The restless legs syndrome

Síndrome das pernas inquietas: diagnóstico e tratamento. Opinião de especialistas brasileiros

Este artigo contém as conclusões de reunião de 17-18 de novembro de 2006 do Grupo Brasileiro de Estudo em Síndrome das Pernas Inquietas (GBE-SPI) sobre diagnóstico e tratamento de SPI. Reiterou-se que se trata de condição de diagnóstico exclusivamente clínico, caracterizada por sensação anormal localizada, sobretudo, mas não exclusivamente, em membros inferiores, com piora noturna e alívio por movimentação da parte envolvida. Agentes terapêuticos com eficácia comprovada por estudos classe I são agonistas dopaminérgicos, levodopa e gabapentina enquanto que ácido valpróico de liberação lenta, clonazepam, oxicodona e reposição de ferro têm eficácia sugerida por estudos classe II. As recomendações do GBE-SPI para manejo de SPI primária são medidas de higiene do sono, suspensão de agentes agravantes de SPI, tratamento de comorbidades e agentes farmacológicos. Para estes as drogas de primeira escolha são agentes dopaminérgicos; segunda escolha são gabapentina ou oxicodona; e terceira escolha são clonazepam ou ácido valpróico de liberação lenta.

A genetic risk factor for periodic limb movements in sleep

BACKGROUND

The restless legs syndrome (RLS) is a common neurologic disorder characterized by an irresistible urge to move the legs. It is a major cause of sleep disruption. Periodic limb movements in sleep are detectable in most patients with RLS and represent an objective physiological metric.

METHODS

To search for sequence variants contributing to RLS, we performed a genomewide association study and two replication studies. To minimize phenotypic heterogeneity, we focused on patients with RLS who had objectively documented periodic limb movements in sleep. We measured serum ferritin levels, since iron depletion has been associated with the pathogenesis of RLS.

RESULTS

In an Icelandic discovery sample of patients with RLS and periodic limb movements in sleep, we observed a genomewide significant association with a common variant in an intron of BTBD9 on chromosome 6p21.2 (odds ratio, 1.8; P=2x10(-9)). This association was replicated in a second Icelandic sample (odds ratio, 1.8; P=4x10(-4)) and a U.S. sample (odds ratio, 1.5; P=4x10(-3)). With this variant, the population attributable risk of RLS with periodic limb movements was approximately 50%. An association between the variant and periodic limb movements in sleep without RLS (and the absence of such an association for RLS without periodic limb movements) suggests that we have identified a genetic determinant of periodic limb movements in sleep (odds ratio, 1.9; P=1x10(-17)). Serum ferritin levels were decreased by 13% per allele of the at-risk variant (95% confidence interval, 5 to 20; P=0.002).

CONCLUSIONS

We have discovered a variant associated with susceptibility to periodic limb movements in sleep. The inverse correlation of the variant with iron stores is consistent with the suspected involvement of iron depletion in the pathogenesis of the disease.

Cutaneous silent period in patients with restless leg syndrome

OBJECTIVE

To investigate the pathophysiological relationship between RLS and small fiber neuropathy using the cutaneous silent period (CSP), which is a spinal reflex mediated by Adelta cutaneous afferents and is useful for the evaluation of small-diameter nerve function.

METHODS

The CSP was measured from the extensor digitorum brevis in 157 patients with RLS and 60 healthy controls. The CSP measurement was repeated in the RLS patients after dopamine agonist treatment for one month. The RLS rating scale for clinical severity was used to evaluate each patient before and after treatment. The measured CSP variables were compared between the patient group and the control group. In addition, the possible correlation between the CSP variables and the RLS rating scale score related to treatment was analyzed.

RESULTS

The mean CSP latencies did not differ between the RLS patients and the healthy controls; however, the mean CSP duration was significantly longer in the RLS patients than in the controls, and this prolonged CSP duration improved to the level of the control subjects after dopamine agonist treatment (p=0.003). The mean RLS rating scale score also significantly decreased after medication (p=0.000). However, the changes in the CSP variables did not correlate with the decrement in the RLS rating scale score.

