Restless Leg Syndrome
Current Research.
What is restless leg syndrome(RLS)? Does Restless Leg Syndrome affect women who have borne children more than women who haven't born children and men? What age group is the most prevelent for Restless Leg Syndrome and what drugs are most effective for Restless Leg syndrome.
Is there a possible genetic link? Is there a relationship to Parkinson's? The following research abstracts tries to answer these questions.
The symptoms for restless leg syndrome are that they occur during the night or periods of inactivity and often relieved by movement of the limb. There may be fatigue during the day because of difficulty of falling asleep or staying asleep at night. There may be involuntary jerking of the limbs while sleeping and even during periods of being awake.
RLS affects between eight and 15 percent of the population. What is also interesting is that mirapex, one of the drugs used for restless leg syndrome might help bipolar depression.
Arch Intern Med. 2004 Jan 26;164(2):196-202. :
Sex and the risk of restless legs syndrome in the general population.
Berger K, Luedemann J, Trenkwalder C, John U, Kessler C.
Institute of Epidemiology and Social Medicine, University of Munster, Germany.
bergerk@uni-muenster.de
BACKGROUND: Restless legs syndrome (RLS) is characterized by the desire to move the limbs associated with paresthesias of the legs, a motor restlessness, an intensification of symptoms at rest with relief by activity, and a worsening of symptoms in the evening or at night. Population-based studies are rare, and risk factors in the general population are not known. METHODS: Cross-sectional survey with face-to-face interviews and physical examination among 4310 participants in the Study of Health in Pomerania in northeastern Germany. Participants were aged 20 to 79 years and were randomly selected from population registers. Restless legs syndrome was assessed with standardized, validated questions addressing the 4 minimal criteria for RLS as defined by the International Restless Legs Syndrome Study Group. RESULTS: The overall prevalence of RLS was 10.6%, increasing with age, and women were twice as often affected as men. While nulliparous[childless] women had prevalences similar to those among men up to age 64 years, the risk of RLS increased gradually for women with 1 child (odds ratio, 1.98; 95% confidence interval, 1.25-3.13), 2 children (odds ratio, 3.04; 95% confidence interval, 2.11-4.40), and 3 or more children (odds ratio, 3.57; 95% confidence interval, 2.30-5.55). Subjects with RLS had significantly lower quality-of-life scores than those without the syndrome. CONCLUSIONS: Restless legs syndrome is a common disease in the general population, affecting women more often than men. It is associated with reduced quality of life in cross-sectional analysis. Parity is a major factor in explaining the sex difference and may guide further clarification of the etiology of the disease.
Tidsskr Nor Laegeforen. 2004 Jan 8;124(1):25-7. :
[Restless legs]
[Article in Norwegian]
Kinge E, Lossius MI.
Sandvika Nevrologpraksis, 1338 Sandvika.
einar.kinge.sandneur@as.online.no
BACKGROUND: Restless legs syndrome is a common and not fully appreciated disorder. Improved treatment options require knowledge about the condition. MATERIAL AND METHODS: The article is based on a literature search on Medline, PubMed and Scirus for the years 1988-2003 with the keyword "restless legs". RESULTS AND INTERPRETATION: Restless legs syndrome is a chronic condition defined as an irresistible desire to move one's limbs, usually associated with paraesthesia/dysaesthesia and motor restlessness. The symptoms start or worsen at rest and improve with activity. The prevalence is between 5% and 15%. 80% of patients suffer from periodic limb movements in sleep. A current hypothesis is that the condition results from a deficiency of iron that lead to the underlying dopaminergic abnormalities. Therapeutically, studies have confirmed the effect of levodopa and dopamine agonists; dopamine agonists seem to imply less risk of side effects.
CNS Drugs. 2004;18(1):27-36. :
Role of dopamine receptor agonists in the treatment of restless legs syndrome.
Happe S, Trenkwalder C.
