Genome-wide association study of restless legs syndrome identifies common variants in three genomic regions.

Restless legs syndrome (RLS) is a frequent neurological disorder characterized by an imperative urge to move the legs during night, unpleasant sensation in the lower limbs, disturbed sleep and increased cardiovascular morbidity. In a genome-wide association study we found highly significant associations between RLS and intronic variants in the homeobox gene MEIS1, the BTBD9 gene encoding a BTB(POZ) domain as well as variants in a third locus containing the genes encoding mitogen-activated protein kinase MAP2K5 and the transcription factor LBXCOR1 on chromosomes 2p, 6p and 15q, respectively. Two independent replications confirmed these association signals. Each genetic variant was associated with a more than 50% increase in risk for RLS, with the combined allelic variants conferring more than half of the risk. MEIS1 has been implicated in limb development, raising the possibility that RLS has components of a developmental disorder.

The PD-associated alpha-synuclein promoter Rep1 allele 2 shows diminished frequency in restless legs syndrome.

Gain-of-function mutations of alpha-synuclein (SNCA) are known to trigger Parkinson's disease (PD) with striatal dopaminergic deficits and a reduction of spontaneous movements. The longest size variant (allele 2) of the complex microsatellite repeat Rep1 within the SNCA gene promoter is known to confer a PD risk. We now observed this Rep1 allele 2 to show significantly decreased frequency in restless legs syndrome (RLS) in a genotyping study of 258 patients versus 235 healthy controls from Germany. Given that RLS is a disease with increased spontaneous movements and with increased striatal dopamine signaling, these novel data appear plausible. The scarcity of this alpha-synuclein gain-of-function variant in RLS might suggest that a low alpha-synuclein function via the SNARE complex in presynaptic vesicle release and neurotransmission of the striatum contributes to RLS pathogenesis.

Genome-wide association study identifies novel restless legs syndrome susceptibility loci on 2p14 and 16q12.1.

Restless legs syndrome (RLS) is a sensorimotor disorder with an age-dependent prevalence of up to 10% in the general population above 65 years of age. Affected individuals suffer from uncomfortable sensations and an urge to move in the lower limbs that occurs mainly in resting situations during the evening or at night. Moving the legs or walking leads to an improvement of symptoms. Concomitantly, patients report sleep disturbances with consequences such as reduced daytime functioning. We conducted a genome-wide association study (GWA) for RLS in 922 cases and 1,526 controls (using 301,406 SNPs) followed by a replication of 76 candidate SNPs in 3,935 cases and 5,754 controls, all of European ancestry. Herein, we identified six RLS susceptibility loci of genome-wide significance, two of them novel: an intergenic region on chromosome 2p14 (rs6747972, P = 9.03 × 10(-11), OR = 1.23) and a locus on 16q12.1 (rs3104767, P = 9.4 × 10(-19), OR = 1.35) in a linkage disequilibrium block of 140 kb containing the 5'-end of TOX3 and the adjacent non-coding RNA BC034767.

Unimpaired postprandial pancreatic polypeptide secretion in Parkinson's disease and REM sleep behavior disorder.

BACKGROUND: Pancreatic polypeptide is released immediately after food ingestion. The release is operated by vagal-abdominal projections and has therefore been suggested as a test for vagal nerve integrity. Pathoanatomical and clinical studies indicate vagal dysfunction in early Parkinson's disease (PD). METHODS: We assessed the postprandial secretion of pancreatic polypeptide and motilin in healthy controls (n = 18) and patients with idiopathic rapid-eye-movement sleep behavior disorder (iRBD, n = 10), a potential premotor stage of PD, as well as in drug-naive (n = 19) and treated (n = 19) PD patients. RESULTS: The postprandial pancreatic polypeptide secretion showed a physiological pattern in all groups and even an enhanced response in drug-naive PD and iRBD. Motilin concentrations correlated with pancreatic polypeptide concentrations. CONCLUSIONS: Postprandial pancreatic polypeptide secretion is not a suitable test for vagal nerve integrity in PD. The unimpaired pancreatic polypeptide response in iRBD and PD might be explained by partially intact vagal-abdominal projections or compensatory mechanisms substituting a defective neuronal brain-gut axis.

