from multiple clinical specialities to ascertain indications for gabapentinoid prescriptions. Although most prescriptions had modest evidence to support their use, a high percentage of gabapentinoid prescriptions were issued for indications not supported by robust evidence. This suggests that prescribers are gravitating toward gabapentinoid use for reasons that are currently not fully understood. Clinician intent for off-label gabapentinoid prescriptions at the point of care should be further studied to understand the factors that lead to these clinical decisions.

Circadian rhythm in restless legs syndrome

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

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.

Effects of acupuncture on sensory symptoms and motor signs in patients with restless legs syndrome: A crossover randomized controlled trial

BACKGROUND

Rapid effects of acupoint injection (acuinjection) at 4 acupoints (4P) (ST36, GB41, SP6, and BL60) on legs presenting sensory symptoms and motor signs in restless legs syndrome (RLS) were first described in a case report. This study aimed to confirm the beneficial effects of acuinjection.

METHODS

A randomized, controlled, single-blinded, prospective crossover study was conducted during 2018 to 2021. Adult volunteers (age ≥ 20 years) with RLS symptoms for > 2 weeks were included. Eight adults were enrolled and randomized to receive acuinjection (Verum group) or sham injection (Sham group). The effects of acuinjection on discomfort and periodic leg movement (PLM) were evaluated using the suggested immobilization test in a crossover design. The acupoint used was 4P, and normal saline solution (0.1-0.25 mL) was injected in both groups. Leg discomfort was measured using the visual analog scale (VAS), and PLM was measured using an electromyogram. To compare the VAS scores between the groups, repeated measures analysis of variance was used, and the Student t test was used to assess the mean discomfort score (MLDS: average of the 6 VAS scores) and PLM index (PLMI) (defined as the degree of PLM/hour).

RESULTS

A significant difference in the VAS score was observed; however, no significant difference was noted in the PLMI between the groups. The MLDS was significantly lower in the Verum group than in the Sham group.

CONCLUSION

Acuinjection at 4P remarkably inhibited leg discomfort in patients with RLS. Despite the drastic PLM suppression in 1 patient by acuinjection, a statistically significant inhibition of PLM was not confirmed. The results of our study can be applied easily and safely in clinical situations where it is necessary to temporarily reduce or eliminate RLS symptoms.

Restless arms syndrome with oral olanzapine: case based review

Background

Restless arms syndrome (RAS) is a specific variant of restless legs syndrome (RLS). RAS is characterised by an uncomfortable, painful, burning or uneasy sensation confined to the arm.

Case presentation

We report a case of RAS with oral olanzapine, which improved with medication reduction. In addition, all reported cases of RAS were reviewed to explore the underlying mechanisms, diagnosis and treatment for psychiatric drug-induced RAS. The literature review and new case suggest that iron deficiency may be a predisposing factor for RAS. Psychiatric medications are closely associated with RAS, especially olanzapine, quetiapine, and mirtazapine. Discontinuation is the recommended treatment for psychotropic drug-induced RAS, while α2δ calcium channel ligand drugs and benzodiazepines may be considered.

Conclusion

In conclusion, psychiatrists should be alert to the possibility of RAS when administering psychiatric medications for the first time to psychiatric patients with iron deficiency.

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

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

Restless legs syndrome after acute ıschemic stroke and ıts relation to lesion location

Purpose

We aimed to investigate the prevalence, clinical profiles and lesion location of Restless Legs Syndrome (RLS) developed after ischemic stroke.

Methods

This study prospectively included 244 patients with acute cerebral infarction. All patients were evaluated for RLS, and those who met all of the essential diagnostic criteria of the International RLS Study Group were diagnosed with RLS. The evaluation of lesion location was performed by magnetic resonance imaging. International Restless Legs Syndrome Rating Scale was performed 1 week, 1 month, and 3 months after the index stroke to determine the symptom severity of the patients and to observe the exacerbation or regression in follow-up.