CONCLUSIONS

Although our results do not support the role of Adelta fiber dysfunction in RLS, the observed change in CSP duration may be useful as a clinical measure of the improvement with dopamine agonist treatment in patients with RLS.

SIGNIFICANCE

Further study is needed to elucidate the exact mechanism involved in the prolonged CSP duration in response to treatment.

Restless legs syndrome: diagnostic assessment and the advantages and risks of dopaminergic treatment

In the past few years, major advances have been made in the field of restless legs syndrome (RLS). New tools have been developed to assess the presence and severity of RLS and its complications. Furthermore new concepts of the phenotype are emerging.With a high likelihood a slight dopaminergic hypofunction contributes essentially to the pathophysiology of most phenotypes of RLS. Dopaminergic substitution either with L-DOPA or with dopamine agonists ameliorates symptoms in the large majority of patients. Too high of doses of either type of drug may be involved in the development of augmentation caused by treatment-induced alterations in dopaminergic neurotransmission. Dopaminergic agents are currently the agents of first choice to treat RLS, and large multicenter trials support the evidence of efficacy. Very careful tailoring of the dose is required to avoid the development of treatment complications, specifically augmentation.

Skeletal Muscle Morphology in Patients with Restless Legs Syndrome

AIM

The aim of the study was to assess the cellular and structural properties of skeletal muscle in restless legs syndrome (RLS).

METHOD

Twenty patients and 16 controls were included. Aerobic performance was assessed using a submaximal test. On muscle biopsies taken from the tibialis anterior, fiber distribution and fiber area were analyzed together with parameters surveying the microvascularization, especially the tortuosity, which is expressed as a percent of muscle fiber perimeter in contact with the wall of the microvessel, length of capillary/perimeter of fiber (LC/PF) index.

RESULTS

The RLS group had significantly lower predicted maximal oxygen uptake (p = 0.01) and significantly higher LC/PF index (p = 0.01) compared to the controls.

CONCLUSION

The higher capillary tortuosity in RLS patients indicates the occurrence of significant remodeling in capillary geometry in RLS.

Efficacy of rotigotine transdermal system in severe restless legs syndrome: a randomized, double-blind, placebo-controlled, six-week dose-finding trial in Europe

BACKGROUND

In a pilot placebo-controlled study, low dosages of 0.5-2mg/24h rotigotine showed a dose-dependent beneficial effect in restless legs syndrome (RLS) patients.

METHODS

Efficacy and safety of the dopamine agonist rotigotine, formulated as a once-daily transdermal system (patch), was investigated for five fixed dosages and compared to placebo in patients with idiopathic RLS in a double-blind, randomized, parallel-group, multicenter, six-week dose-finding trial. Primary efficacy measure was the total score of the International RLS Severity Scale (IRLS); in addition, the RLS-6 scales and the Clinical Global Impressions (CGI) were administered.

RESULTS

Of 371 enrolled patients, 341 patients (mean age 58+/-10years, 67% females) were randomized. The IRLS total score improved between baseline and end of the six-week treatment period by -10.6 (0.5mg/24h rotigotine; patch area 2.5cm2), -15.1 (1mg/24h; 5cm2), -15.7 (2mg/24h; 10cm2), -17.5 (3mg/24h; 15cm2), and -14.8 (4mg/24h, 20cm2) as compared to placebo (-9.2). The hierarchical statistical test procedure demonstrated superiority of rotigotine over placebo for 4mg/24h, 3mg/24h, 2mg/24h, and 1mg/24h, with p-values of 0.0013, <0.0001, 0.0003, and 0.0004, respectively. Only the 0.5mg/24h dose was not different compared to placebo (p=0.2338). The CGI and the RLS-6 severity items supported the efficacy of the rotigotine doses beyond 0.5mg/24h. The most frequent side effects were application site reactions and nausea and tended to be more frequent with higher doses.