Department of Clinical Neurophysiology, University of Gottingen, Gottingen, Germany.
shappe@gwdg.de
The restless legs syndrome (RLS) is defined by four essential criteria obligatory for clinical diagnosis which were established, and recently revised, by the International RLS Study Group. These are (i) the urge to move the legs, usually accompanied or caused by uncomfortable and unpleasant sensations in the legs, which are (ii) worse during rest/inactivity, (iii) partially or totally relieved by movement and (iv) worse at night/in the evening. Treatment with levodopa leads to symptom relief, but augmentation (occurrence of symptoms before levodopa administration in the evening) may occur, limiting the long-term use of this drug. This article gives an overview of the treatment in general and the role of dopamine receptor agonists in the therapy of RLS and periodic limb movements (PLMs). Dopamine receptor agonists are widely used as an effective treatment for RLS and PLMs, presumably because of their longer half-lives, lower likelihood of augmentation and good tolerability compared with levodopa. It was shown that, for example, pergolide, ropinirole, pramipexole and cabergoline alleviated RLS symptoms in 70-90% of patients. A new non-oral (transdermal) formulation of one dopamine receptor agonist, rotigotine, has recently been developed and shown to be efficacious in RLS. Further research should focus on long-term observations and comparisons of different dopamine receptor agonists in RLS.
J Neurol Neurosurg Psychiatry. 2004 Jan;75(1):92-7. :
Ropinirole in the treatment of restless legs syndrome: results from the TREAT RLS 1 study, a 12 week, randomised, placebo controlled study in 10 European countries.
Trenkwalder C, Garcia-Borreguero D, Montagna P, Lainey E, de Weerd AW, Tidswell P, Saletu-Zyhlarz G, Telstad W, Ferini-Strambi L; Therapy with Ropiunirole; Efficacy and Tolerability in RLS 1 Study Group.
Department of Clinical Neurophysiology, Paracelsus-Elena-Klinik, University of Gottingen, Gottingen, Germany.
ctrenkw@gwdg.de
OBJECTIVE: To assess the efficacy, safety, and tolerability of ropinirole in the treatment of patients with restless legs syndrome. METHODS: A 12 week, prospective, double blind, randomised comparison involving 284 patients from 10 European countries. All participants had a score of > or =15 on the international restless legs scale (IRLS). Patients were randomised (1:1) to receive either ropinirole 0.25-4.0 mg once daily or placebo. The primary efficacy end point was mean change from baseline to week 12 in total IRLS score. Global improvements (clinical global impression (CGI) scale) and improvements in sleep, health related quality of life (QoL; using generic and disease specific measures), work, and other activities were also assessed. RESULTS: 112/146 patients (76.7%) taking ropinirole and 109/138 (79.0%) taking placebo completed the study. Improvement in IRLS at week 12 with ropinirole (mean (SD) dose, 1.90 (1.13) mg/day) was greater than with placebo (mean (SE): -11.04 (0.719) v -8.03 (0.738) points; adjusted difference = -3.01 (95% confidence interval (CI), -5.03 to -0.99); p = 0.0036). More patients in the ropinirole group (53.4%) showed improvement on the CGI scale at week 12 than in the placebo group (40.9%; adjusted odds ratio = 1.7 (1.02 to 2.69); p = 0.0416). Significant differences on both IRLS and CGI scales favouring ropinirole were apparent by week 1. Ropinirole was also associated with significantly greater improvements in sleep and QoL end points. The most common adverse events were nausea and headache. CONCLUSIONS: Ropinirole improves restless legs syndrome compared with placebo, with benefits apparent by week 1. It is generally well tolerated
Neurology. 2003 Dec 9;61(11):1562-9. :
Unexpectedly low prevalence and unusual characteristics of RLS in Mersin, Turkey.
Sevim S, Dogu O, Camdeviren H, Bugdayci R, Sasmaz T, Kaleagasi H, Aral M, Helvaci I.