Results

A total of 14 patients (5.7%) had post-stroke RLS (psRLS). The psRLS group consisted mostly of males (9 males, 5 females). Among the patients with psRLS, 12 had a subcortical stroke (9.2%, 130 patients) whereas only 2 had a cortical stroke (1.8%, 114 patients) (p = 0.01). The subcortical lesion locations in the psRLS group were the pons, basal ganglia and/or corona radiata, thalamus, and cerebellum in order of decreasing frequency. Five patients had symptoms in both legs, and 9 patients had symptoms in unilateral legs (7 contralateral, 2 ipsilateral to the lesion). At follow-up, the symptoms of 6 patients resolved completely without medication, 5 patients responded well to pramipexole and 1 patient responded poorly. Only 2 patients who refused to take medication had worsened symptoms.

Conclusion

The subcortical ischemic lesions are associated with psRLS. Pons, basal ganglia and corona radiata are the structures more likely to cause RLS.

Study on restless leg syndrome and its relationship with quality of sleep among the general population of Mangalore, India

Background

Restless leg syndrome (RLS) is a common neurological morbidity. It is, however, a frequently underdiagnosed medical condition. This study was hence done to assess the occurrence and severity of RLS among participants and to study its determinants and its association with quality of sleep. This was a cross-sectional study conducted among the general population of Mangalore in July 2021. Data were collected using a Google Form. The International Restless Legs Syndrome Study Group Rating Scale was used to diagnose RLS and its severity. The Pittsburgh Sleep Quality Index (PSQI) was used to assess sleep quality.

Results

The prevalence of RLS among the 202 participants was 24(11.9%). Among them, 5 were already diagnosed with RLS. Their mean age at onset was 40.4 ± 25.3 years. Among the rest 197 participants, 19(9.6%) were newly diagnosed with RLS. The severity of RLS was mild, moderate and severe among 7(36.8%), 9(47.4%) and 3(15.8%) participants, respectively. Five (26.3%) of the 19 newly diagnosed participants were identified as RLS sufferers. In multivariable analysis, the presence of diabetes mellitus and family history of RLS were  associated with the presence of RLS among the participants. The mean Global PSQI value was 5.0 ± 3.1. Sleep latency was prolonged (p = 0.001), and sleep disturbances (p = 0.01) were higher among participants newly diagnosed with RLS (n = 19) compared to those without RLS (n = 178). Subjective sleep quality was poor (p = 0.038), and sleep disturbances (p = 0.016) were more among participants with severe degree RLS.

Conclusions

The prevalence of RLS in the present study was higher than that reported in previous Indian studies. Unpleasant sensations in RLS affected sleep initiation and maintenance among the affected. A multi-disciplinary approach is required to control its determinants and address other sleep-related problems among the RLS affected population.

Pharmacologic and Nonpharmacologic Treatment of Restless Legs Syndrome

Restless legs syndrome (RLS) is a sleep-related disorder defined by an urgency to move the legs, usually combined with uncomfortable or unpleasant sensations, which occurs or worsens during rest, usually in the evening or at night, and disappears with the movement of the legs. RLS can be classified as idiopathic or primary, and secondary to comorbid conditions (eg, renal disease, polyneuropathy). The pathophysiology of RLS is still unclear. This article provides an updated practical guide for the treatment of primary RLS in adults.

Restless Legs Syndrome and the Use of Antipsychotic Medication: An Updated Literature Review

Restless legs syndrome or Willis-Ekbom disease (RLS/WED) is a sleep-related movement disorder characterized by an urge to move the legs. This impulse is usually accompanied by an uncomfortable and unpleasant sensation in the legs, which worsens at night and during periods of inactivity and is relieved by movement. Several studies in the literature reported the association between RLS and different antipsychotic medications. with Olanzapine, Quetiapine, and Clozapine identified as the most common causes. The literature suggests that the development of RLS in antipsychotic users may be attributed to the inhibition of dopaminergic neurotransmission or the impact of antipsychotics on iron metabolism. Diagnosing antipsychotic-induced RLS remains a substantial challenge in clinical practice, with challenges in the management of this condition also being widely reported in the current literature. In this article, we will review the evidence suggesting the association between RLS and the use of antipsychotic medications, differentiate between RLS and other movement disorders, and give a brief review of the pathophysiology, diagnosis, and management of RLS and its challenges among psychotic patients.