CONCLUSIONS

This dose-finding trial identified the range for a maintenance dose of rotigotine from 1mg/24h to 3mg/24h. The lowest dose was ineffective and, with the highest dose, no additional benefit was observed.

Pathophysiological concepts of restless legs syndrome

Pathophysiological concepts of restless legs syndrome (RLS) are based mainly on neuroimaging and on neurophysiological data. Furthermore treatment effects contribute essentially to the present understanding of the disease, unless the genetic progress expected in the near future will clarify substantially open issues. The concept agreed on assumes a dysfunction of the dopaminergic system, possibly on the level of striatal and/or spinal dopamine receptors, and the A11 neuron group localized in the hypothalamus as an integrated part of the system. These neurons modulate spinal excitability, alterations of which in turn affect sensory processing predominantly of leg afferents in brain stem structures. Neurophysiologically excitability alterations can be measured by a variety of methods such as determination of pain thresholds, H-reflex testing, and quantitative sensory testing.

Pregabalin in restless legs syndrome with and without neuropathic pain

BACKGROUND

Restless legs syndrome (RLS) is a common neurological disorder complicated in many patients by augmentation to dopaminergic therapy or comorbidities such as neuropathic pain.

AIMS

To explore the effectiveness of pregabalin in RLS in a pragmatic clinical setting.

METHODS

After observing improvement of restless legs symptoms in seven patients treated with pregabalin for neuropathic pain, we extended the clinical observation to a total of 16 patients with secondary RLS, in most of them due to neuropathy, and to three patients with idiopathic RLS.

RESULTS

Three patients discontinued pregabalin because of side effects (rash, fatigue, loss of efficacy). The other 16 patients self-rated a satisfactory or good alleviation of RLS symptoms and maintained pregabalin, five with add-on medication, on a mean daily dose of 305 mg (standard deviation, 185 mg), and with a mean duration of 217 (standard deviation, 183) days.

CONCLUSION

These data propose pregabalin as a new option in the treatment of secondary RLS for patients with neuropathic pain, which should be further investigated with randomized, placebo-controlled trials.

Can botulinum toxin put the restless legs syndrome to rest?

The restless legs syndrome (RLS), affecting between 3% and 15% of the population, is characterised by an urge to move the legs during wakefulness, associated with a range of unpleasant sensory symptoms, especially when sitting or lying down at night. The symptoms can even be painful, and lead to sleep disturbances and depression. RLS is treated with dopaminergic agents, anticonvulsants, opioids, clonidine and benzodiazepines. In a small percentage of cases, RLS is refractory to treatment, requiring combination therapy. Botulinum toxin (BTX), derived from the exotoxin of Clostridium botulinum, cleaves soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, causing chemodenervation of cholinergic neurons. BTX has been demonstrated to ameliorate pain syndromes, possibly by reducing peripheral and central sensitization to pain. We postulate that BTX can be injected subcutaneously to the lower limbs to effect amelioration of the symptoms of RLS.

Drugs for sleep disorders: mechanisms and therapeutic prospects

The past decade has witnessed an explosion of knowledge about the neural mechanisms that control sleep and arousal, triggered by two discoveries relating to the sleep disorder narcolepsy. Narcolepsy is caused by the loss of orexin-containing neurons in the hypothalamus, and a novel nonstimulant wakefulness-promoting drug, modafinil, alleviates excessive day-time sleepiness associated with the disorder. The level of arousal is controlled by an intricate interplay between distinct wakefulness- and sleep-promoting nuclei situated in the hypothalamus and brainstem and the interconnections between the nuclei and the neurotransmitters involved have been mapped. Wakefulness-promoting nuclei include the orexinergic lateral hypothalamic/perifornical area, the histaminergic tuberomammillary nucleus, the cholinergic pedunculopontine tegmental nucleus, the noradrenergic locus coeruleus, the 5-hydroxytryptaminergic raphe nuclei and possibly the dopaminergic ventral tegmental area. The major sleep-promoting nucleus is the GABAergic ventrolateral preoptic nucleus of the hypothalamus. Currently available and future drugs exert their therapeutic effects in the three major classes of sleep disorder (insomnia, hypersomnia, parasomnia) by modifying neurotransmission at distinct sites within the arousal-controlling neuronal network. This enables classification of therapeutic drugs for sleep disorders on the basis of their modes of action: drugs that interact with the GABAergic sleep-promoting system, drugs that interact with different wakefulness-promoting systems and drugs that modulate the level of arousal by mechanisms that do not initially involve the basic network (e.g. melatonin, adenosine). The development of novel therapeutic drugs for sleep disorders is based on the synthesis of molecular/cellular mechanisms and the sites of action within the arousal-controlling neuronal network.