A single-question screen for rapid eye movement sleep behavior disorder: a multicenter validation study.

BACKGROUND: Idiopathic rapid eye movement (REM) sleep behavior disorder (RBD) is a parasomnia that is an important risk factor for Parkinson's disease (PD) and Lewy body dementia. Its prevalence is unknown. One barrier to determining prevalence is that current screening tools are too long for large-scale epidemiologic surveys. Therefore, we designed the REM Sleep Behavior Disorder Single-Question Screen (RBD1Q), a screening question for dream enactment with a simple yes/no response. METHODS: Four hundred and eighty-four sleep-clinic-based participants (242 idiopathic RBD patients and 242 controls) completed the screen during a multicenter case-control study. All participants underwent a polysomnogram to define gold-standard diagnosis according to standard criteria. RESULTS: We found a sensitivity of 93.8% and a specificity of 87.2%. Sensitivity and specificity were similar in healthy volunteers, compared to controls or patients with other sleep diagnoses. CONCLUSIONS: A single-question screen for RBD may reliably detect disease, with psychometric properties favorably comparable to those reported for longer questionnaires.

Patients with idiopathic rapid-eye-movement sleep behavior disorder show normal gastric motility assessed by the 13C-octanoate breath test.

BACKGROUND: Delayed gastric emptying is a non-motor symptom of Parkinson's disease. Few data exist on gastric emptying in early-stage Parkinson's disease. In idiopathic rapid-eye-movement sleep behavior disorder, a presumable pre-motor stage of Parkinson's disease, gastric emptying has not yet been investigated. METHODS: Twenty healthy controls, 13 patients with idiopathic rapid-eye-movement sleep behavior disorder, and 39 patients with Parkinson's disease patients underwent standardized testing for gastric emptying with the (13)C-octanoate breath test. RESULTS: Gastric emptying was significantly delayed in drug-naïve (P < .001) and in treated Parkinson's disease patients (P < .001), but normal in patients with idiopathic rapid-eye-movement sleep behavior disorder. CONCLUSIONS: Our study confirms delayed gastric emptying in drug-naïve, early-stage Parkinson's disease. Normal gastric emptying in idiopathic rapid-eye-movement sleep behavior disorder might be explained by the fact that neurodegenerative changes in structures modulating gastric motility are not severe enough to cause a functional deficit that can be detected by the (13)C-octanoate breath test.

Algorithms for the diagnosis and treatment of restless legs syndrome in primary care.

BACKGROUND: Restless legs syndrome (RLS) is a neurological disorder with a lifetime prevalence of 3-10%. in European studies. However, the diagnosis of RLS in primary care remains low and mistreatment is common. METHODS: The current article reports on the considerations of RLS diagnosis and management that were made during a European Restless Legs Syndrome Study Group (EURLSSG)-sponsored task force consisting of experts and primary care practitioners. The task force sought to develop a better understanding of barriers to diagnosis in primary care practice and overcome these barriers with diagnostic and treatment algorithms. RESULTS: The barriers to diagnosis identified by the task force include the presentation of symptoms, the language used to describe them, the actual term "restless legs syndrome" and difficulties in the differential diagnosis of RLS. CONCLUSION: The EURLSSG task force reached a consensus and agreed on the diagnostic and treatment algorithms published here.

Diffusion tensor imaging in idiopathic REM sleep behavior disorder reveals microstructural changes in the brainstem, substantia nigra, olfactory region, and other brain regions.