Department of Neurology, Faculty of Medicine, Mersin University, Turkey.
serhansevim@mail.koc.net
OBJECTIVE: To determine the prevalence, risk factors, and clinical presentation of restless legs syndrome (RLS) in a Turkish population. METHODS: A face-to-face, population-based epidemiologic survey was conducted. Multistep, stratified, cluster, and systematic samplings were used. A total of 3,234 adults were interviewed. RESULTS: Of the 3,234 participants, 103 (3.19%) experienced RLS. This prevalence rate is lower than those of other epidemiologic studies conducted among European and North American populations. RLS was found to be more common among women, cigarette smokers, and individuals residing in high altitudes. The self-reported mental and general health status of patients was worse than in the control subjects. The prevalence of RLS did not differ by age or body mass index. CONCLUSION: The discrepancy in RLS prevalence studies (including the authors') suggests that prevalence varies among different races, thus supporting a genetic predisposition.
: J Neurol. 2003 Dec;250(12):1494-5. :
Pramipexole in Restless Legs syndrome. Evaluation by suggested immobilization test.
Manconi M, Casetta I, Govoni V, Cesnik E, Ferini-Strambi L, Granieri E.
Publication Types:
Letter
Drug Ther Bull. 2003 Nov;41(11):81-3. :
Managing patients with restless legs.
[No authors listed]
Estimates suggest that around 10-15% of adults have restless legs, or Ekbom syndrome. This condition is characterised by a range of uncomfortable and sometimes distressing motor and sensory symptoms during quiet wakefulness and/or sleep, such as feelings of burning, tickling or crawling, pain, cramping, numbness or weakness in the lower limbs, and, sometimes, also in the trunk and arms. The problem can seriously affect quality of life, yet is frequently dismissed as trivial. Often, it is unrecognised, incorrectly regarded as a neurosis, or managed poorly or not at all. Here we review how people with restless legs can best be helped.
Sleep. 2003 Nov 1;26(7):815-8. :
Cabergoline is an effective single-drug treatment for restless legs syndrome: clinical and actigraphic evaluation.
Zucconi M, Oldani A, Castronovo C, Ferini-Strambi L.
Sleep Disorders Center, Department of Neurology, H San Raffaele Scientific Institute and Hospital, Universita Vita-Salute San Raffaele, Milan, Italy.
zucconi.marco@hsr.it
OBJECTIVES: To evaluate the efficacy and the safety of cabergoline, a dopamine-receptor agonist with a long half-life, in restless legs syndrome (RLS). DESIGN: A 2 month, single blind, open labeled clinical trial. Patients were evaluated with polysomnography at baseline (B), following 1 week of placebo (T0), and after 1 week (T1) and 2 months (T2) of cabergoline treatment. The clinical global impression was assessed using International RLS Study Group Rating Scale and nocturnal actigraphy. SETTING: Sleep Disorders Center. PATIENTS: Twelve patients with moderate to severe RLS (mean age 56.6 years) who were naive to treatment with dopaminergic agents. INTERVENTIONS: Upward titration of cabergoline (from 0.5 mg to 2 mg) in a single evening dose. MEASUREMENTS AND RESULTS: Ten patients completed the study (mean dose, 1.1 mg), and all showed an improvement of RLS symptoms. The results from the International RLS Study Group Rating Scale showed similarities between B (24.3+/-2.9) and T0 (23.1+/-5.9; P=0.6), with significant improvement at T1 (12.5+/-6.0; P=0.01 vs B and T0) and T2 (9.8+/-6.9; P=0.001 vs B and P=0.005 vs T0). The mean nocturnal activity value measured by actigraphy during week 1 decreased from T0 (19.8+/-9.3) to T1 (13.6+/-6.4) and dropped significantly at T2 (8.5+/-5.3; P=0.05). Nine patients continued the treatment up to 12 months with consistent efficacy, few side effects, and no augmentation. CONCLUSIONS: Low doses of cabergoline showed effectiveness and safety in patients with moderate to severe RLS, with no appearance of augmentation phenomenon. Double blind, crossover, polysomnographic studies are necessary to confirm this preliminary data.
Sleep. 2003 Nov 1;26(7):819-21. :
Pramipexole in the management of restless legs syndrome: an extended study.
Silber MH, Girish M, Izurieta R.