Rotigotine: transdermal dopamine agonist treatment of Parkinson's disease and restless legs syndrome

OBJECTIVE

To evaluate the pharmacology, pharmacokinetics, clinical efficacy, and tolerability of rotigotine, a nonergoline D(3)/D(2)/D(1) dopamine receptor agonist in the treatment of Parkinson's disease and restless legs syndrome (RLS).

DATA SOURCES

A literature search was conducted using MEDLINE (1996-December 2006) and International Pharmaceutical Abstracts, using the search terms rotigotine and dopamine agonist. References cited in the articles were reviewed for additional information. Information was also obtained from Schwarz Pharma. Abstracts for posters at scientific conferences were accessed from conference Web sites.

STUDY SELECTION AND DATA EXTRACTION

English-language literature reporting controlled animal and human clinical studies was reviewed to evaluate the pharmacology, pharmacokinetics, therapeutic use, and adverse effects of rotigotine. Clinical trials selected for inclusion were limited to those with human subjects; data from animal studies were included if human data were not available.

DATA SYNTHESIS

Rotigotine has been investigated in early Parkinson's disease, as adjuvant therapy to levodopa in advanced Parkinson's disease, and in RLS. It is administered transdermally, which provides the convenience of once-daily dosing, constant drug delivery, and sustained stable plasma concentrations. In clinical trials of patients with early Parkinson's disease, rotigotine has decreased combined scores on the motor and activities of daily living sections of the Unified Parkinson's Disease Rating Scale up to 85 weeks. In patients with advanced Parkinson's disease, rotigotine reduced mean off-time when used as an adjuvant to levodopa. Rotigotine has decreased the severity of RLS in Phase III trials. Acute adverse events are similar to those of other dopamine agonists and are most common during the titration phase. Mild-to-moderate application site reactions are common.

CONCLUSIONS

Longer trials are required to determine whether transdermal rotigotine will reduce development of dyskinesias and motor fluctuations in Parkinson's disease and augmentation and rebound in RLS by preventing pulsatile dopamine stimulation associated with levodopa and other dopamine agonists.

Restless legs syndrome induced by citalopram: a psychiatric emergency?

OBJECTIVE

The objective of this case report is to create awareness on restless legs syndrome (RLS) among clinicians working in emergency units.

METHOD

We describe a case reporting important aggravation of RLS associated with citalopram, 60 mg/day, in a 48-year-old woman who was sent to the emergency unit by her general practitioner. Citalopram was replaced by bupropion, 150 mg/day, and sertraline, 50 mg/day.

RESULTS

Three days later, symptoms of RLS started to diminish and, after 3 weeks, clinical symptoms had disappeared entirely. On 6-month follow-up, the patient did not manifest clinically significant RLS. Ignoring RLS could lead to a worsening of symptoms and could increase the risk for iatrogenic conditions. The prevalence of RLS in the general population is 3-9%; nevertheless, this syndrome is frequently underdiagnosed.

CONCLUSION

This case report suggests that RLS could be considered as a possible "dopamine-dependent side effect" of selective serotonin reuptake inhibitors (SSRIs). Bupropion could potentially "correct" dopaminergic dysfunction in RLS, and sertraline appears to be the SSRI that provides the least risk of RLS by blocking dopamine reuptake.