STUDY OBJECTIVES: Idiopathic rapid eye movement sleep behavior disorder (iRBD)--a parasomnia characterized by dream enactments--is a risk marker for the development of Parkinson disease (PD) and other alpha-synucleinopathies. The pathophysiology of iRBD is likely due to dysfunction of brainstem nuclei that regulate REM sleep. Diffusion tensor imaging (DTI) is a method for studying microstructural brain tissue integrity in vivo. We investigated whether DTI detects microstructural abnormalities in the brain of patients with iRBD--compared with age-matched control subjects--as an in vivo potential indicator for changes related to "preclinical (premotor)" neuropathology in PD. DESIGN: N/A. PATIENTS: Patients with iRBD (n = 12) and age-matched healthy control subjects (n = 12) were studied. INTERVENTIONS: At a 1.5T MRI maschine, whole-head DTI scans of fractional anisotropy, axial diffusivity (a potential marker of neuronal loss), and radial diffusivity (a potential marker of glial pathology) were analyzed using track-based spatial statistics, and 2 types of group analysis tools (FreeSurfer and FSL). MEASUREMENTS AND RESULTS: We found significant microstructural changes in the white matter of the brainstem (P < 0.0001), the right substantia nigra, the olfactory region, the left temporal lobe, the fornix, the internal capsule, the corona radiata, and the right visual stream of the patients with iRBD. CONCLUSIONS: Changes were identified in regions known to be involved in REM-sleep regulation and/or to exhibit neurodegenerative pathology in iRBD and/or early PD. The study findings suggest that iRBD-related microstructural abnormalities can be detected in vivo with DTI, a widely available MRI technique.

Treatment of moderate to severe restless legs syndrome: 2-year safety and efficacy of rotigotine transdermal patch.

BACKGROUND: Rotigotine is a unique dopamine agonist with activity across D1 through D5 receptors as well as select adrenergic and serotonergic sites. This study reports the 2-year follow-up safety and efficacy data of an ongoing open-label multicenter extension study (NCT00498186) of transdermal rotigotine in patients with moderate to severe restless legs syndrome (RLS). METHODS: Patients received a once-daily patch application of an individually optimized dose of rotigotine between 0.5 mg/24 h to 4 mg/24 h. Safety assessments included adverse events (AEs) and efficacy was measured by the International RLS Study Group Severity Rating Scale (IRLS), RLS-6 scales and Clinical Global Impression (CGI). Quality of life (QoL) was measured by QoL-RLS. RESULTS: Of 310 patients who completed a 6-week placebo-controlled trial (SP709), 295 (mean age 58 ± 10 years, 66% females) were included in the open-label trial SP710. 64.7% (190/295 patients) completed the 2-year follow-up; 29 patients discontinued during the second year. Mean daily rotigotine dose after 2 years was 2.93 ± 1.14 mg/24 h with a 2.9% dose increase from year 1. Rotigotine was generally well tolerated. The rate of typical dopaminergic side effects, nausea and fatigue, was low (0.9% and 2.3%, respectively) during the second year; application site reactions were frequent but lower than in year 1 (16.4% vs. 34.5%). The IRLS total score improved from baseline of SP709 (27.8 ± 5.9) by 17.2 ± 9.2 in year 2 completers. Similar improvements were observed in RLS-6 scales, CGI scores and QoL-RLS. The responder rate in the CGI change item 2 ("much" and "very much" improved) was 95% after year 2. CONCLUSIONS: Transdermal rotigotine is an efficacious and well-tolerated long-term treatment option for patients with moderate to severe RLS with a high retention rate during 2 years of therapy. TRIAL REGISTRATION: NCT00498186.

Assessing health-related quality of life in patients with restless legs syndrome.

BACKGROUND: Restless Legs Syndrome (RLS) has a substantial impact on normal daily activities. Because of the high prevalence it is necessary to evaluate the impact on the health-related quality of life (HRQoL). OBJECTIVE: To assess health-related quality of life in patients with RLS. METHODS: A total of 519 patients (327 female patients; mean age: 64.2 y) were recruited in five different German centers according to the diagnostic criteria of the International RLS Study Group. Patients were either interviewed or completed a mailed questionnaire. The questionnaire consisted of an evaluation of the sociodemographic, clinical and health-related status. HRQoL was evaluated with the EuroQoL (EQ-5D). In addition, the IRLS scale, the MOS Sleep Scale, the Epworth Sleepiness Scale, and the BDI were applied as clinical rating scales. RESULTS: HRQoL is substantially affected by RLS. The mean EQ-5D-VAS was 55.6 and considerably lower compared to the general population. It was found to be as low as in other chronic neurological disorders such as Parkinson's disease and stroke. From different factors investigated by uni- and multivariate analyses, severity of RLS and depressive symptoms had the most significant impact on HRQoL. Additionally, sleep deficits, the duration of the disease and net household income were identified as predictors for different EQ-5D outcome scores. CONCLUSIONS: RLS considerably affects HRQoL. Further comparative studies are necessary to evaluate the effect of disease symptoms on HRQoL and their change due to medication.