Repetitive Transcranial Magnetic Stimulation of the Primary Motor Cortex beyond Motor Rehabilitation: A Review of the Current Evidence

Transcranial magnetic stimulation (TMS) has emerged as a novel technique to stimulate the human brain through the scalp. Over the years, identifying the optimal brain region and stimulation parameters has been a subject of debate in the literature on therapeutic uses of repetitive TMS (rTMS). Nevertheless, the primary motor cortex (M1) has been a conventional target for rTMS to treat motor symptoms, such as hemiplegia and spasticity, as it controls the voluntary movement of the body. However, with an expanding knowledge base of the M1 cortical and subcortical connections, M1-rTMS has shown a therapeutic efficacy that goes beyond the conventional motor rehabilitation to involve pain, headache, fatigue, dysphagia, speech and voice impairments, sleep disorders, cognitive dysfunction, disorders of consciousness, anxiety, depression, and bladder dysfunction. In this review, we summarize the latest evidence on using M1-rTMS to treat non-motor symptoms of diverse etiologies and discuss the potential mechanistic rationale behind the management of each of these symptoms.

Chronic testicular pain cured by low-dose pramipexole: is there an association with restless legs syndrome?

Restless legs syndrome (RLS) is characterized by an urge to move the legs, predominantly at night. About one quarter of the patients with RLS report painful symptoms in the legs. In this case report, the patient presented at the sleep clinic with a chief complaint of insomnia and the classical symptoms of RLS. He also mentioned a chronic testicular pain (CTP). For over a year, the patient had undergone urologic investigation and empiric treatments, with only mild improvement of the testicular pain. After 3 months of therapy with pramipexole, the RLS symptoms and the CTP were no longer present. Finding an etiology for CTP can be challenging and many cases are diagnosed as idiopathic. RLS may be a forgotten and unidentified etiology for CTP in typical urological care. Considering the high prevalence of RLS and CTP, it is relevant to clarify the possible association.

CITATION

Tedesco Silva LM, Lenz MCS, Martinez D. Chronic testicular pain cured by low-dose pramipexole: Is there an association with restless legs syndrome? J Clin Sleep Med. 2022;18(5):1467-1469.

Short course of low-dose pregabalin is effective for the treatment of restless leg syndrome in patients with cirrhosis: A pilot study

BACKGROUND AND AIM

Restless leg syndrome (RLS) is common in patients with cirrhosis, but its treatment in such patients remains unclear. This pilot study assessed the clinical effectiveness of intravenous iron and a 6-week course of low-dose (75 mg/day) pregabalin for the treatment of RLS in patients with cirrhosis.

METHODS

It was a prospective, interventional study that included adult patients with cirrhosis and RLS. The participants underwent serum ferritin measurement. Patients with low serum ferritin (< 75 μg/dL) were treated with intravenous iron. Those with normal ferritin levels and those with low levels whose RLS symptoms failed to respond to iron replacement were treated with oral pregabalin, initially 75 mg/day for 6 weeks, followed by 150 mg/day for 6 weeks if there was no response. Recurrence of symptoms was assessed at 6-12 weeks after stopping pregabalin.

RESULTS

Of the 50 patients (male patients 52%; median age 48 [interquartile range: 21-65] years; median Child-Pugh-Turcotte score 8 [5-13] and median Model for End-Stage Liver disease score 17 [12-20]) studied, 29 (58%) had low ferritin; of them, 14 (48%) responded to intravenous iron alone. Eleven of 15 (38%) patients with low ferritin and nonresponse to iron, and 16 of 21 (76%) with normal ferritin levels had a response with low-dose pregabalin. Of the nine nonresponders who received 150 mg/day of pregabalin, four had to discontinue it because of adverse effects.

CONCLUSION

A short course of low-dose (75 mg/day) pregabalin was effective (82%) in alleviating RLS in patients with cirrhosis. (CTRI/2019/02/017642).