Cabergoline compared to levodopa in the treatment of patients with severe restless legs syndrome: Results from a multi-center, randomized, active controlled trial

We report the first large-scale double-blind, randomly assigned study to compare two active dopaminergic therapies for Restless Legs Syndrome (RLS), the dopamine agonist cabergoline (CAB) and levodopa/benserazide (levodopa). Patients with idiopathic RLS were treated with fixed daily doses of 2 or 3 mg CAB or 200 or 300 mg levodopa for 30 weeks. Efficacy was assessed by changes in the IRLS (International RLS Severity Scale) and by time to discontinuation of treatment due to loss of efficacy or augmentation. 361 of 418 screened patients (age 58 +/- 12 years, 71% females) were randomly assigned and treated (CAB: n = 178; levodopa: n = 183) in 51 centers of four European countries. Baseline IRLS total score was 25.7 +/- 6.8. The baseline-adjusted mean change from baseline to week 6 in IRLS sum score was d = -16.1 in the CAB group and d = -9.5 in the levodopa group (d = -6.6, P < 0.0001). More patients in the levodopa group (24.0%) than in the CAB group (11.9%, P = 0.0029, log-rank test) discontinued because of loss of efficacy (14.2% vs. 7.9%, P = 0.0290) or augmentation (9.8% vs. 4.0%, P = 0.0412). Adverse events (AEs) occurred in 83.1% of the CAB group and in 77.6% of the levodopa group. In both groups, most frequent AEs were gastrointestinal symptoms (CAB: 55.6%, levodopa: 30.6%, P < 0.0001). This first large-scale active controlled study in RLS showed superior efficacy of cabergoline versus levodopa after a 30-week long-term therapy. Tolerability was found more favorable with levodopa than with cabergoline.

Medication tolerance and augmentation in restless legs syndrome: the need for drug class rotation

Restless legs syndrome (RLS) is a common condition characterized by an unpleasant urge to move the legs that usually occurs at night and may interfere with sleep. The medications used most commonly to treat RLS include dopaminergic drugs (levodopa, dopamine agonists), benzodiazepines, and narcotic analgesics. We report the cases of 2 patients with RLS who illustrate the problems of tolerance (declining response over time) and augmentation (a worsening of symptoms due to ongoing treatment) that can complicate the pharmacotherapy of RLS. We discuss the optimal management of RLS and propose strategies to overcome tolerance and augmentation such as a rotational approach among agents from different classes.

Rotigotine transdermal system: a short review

Rotigotine (Neupro((R))) is a new non-ergolinic dopamine agonist transdermal patch that can be applied once daily. To date, it is approved for the treatment of early Parkinson's disease as monotherapy and has been shown to be effective in the treatment of advanced-stage Parkinson's disease and restless legs syndrome in several clinical trials. This review gives an overview of physical, chemical, and pharmaceutical characteristics, pharmacokinetics, biotransformation and elimination, drug interactions, and adverse events of rotigotine. Further, the rationale for the treatment of Parkinson's disease and restless legs syndrome with rotigotine is discussed.

Restless Legs Syndrome in Hereditary Spastic Paraparesis

This study was designed to investigate the prevalence and determinants of the association of restless legs syndrome (RLS) and hereditary spastic paraparesis (HSP). Therefore, 132 patients with HSP were evaluated concerning the symptoms of RLS by a standardized questionnaire. RLS was supposed when patients met all of the established four essential criteria of RLS defined by the International RLS Study Group. In addition, we studied the relationship between RLS and age at HSP symptom onset and evaluated the severity of RLS symptoms. Out of 59 responses, RLS was found in 27 HSP patients (15 male, 12 female) so that RLS was more frequent in the total HSP group (20.5%; 27/132) than in previous population-based studies (about 11%). In all 27 patients, the diagnosis of RLS was established based on an additional personal interview. The probability to develop RLS did not increase with higher age. Age at onset of HSP symptoms in the HSP group with RLS (27.7 +/- 12.6 years) and the HSP group without RLS (37.0 +/- 16.9 years) differed significantly (p = 0.04). Most of the patients with RLS showed a moderate and severe grade on the RLS severity score. Only 8 patients had previously been diagnosed to have RLS and were on medication. The data of this screening for RLS provided evidence that patients with HSP are particularly susceptible to develop RLS. Consequently, special emphasis should be put on the diagnosis criteria of RLS in HSP patients.