Continuous sleep EEG monitoring in PD patients with and without sleep attacks.

The pathogenesis of sleep attacks in Parkinson's disease (PD) is still unresolved. We investigated seven matched pairs of PD patients with and without a history of sleep attacks using continuous sleep EEG recording. According to the event marker altogether 12 sleep attacks were identified in three patients with a history of sleep attacks. All sleep attacks were characterized by NREM stage 1 and 2 sleep, whereas no sleep onset REM episodes were recorded. Five sleep attacks fulfilled our criteria for microsleep episodes lasting less than 120 s. The cumulative duration of microsleep episodes during the day was 27.7+/-20 min in patients with a history of sleep attacks vs. 6.4+/-4.1 min in patients without a history of sleep attacks (p=0.03), i.e., the majority of microsleep episodes were not perceived by the patients. In summary, our study suggests that sleep attacks are intrusions of NREM stage 1 and 2 sleep into wakefulness and can be identical to microsleep episodes. Future studies should systematically address the awareness of short sleep episodes in patients with PD and other disorders with increased daytime sleepiness.

Suggestive evidence for linkage for restless legs syndrome on chromosome 19p13.

Five loci for restless legs syndrome (RLS) on chromosomes 12q, 14q, 9p, 2q, and 20p (RLS1-RLS5) have been mapped in RLS families, with a recessive in the first and autosomal-dominant mode of inheritance in the latter cases. Investigations of further RLS families showed evidence for genetic locus heterogeneity. We have conducted a genome-wide linkage analysis in a large RLS family of Italian origin with 12 affected members in 3 generations using 5,861 single nucleotide polymorphisms (SNP, 6K Illumina). Linkage analysis was performed under an autosomal-dominant model with a complete penetrance, an allele frequency of 0.003 and a phenocopy rate of 0.005. The genome-wide scan resulted in suggestive evidence for linkage on chromosome 19p with maximum multipoint logarithm of the odds score of 2.61 between markers rs754292 and rs273265. The locus was replicated in a family-based association study in a set of 159 trios of European origin. This study provides evidence for a further RLS locus, thus supporting the picture of RLS as a genetically heterogenous complex trait.

Efficacy of rotigotine for treatment of moderate-to-severe restless legs syndrome: a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Continuous administration of a dopamine agonist could be used to treat patients with restless legs syndrome. Our aim was to investigate the efficacy of transdermal rotigotine in the treatment of idiopathic restless legs syndrome. METHODS: In this randomised, double-blind, placebo-controlled trial, 458 patients with moderate-to-severe idiopathic restless legs syndrome (average baseline International Restless Legs Syndrome Study Group severity rating scale [IRLS] sum score of 28.1) were randomly assigned to receive transdermal rotigotine 1 mg over 24 h (n=115), 2 mg over 24 h (n=112), or 3 mg over 24 h (n=114), or to receive placebo (n=117). Study medication was delivered via patches, applied once a day for 6 months. Randomisation was done with a computer-generated randomisation list, stratified by centre. Primary efficacy outcomes were absolute change from baseline to end of maintenance in IRLS sum score and in the clinical global impressions (CGI) item 1 score, assessed by analysis of covariance in the intention-to-treat population. This trial is registered with ClinicalTrials.gov, number NCT00136045. FINDINGS: Efficacy analyses were done on 112 patients in the 1 mg group, 109 in the 2 mg group, 112 in the 3 mg group, and 114 in the placebo group. Mean change in IRLS sum score from baseline at the end of the maintenance phase was -13.7 (SE 0.9) in the 1 mg group, -16.2 (0.9) in the 2 mg group, -16.8 (0.9) in the 3 mg group, and -8.6 (0.9) in the placebo group (p<0.0001 for treatment difference vs placebo with each dose). Mean change in CGI item 1 score from baseline at the end of the maintenance phase was -2.09 (0.14) in the 1 mg group, -2.41 (0.14) in the 2 mg group, -2.55 (0.14) in the 3 mg group, and -1.34 (0.14) in the placebo group (p<0.0001 for treatment difference vs placebo with each dose). Skin reactions, mostly mild or moderate, were seen in 145 (43%) of 341 patients who received rotigotine and in two (2%) of 117 who received placebo. Ten patients had serious adverse event that were deemed to be related to rotigotine: elevation of liver enzymes (one patient), worsening of tinnitus (one patient), non-response to anticoagulation (one patient), electrocardiogram changes (one patient), and application-site reactions (six patients). No admissions to hospital were needed for the application-site reactions, and they all resolved within a short time of patch removal without any other therapeutic intervention. The rate of typical dopaminergic side-effects in patients who received rotigotine was low; no signs of augmentation were noted. INTERPRETATION: 24 h transdermal delivery of low-dose rotigotine could be used to relieve the night-time and daytime symptoms of restless legs syndrome. FUNDING: Schwarz Biosciences.