Restless Legs Syndrome in X-linked adrenoleukodystrophy

OBJECTIVE/BACKGROUND

X-linked adrenoleukodystrophy (ALD) is a neurodegenerative disease that causes progressive gait and balance problems. Leg discomfort, sleep disturbances, and pain contribute to daily disability. We sought to investigate the prevalence and severity of Restless Legs Syndrome (RLS) in patients with ALD.

PATIENTS/METHODS

We administered questionnaires and conducted diagnostic telephone interviews to assess RLS severity. We retrospectively extracted data from neurological examinations, functional gait measures, and laboratory assessments.

RESULTS AND CONCLUSIONS

Thirty-two adults with ALD (21 female, 11 male) were recruited to participate. Thirteen patients (40.6%) had RLS (10/21 females and 3/11 males). The median age of RLS onset was 35 years [IQR = 22-54]. Patients with RLS had more signs and symptoms related to myelopathy, but not the brain demyelination seen in ALD. This pilot study suggests a high prevalence of RLS in adults with ALD, which may contribute to sleep problems and impair quality of life.

Association of Periodic Limb Movements with Medication Classes: A Retrospective Cohort Study

OBJECTIVE

To investigate the association between various medication classes and the periodic limb movement index (PLMI) in a clinical cohort of adults who completed in-laboratory polysomnography.

METHODS

A single, diagnostic, overnight, in-laboratory polysomnogram was completed for 3,488 patients consecutively referred from 2010-2015 to determine the PLMI. Medication use and medical comorbidities were collected through patient questionnaires. Associations between medication classes and the PLMI were ascertained using multivariable ordinal logistic regression models.

RESULTS

The median age of the cohort was 56.0 years (48.2% male). After adjusting for age, sex, body mass index, relevant comorbidities, and sleep parameters, the use of selective serotonin reuptake inhibitors (SSRIs) (OR = 1.52) and serotonin-norepinephrine reuptake inhibitors (SNRIs) (OR = 1.99) were associated with an increased PLMI. Conversely, gabapentinoids (OR = 0.71), stimulants (OR = 0.52), benzodiazepines (OR = 0.79), and dopamine agonists (OR = 0.38) were associated with a decreased PLMI. A non-statistically significant trend for a decreased PLMI with neuroleptic use was observed. No significant associations were found between the PLMI and the use of antihypertensives, statins, tricyclic antidepressants, bupropion, anticoagulants, antiplatelets, modafinil, and antihistamines.

CONCLUSION

The use of SSRIs and SNRIs was associated with an elevated PLMI while the use of gabapentinoids, stimulants, benzodiazepines, and dopamine agonists was associated with a decreased PLMI. These results can assist physicians in managing PLMs and invite further research into the relationship between PLMs and medications with the modulating effects of dose, formulation type, and time of administration.

CLASSIFICATION OF EVIDENCE

This study provides Class II evidence that SSRIs and SNRIs are associated with an elevated PLMI while gabapentinoids, stimulants, benzodiazepines, and dopamine agonists are associated with a decreased PLMI.

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.

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.

Restless legs syndrome

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

A network meta-analysis of the effectiveness and safety of drugs for restless legs syndrome in dialysis patients

OBJECTIVE

To evaluate the efficacy and safety of nine pharmacological interventions for restless legs syndrome (RLS) in dialysis patients.

METHODS

An electronic database was used to retrieve eligible trials from PubMed, Cochrane, Embase, and Web of Science. Stata 14.2 software was used to perform network meta-analysis. The primary measure was the RLS score, and the secondary measure was used to evaluate the side effects of the drug. The surface under the cumulative ranking curve method was used to rank the merits of intervention measures. A comparison of the two interventions is shown on a league table.

RESULTS

Finally, nine randomized controlled trials (RCTs) with a total of 377 participants were included. From the results of the network meta-analysis, all treatments ranked higher than placebo in terms of improving clinical symptoms, but only vitamin C (standardized mean difference [SMD] = -1.47 95% confidence interval [CI] -2.89, -0.05) showed significant differences compared with placebo. In terms of safety, there were no serious adverse reactions to any of the treatments compared to placebo.