Genetics of the sleep-wake cycle and its disorders

The sleep-wake cycle is under the control of the circadian clock. Recent advances in rhythm biology have identified molecular clocks and their key regulating genes. Circadian clock genes (Clock, Per) were first isolated in Drosophila, and their homologous counterparts have been found in mammals. Some of the circadian master genes have been shown to influence sleeping behavior. For instance, a point mutation in a human clock gene (Per2) was shown to produce the rare advanced sleep phase syndrome, whereas a functional polymorphism in Per3 is associated with the more frequent delayed sleep phase syndrome. Furthermore, a study examining the association between Clock gene polymorphisms and insomnia revealed a higher recurrence of initial, middle, and terminal insomnia in patients homozygous for the Clock genotype. Other genes have been shown to contribute to sleep pathologies. A point mutation in the prion protein gene appears to be the cause of fatal familial insomnia. A missense mutation has been found in the gene encoding the GABA-A beta 3 subunit in a patient with chronic insomnia. In both animal models and humans, a deficiency in the hypocretin/orexin system was proposed to be responsible for narcolepsy. Selective destruction of hypocretin neurons is the most probable culprit in humans. These findings suggest that the genetic contribution to sleep disorders and wake determinants is more important than originally thought. Beyond sleep, light/dark cycles and sleep deprivation appear also to be associated with eating habits, and epidemics of obesity have to be evaluated in the context of shortened sleep duration.

Linkage analysis identifies a novel locus for restless legs syndrome on chromosome 2q in a South Tyrolean population isolate

Restless legs syndrome (RLS) is a common neurological condition with three loci (12q, 14q, and 9p) described so far, although none of these genes has yet been identified. We report a genomewide linkage scan of patients with RLS (n=37) assessed in a population isolate (n=530) of South Tyrol (Italy). Using both nonparametric and parametric analyses, we initially obtained suggestive evidence of a novel locus on chromosome 2q, with nominal evidence of linkage on chromosomes 5p and 17p. Follow-up genotyping yielded significant evidence of linkage (nonparametric LOD score 5.5, P Collapse

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MESH Headings

• Adolescent
• Adult
• Child
• Chromosome Mapping
• Chromosomes, Human, Pair 2/genetics
• Family
• Female
• Genetic Linkage
• Genetic Predisposition to Disease
• Genome, Human
• Humans
• Italy
• Lod Score
• Male
• Microsatellite Repeats
• Middle Aged
• Pedigree
• Restless Legs Syndrome/genetics

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Grants Collapse

Affiliation(s)

Irene Pichler Institute of Genetic Medicine, European Academy, Bolzano, Italy
Fabio Marroni
Claudia Beu Volpato
James F Gusella
Christine Klein
Giorgio Casari
Alessandro De Grandi
Peter P Pramstaller

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A new look at an under-diagnosed poorly treated condition: Restless legs syndrome

Restless legs syndrome (RLS) is a common condition that is difficult to diagnose. However, once correctly diagnosed, its management is straightforward and evidence-based. The purpose of this article is to familiarise clinicians with both the symptoms and diagnostic criteria for RLS and to elucidate secondary and often curable causes of this prevalent condition. There is also a concise review of its pathophysiology and current management strategies. The authors hope this article will raise awareness of this condition among clinicians and in doing so improve the quality of life for the patients affected by it.

Less is more: pathophysiology of dopaminergic-therapy-related augmentation in restless legs syndrome

Therapy-related augmentation of the symptoms of restless legs syndrome (RLS) is an important clinical problem reported in up to 60% of patients treated with levodopa and, to a lesser extent, with dopamine agonists. The efficacy of low-dose dopaminergic drugs for RLS has been established, but the mode of action is unknown. Here, we review the existing data and conclude that augmentation is a syndrome characterised by a severely increased dopamine concentration in the CNS; overstimulation of the dopamine D1 receptors compared with D2 receptors in the spinal cord may lead to D1-related pain and generate periodic limb movements; iron deficiency may be a main predisposing factor of augmentation, probably caused by a reduced function of the dopamine transporter; therapy with levodopa or dopamine agonists should remain at low doses and; iron supplementation and opiates are the therapy of choice to counter augmentation.