Treatment of restless legs syndrome: an evidence-based review and implications for clinical practice.

Only in the last three decades, the restless legs syndrome (RLS) has been examined in randomized controlled trials. The Movement Disorder Society (MDS) commissioned a task force to perform an evidence-based review of the medical literature on treatment modalities used to manage patients with RLS. The task force performed a search of the published literature using electronic databases. The therapeutic efficacy of each drug was classified as being either efficacious, likely efficacious, investigational, nonefficacious, or lacking sufficient evidence to classify. Implications for clinical practice were generated based on the levels of evidence and particular features of each modality, such as adverse events. All studies were classed according to three levels of evidence. All Level-I trials were included in the efficacy tables; if no Level-I trials were available then Level-II trials were included or, in the absence of Level-II trials, Level-III studies or case series were included. Only studies published in print or online before December 31, 2006 were included. All studies published after 1996, which attempted to assess RLS augmentation, were reviewed in a separate section. The following drugs are considered efficacious for the treatment of RLS: levodopa, ropinirole, pramipexole, cabergoline, pergolide, and gabapentin. Drugs considered likely efficacious are rotigotine, bromocriptine, oxycodone, carbamazepine, valproic acid, and clonidine. Drugs that are considered investigational are dihydroergocriptine, lisuride, methadone, tramadol, clonazepam, zolpidem, amantadine, and topiramate. Magnesium, folic acid, and exercise are also considered to be investigational. Sumanirole is nonefficacious. Intravenous iron dextran is likely efficacious for the treatment of RLS secondary to end-stage renal disease and investigational in RLS subjects with normal renal function. The efficacy of oral iron is considered investigational; however, its efficacy appears to depend on the iron status of subjects. Cabergoline and pergolide (and possibly lisuride) require special monitoring due to fibrotic complications including cardiac valvulopathy. Special monitoring is required for several other medications based on clinical concerns: opioids (including, but not limited to, oxycodone, methadone and tramadol), due to possible addiction and respiratory depression, and some anticonvulsants (particularly, carbamazepine and valproic acid), due to systemic toxicities.

Assessment of idiopathic rapid-eye-movement sleep behavior disorder by transcranial sonography, olfactory function test, and FP-CIT-SPECT.

Idiopathic rapid-eye-movement (REM) sleep behavior disorder (iRBD) has been suggested to be a risk factor for subsequent development of neurodegenerative disorders, especially Parkinson's disease (PD) and other alpha-synucleinopathies. At present, it is not possible to predict whether or not an iRBD patient will eventually develop PD. Here, we report 5 iRBD patients who underwent a test battery comprising a neurological examination (including UPDRS rating), mini mental state examination testing, transcranial sonography, olfactory function testing, and presynaptic dopamine transporter imaging with FP-CIT-SPECT. Our preliminary data show the diverse pattern of individual combinations of pathological findings when a multimodal assessment approach is applied in this patient group. Large-size longitudinal studies in iRBD patients are required to evaluate the usefulness of diagnostic tests to identify the subgroup of iRBD patients that is prone to develop PD.

Variants in the neuronal nitric oxide synthase (nNOS, NOS1) gene are associated with restless legs syndrome.