CONCLUSION

Currently, existing evidence suggests that vitamin C may be the most ideal drug to improve the symptoms of RLS in dialysis patients.

Medical Case Report on Repeat Treatment of Restless Legs Syndrome with Intravenous Infusion of Iron

Restless legs syndrome (RLS) is a debilitating neurological disorder for which a range of medical interventions with varied efficacy has been employed. Based on evidence of iron deficiency in the substantia nigra of the midbrain, there are reports of substantial benefits from intravenous iron infusion. This case report demonstrates a strong statistically significant negative correlation between serum ferritin and RLS severity of symptoms in a subject with RLS who received 2 intravenous infusions of ferric carboxymaltose over a period of 464 days. The results provide further evidence to support the treatment strategy.

The relationship between sleep disorders, anxiety, depression, and cognitive function with restless legs syndrome (RLS) in the elderly

OBJECTIVES

Restless legs syndrome (RLS) has a significant effect on sleep and quality of life. Delays in diagnosis and treatment are frequent due to a lack of awareness. In this study, a clinical analysis was performed to examine the relationship between sleep, mood, and cognitive function in RLS.

METHODS

According to the Pittsburgh Sleep Quality Index score (PSQI), patients with RLS were divided into a sleep disorders group (SD, PSQI > 7) and non-sleep disorders group (NSD, PSQI ≤ 7). Healthy controls were selected as a control group matched for age, cultural background, and marital status. We compared differences between the three groups using the Hamilton Anxiety Scale (HAMA), Hamilton Depression (HAMD), Mini-Mental State Examination (MMSE), and Montreal Cognitive Assessment (MoCA). The SD and NSD groups were also assessed with the Restless Leg Syndrome Rating Scale (RLSRS) and the severity of RLS between the two groups was compared. The analysis used t-test, ANOVA, and Pearson correlation.

RESULTS

(1) Among the 54 RLS patients, 30 people in the control group, 35 patients with sleep disorders (SD, 65%), and 19 patients without sleep disorders (NSD, 35%), there were no significant differences in age, educational level, marital status, or trauma history. (2) The comparison results of the case group (SD and NSD) and the control group showed highly significant differences (P < 0.01) in the PSQI-HAMA-HAMD score but no significant differences between the NSD group, the SD group, and the control group in MMSE score. There was no difference between the NSD group and the control group in the MoCA, but a significant difference (P < 0.05) between the SD group and the control group was found. (3) The comparison between the NSD and the SD groups revealed significant differences in the RLSRS, HAMA, and HAMD scores (P < 0.05), but there were no statistical differences (P > 0.05) between two groups on MMSE and MoCA score. (4) Correlation and regression showed that there was a linear correlation between PSQI scores and RLSRS and HAMD scores in patients with RLS (P < 0.05). The regression equation was PSQI =  - 2.393 + 0.494 RLSRS + 0.170 HAMD.

CONCLUSIONS

RLS patients were prone to sleep disorders, anxiety, and depression. Sleep disorders increased with the severity of the RLS and had some influence on the patient's cognitive function. Sleep disorders were closely related to RLSRS and HAMD.

High National Rates of High-Dose Dopamine Agonist Prescribing for RLS

Study Objectives

Long-term dopamine agonist (DA) use in restless legs syndrome (RLS) is associated with augmentation, a dose-related symptom worsening leading to further dose escalation to manage RLS. This study investigated rates and factors of high-dose DA prescribing in US RLS patients.

Methods

This retrospective analysis examined data from a US longitudinal prescriptions database (October 2017–September 2018). Patients diagnosed with RLS (ICD-10 G255.81) without Parkinson’s disease who were prescribed ropinirole, pramipexole, and/or rotigotine were included. Daily DA dosage was categorized: LOW/MID (US Food and Drug Administration [FDA]-approved/guideline or slightly above FDA-approved [pramipexole]); HIGH (101%–149%); VERY HIGH (>150%). Patient counts were converted to US national estimates. Logistic regression of patient counts evaluated factors associated with HIGH/VERY HIGH DA dosing.