The weight of evidence for ropinirole in restless legs syndrome

Evidence-based guidelines consider dopaminergic therapy to be the mainstay of treatment for restless legs syndrome (RLS). l-dopa has been shown to reduce RLS symptoms, but subsequent augmentation of symptoms occurs in up to 73% of patients during continued treatment. The ergot-derived dopamine agonist pergolide has been shown to be effective in small, open or placebo-controlled studies, but there have been reports of pleuropulmonary or cardiac valvular disease with this ergoline agent. Amongst the non-ergoline dopamine agonists, pramipexole has been reported to reduce RLS symptoms, but robust trial data are limited. By contrast, the RLS clinical trial programme with ropinirole is the largest published to date. This programme includes 12-week randomized double-blind placebo-controlled studies and a 36-week maintenance-of-effect study. Data from the placebo-controlled studies show that ropinirole, 0.25-4.0 mg/day, produces rapid and significant reductions, compared with placebo, in the sensory and motor symptoms of RLS, and that these benefits are associated with significant improvements in sleep and quality of life. In addition, the maintenance study has shown that these benefits are maintained during longer-term treatment. Furthermore, ropinirole is generally well tolerated. Ropinirole thus represents a potential valuable approach to the management of RLS.

Restless legs syndrome triggered by heart surgery

This report presents the case of a 9-year-old child with a familial history of restless legs syndrome who began to complain of restless legs syndrome symptoms after heart surgery. Hypotheses on the potential interactions between genetic and environmental factors in the development of her restless legs syndrome are discussed. Increasing evidence supports reduced brain iron in the pathophysiology of idiopathic restless legs syndrome. It is possible that the child inherited a compromised brain and peripheral iron regulation, which predisposed her to restless legs syndrome. The interaction between her dysfunctional iron management and her intraoperatory blood loss may have led to a significant decrease in brain iron, triggering restless legs syndrome symptoms. Other factors, such as immobilization and sleep deprivation after surgery, may have contributed to trigger the restless legs syndrome symptoms. If confirmed by further evidence, this patient suggests the need to carefully monitor for restless legs syndrome symptoms in young surgical patients who present with a familial history of restless legs syndrome.

Dopamine and the spinal cord in restless legs syndrome: Does spinal cord physiology reveal a basis for augmentation?

The pathophysiology of restless legs syndrome (RLS) is incompletely understood. L-DOPA, as the precursor of dopamine, as well as dopamine agonists, plays an essential role in the treatment of RLS leading to the assumption of a key role of dopamine function in the pathophysiology of RLS. Periodic limb movements in sleep are a key feature of RLS. They are generated in the spinal cord. Here we review RLS phenomenology on the basis of known dopaminergic influence on spinal control, which has been studied a great deal in recent decades in animals. In particular, we propose that the differential effects of l-DOPA and opioids on early and late flexor reflexes may be linked to the phenomenon of augmentation.

Restless legs syndrome and polyneuropathy

Restless legs syndrome (RLS), diagnosed according to the International RLS Study Group criteria, was investigated in 97 consecutive patients with polyneuropathy and found in 29 patients. RLS patients were more often women (22 of 29 vs. 33 of 68; P = 0.015), mainly with sensory neuropathy of small fiber type (15 of 29 vs. 16 of 68; P = 0.009). Changes of sensory action potentials were significantly less severe in RLS patients. In the RLS group, acquired neuropathies, and in particular dysimmune neuropathies, were significantly more frequent (27/29 vs. 46/68; P = 0.009). Thus, RLS is frequent in acquired polyneuropathy of sensory type and mild entity, mainly in women.

Síndrome das Pernas Inquietas

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