Sixty percent of the patients with restless legs syndrome (RLS) report a positive family history. To date five loci have been mapped on chromosome 12q, 14q, 9p, 2q, and 20p (RLS1-5) but no gene has been identified so far. To identify genes related to RLS, we performed a three-stage association study (explorative study, replication study, high-density mapping) in two Caucasian RLS case-control samples of altogether 918 independent cases and controls. In the explorative study (367 cases and controls, respectively), we screened 1536 SNPs in 366 genes in a 21 Mb region encompassing the RLS1 critical region on chromosome 12. Armitage trend test revealed three genomic regions that were significant (P < 0.05). In the replication study (551 cases and controls, respectively) we genotyped the most significant SNPs of Stage 1. After correction for multiple testing, association was observed with SNP rs7977109 (P(nominal) = 0.00175, P(Westfall-Young) = 0.04895, OR = 0.76228, 95% CI = 0.64310-0.90355), which is in the neuronal nitric oxide synthase (NOS1) gene. High-density mapping using altogether 34 tagging and coding SNPs of the NOS1 gene in both case-control samples further confirmed the significant association results to NOS1. Ten more SNPs revealed significance with nominal P-values from 0.0001 to 0.0482 (genotypic test and Armitage test). Altogether, this study provides evidence for an association of variants in the NOS1 gene and RLS, and suggests the involvement of the NO/arginine pathway in the pathogenesis of RLS. Potential usage of NO modulating agents as new treatment options for RLS have become a challenging aspect for future research of this disorder.

One year open-label safety and efficacy trial with rotigotine transdermal patch in moderate to severe idiopathic restless legs syndrome.

BACKGROUND: Long-term efficacy and tolerability data are not yet available for patch formulations of dopamine agonists in restless legs syndrome. METHODS: Efficacy and safety of rotigotine (0.5-4mg/24h), formulated as a once-daily transdermal system (patch), were investigated in an open extension (SP710) of a preceding 6-week placebo-controlled trial (SP709, 341 randomized patients) in patients with idiopathic restless legs syndrome. For efficacy assessment the international RLS severity scale (IRLS), the RLS-6 scales, the clinical global impressions (CGI) and the QoL-RLS questionnaire were administered. In addition, long-term tolerability and safety were assessed. RESULTS: Of 310 patients who finished the controlled trial, 295 (mean age 58+/-10 years, 66% females) with a mean IRLS score of 27.8+/-5.9 at baseline of SP709 were included. We report results after one year of this ongoing long-term trial. Two hundred twenty patients (retention rate=74.6%) completed the 12-month follow-up period. The mean daily dose was 2.8+/-1.2mg/24h with 4mg/24h (40.6%) being the most frequently applied dose; 14.8% were sufficiently treated with 0.5 or 1.0mg/24h. The IRLS total score improved by ?17.4+/-9.9 points between baseline and end of Year 1 (p<0.001). The other measures of severity, sleep satisfaction and quality of life supported the efficacy of rotigotine (p<0.001 for pre-post-comparisons of all efficacy variables). The tolerability was described as "good" or "very good" by 80.3% of all patients. The most common adverse events were application site reactions (40.0%), which led to withdrawal in 13.2%. Further relatively frequent adverse events were nausea (9.5%) and fatigue (6.4%). Two drug-related serious adverse events, nausea and syncope, required hospitalization. Symptoms of augmentation were not reported by the patients. CONCLUSION: Rotigotine provided a stable, clinically relevant improvement in all efficacy measures throughout one year of maintenance therapy. The transdermal patch was safe and generally well tolerated by the majority of patients. Comparable to any transdermal therapy, application site reactions were the main treatment complication.

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.

Quantification of tonic and phasic muscle activity in REM sleep behavior disorder.