Results

Of 670,404 RLS patients (131,289,331 therapy days), 58.8% were prescribed DA therapy. Overall, 19.1% of RLS patients were prescribed DAs above maximum FDA-approved/guideline daily doses—over half of these were >150% maximum recommended doses; 67.6% of HIGH/VERY HIGH-dose prescriptions were pramipexole (OR [95% CI] pramipexole vs ropinirole, 5.8 [5.7 to 6.0]). The highest 1% of DA prescriptions were ≥10× the FDA-recommended maximum daily dose. Rates of HIGH/VERY HIGH DA dosing increased with patient age. Twice as many neurologists (31.1%) prescribed HIGH/VERY HIGH doses vs other specialties (OR [95% CI], 2.1 [1.2 to 2.0]).

Conclusions

Approximately 20% of DA-treated RLS patients were prescribed doses above the approved and guideline daily maximum. Pramipexole, Neurology as specialty, and patient age were independently associated with HIGH/VERY HIGH DA dosing. Increased education is warranted regarding risks of high-dose DA exposure in RLS.

Dopamine agonist responsive burning mouth syndrome: Report of eight cases

BACKGROUND

Burning mouth syndrome (BMS) is characterized by burning sensation of the oral mucosa. There is a lack of effective treatment. In recent years, a special subtype of BMS has been reported, in which oral burning sensation is alleviated after chewing, speaking, or dopaminergic drug delivery. Currently, there are few reports about the subtype of BMS in China. This study was a retrospective analysis of the clinical data of BMS patients sensitive to dopamine agonist at our hospital, aiming to improve the recognition on this disease.

CASE SUMMARY

Eight patients diagnosed with dopamine agonist responsive BMS at the Liaocheng People's Hospital from January 1, 2017 to June 30, 2020 were recruited. The clinical manifestations, treatment, and prognosis were retrospectively analyzed. There were three male and five females in the eight patients. The median age was 56 years (range, 46-65 years). All the eight patients showed burning pain in the mouth. The symptoms were mild in the morning and severe in the evening, and alleviated after chewing, talking, and other oral activities. Four patients were accompanied by restless legs syndrome (RLS). Family history of RLS was positive in two patients. All patients were treated with pramipexol, and symptoms were basically relieved after 2-8 wk.

CONCLUSION

Dopamine agonist responsive BMS is a special subtype of BMS, which is alleviated after oral activities. Dopamine receptor agonist is an effective treatment.

Best Practices in the Clinical Management of Progressive Supranuclear Palsy and Corticobasal Syndrome: A Consensus Statement of the CurePSP Centers of Care

Progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS; the most common phenotype of corticobasal degeneration) are tauopathies with a relentless course, usually starting in the mid-60s and leading to death after an average of 7 years. There is as yet no specific or disease-modifying treatment. Clinical deficits in PSP are numerous, involve the entire neuraxis, and present as several discrete phenotypes. They center on rigidity, bradykinesia, postural instability, gait freezing, supranuclear ocular motor impairment, dysarthria, dysphagia, incontinence, sleep disorders, frontal cognitive dysfunction, and a variety of behavioral changes. CBS presents with prominent and usually asymmetric dystonia, apraxia, myoclonus, pyramidal signs, and cortical sensory loss. The symptoms and deficits of PSP and CBS are amenable to a variety of treatment strategies but most physicians, including many neurologists, are reluctant to care for patients with these conditions because of unfamiliarity with their multiplicity of interacting symptoms and deficits. CurePSP, the organization devoted to support, research, and education for PSP and CBS, created its CurePSP Centers of Care network in North America in 2017 to improve patient access to clinical expertise and develop collaborations. The directors of the 25 centers have created this consensus document outlining best practices in the management of PSP and CBS. They formed a writing committee for each of 12 sub-topics. A 4-member Steering Committee collated and edited the contributions. The result was returned to the entire cohort of authors for further comments, which were considered for incorporation by the Steering Committee. The authors hope that this publication will serve as a convenient guide for all clinicians caring for patients with PSP and CBS and that it will improve care for patients with these devastating but manageable disorders.