REM sleep behavior disorder (RBD) is characterized by excessive tone of the chin muscle and limb movement during sleep. In the past, quantification of increased muscle tone in REM sleep has been performed visually, using no stringent criteria. The aim of this study was to develop an automatic analysis, allowing the quantification of muscle activity and its amplitude for all sleep stages, with a focus on REM sleep in patients with RBD. Forty-eight patients (27 male, 21 female) with RBD were included in the analysis. Twenty-one had idiopathic RBD; 28 had narcolepsy plus RBD. Twenty-five patients without confirmed sleep disorder served as control subjects. The amplitude of the EMG was generated from the difference of the upper and lower envelope of the mentalis muscle recordings. By smoothing the amplitude curve, a threshold curve was defined. Any muscle activity beyond the threshold curve was defined as motor activity. The means of the motor activity per second were summarized statistically and calculated for each sleep stage. Due to variable distribution of REM sleep, the latter was assigned to respective quartiles of the recorded night. Muscle activity was defined according to a histogram as short-lasting (<0.5 second) and long-lasting (>0.5 second) activity. No difference in the distribution of REM sleep/quartile and mean muscle tone throughout the sleep cycle could be found within the RBD groups and control subjects. Muscle activity was in the range of 200 ms. No clusters or regular distribution of muscle activity were found. Long muscle activity in the group with manifest clinical RBD was significantly higher than in control subjects, whereas it was nonsignificantly higher in subclinical RBD. The correlation between the frequency of long muscle activity in REM sleep and age was highly significant only for patients with idiopathic RBD. Automatic analysis of muscle activity in sleep is a reliable, easy method that may easily be used in the evaluation for REM sleep behavior disorder, creating indices of muscle activity similar to the indices for sleep apnea or PLMS. Together with the overt behavior, the analyses provides an important tool to get a deeper insight into the pathophysiology of RBD. Long movements appear to represent the motor disinhibition in REM sleep more distinct than short movements. The positive correlation of age and increased motor activity in REM sleep in idiopathic RBD highlights the idea of age dependant motor disinhibition as a continuum of a neurodegenerative disorder, which in narcolepsy patients with RBD only seems to happen as a single temporal event at onset of the disorder.

Validation of the Augmentation Severity Rating Scale (ASRS): a multicentric, prospective study with levodopa on restless legs syndrome.

BACKGROUND: Augmentation is the main complication during long-term dopaminergic treatment of restless legs syndrome (RLS) and reflects an overall increase in RLS severity. Its severity varies considerably from a minor problem to a devastating exacerbation of disease. Despite its clinical relevance, systematic evaluations have rarely been undertaken and there has been no development of methods to assess the severity of augmentation. To fill this gap, the European RLS Study Group (EURLSSG) has developed the Augmentation Severity Rating Scale (ASRS), using three items that assess the degree of change in three specific dimensions of augmentation. The changes in each dimension are summed to give an ASRS total score. METHODS: The ASRS was developed to cover the basic dimensions defining RLS augmentation. The items were developed by an interactive process involving professional and patient input. The ASRS that was evaluated included four major items and two alternative forms of one item. The validation was conducted using 63 (85%) mostly untreated RLS patients from six centers, who were treated for six months with levodopa (L-Dopa) (up to 500 mg/day, as clinically needed). Two consecutive assessments before and at baseline measured test-retest reliability. Consecutive ASRS ratings by two independent raters on a subsample of patients evaluated inter-rater reliability. Comparison with clinical severity ratings of two independent experts provided external validation of the ASRS. Comparison of patients with and without augmentation with regard to the items and the total score of the ASRS added discriminant validity. RESULTS: Sixty patients (63% females, mean age: 53 years, baseline International RLS Severity Rating (IRLS) score 24.7+/-5.2) were treated with a median daily dose of 300 mg L-Dopa (range: 50-500 mg). Thirty-six patients (60%) experienced augmentation. Item analyses indicated that one item could be removed as it did not contribute significantly to the test score and only one form of the duplicated item needed to be used. The final ASRS then included three items. Test-retest reliability for the total score was rho=0.72, and inter-rater reliability was rcc=0.94. Cronbach's alpha was 0.62. Validity as assessed by the correlation between the worst ASRS total score during the trial and the expert rating was rho=0.72. ASRS total score differed between patients without versus with augmentation (mean: 7.4 (standard deviation (SD)=4.0) vs. 2.0 (2.7) (P<0.0001). CONCLUSIONS: The ASRS is a reliable and valid scale to measure the severity of augmentation. Due to the need to systematically quantify augmentation for both long-term efficacy and tolerability, the ASRS may become a useful tool to monitor augmentation in future clinical trials.