Sleep Disorders Center, Mayo Clinic, Rochester, MN 55905, USA.
msilber@mayo.edu
STUDY OBJECTIVES: To determine whether pramipexole used over an extended time for restless legs syndrome (RLS) remains effective; whether the dose of the drug needs to be increased; whether augmentation develops; and whether side effects, especially sleepiness, are prominent. DESIGN: Retrospective review of the records of consecutive patients treated with pramipexole for RLS. SETTING: Sleep disorders center in an academic hospital. PATIENTS: 60 consecutive patients treated with pramipexole for RLS. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: Pramipexole was completely effective in controlling RLS in 67%, partially effective in 27%, and ineffective in 7% of patients. Eleven patients (18%) discontinued pramipexole after less than 4 months; the remainder were followed for a mean of 27.2 months, during which only 4 others stopped the drug. The median daily dose increased from 0.38 mg after stabilization to 0.63 mg at the end of the study. Forty percent experienced mild side effects, most commonly insomnia, nausea or dyspepsia, and dizziness. Only 5% experienced sleepiness, and none experienced sleep attacks while driving. Augmentation developed in 33%, most in the first year and all by 30 months. Augmentation was not predictable by prior augmentation with other dopaminergic agents. Only 1 patient discontinued pramipexole because of augmentation. CONCLUSIONS: Pramipexole was effective for RLS with continued response with time. Modest escalations in dose occurred, partly due to additional doses prescribed for augmentation. Side effects were common, but generally mild and tolerated. Sleepiness while driving was not a problem. Augmentation occurred in 33% of patients but was treatable with increased doses earlier in the day.
Expert Opin Pharmacother. 2003 Oct;4(10):1727-38. :
Current treatment options for restless legs syndrome.
Wetter TC, Winkelmann J, Eisensehr I.
Max Planck Institute of Psychiatry, Kraepelinstrasse 10, D-80804 Munich, Germany.
wetter@mpipsykl.mpg.de
Restless legs syndrome (RLS) is a common but often underdiagnosed neurological disorder characterised by an imperative desire to move the extremities associated with paraesthesias, motor restlessness, worsening of symptoms at rest in the evening or at night and, as a consequence, sleep disturbances particulary. Additionally, most patients with RLS have periodic limb movements during sleep and relaxed wakefulness. The aetiology of RLS remains unknown. Treatment of RLS is generally symptomatic, a causal therapy is possible only in the secondary forms. Dopaminergic agents including levodopa and dopamine agonists such as pergolide, pramipexole, cabergoline and ropinirole are regarded as the treatment of choice for idiopathic RLS, however, the development of augmentation of symptoms, especially under levodopa therapy, may be a major problem. Except in special circumstances, opioids and anticonvulsants such as gabapentin or benzodiazepines, are regarded as second-line treatment. In secondary RLS, the underlying illness should first be treated, although dopaminergic drugs may also be helpful.
Arch Intern Med. 2003 Oct 27;163(19):2323-9. :
Restless legs syndrome symptoms in primary care: a prevalence study.
Nichols DA, Allen RP, Grauke JH, Brown JB, Rice ML, Hyde PR, Dement WC, Kushida CA.
Stanford University Center of Excellence for Sleep Disorders, Stanford, CA 94304, USA.
BACKGROUND: There are relatively few studies on the prevalence of restless legs syndrome (RLS) in the general population, even fewer that used diagnostic questions covering all 4 essential diagnostic criteria defining the RLS symptom complex, and none that have reported on the 2 RLS phenotypes for patients seen by family physicians. METHODS: To determine the prevalence of the symptom complex, diagnostic for RLS in a primary care patient population, a prospective population-based single-center study was performed. Every adult patient presenting for care in a small rural primary care practice with mostly white patients was surveyed for a 1-year period using a validated RLS diagnostic questionnaire. RESULTS: A total of 2099 patients completed the questionnaire. Analysis revealed that 24.0% of these patients were positive for all 4 of the essential symptoms used to make the diagnosis of RLS and 15.3% reported these symptoms at least weekly. In addition, the RLS symptom complex was reported significantly more often by women than men and, as a whole, patients reporting the RLS symptoms were significantly older than patients without symptoms. The prevalence of symptoms increased with age until about 60 years and then showed a steady decrease thereafter. Further, early-onset RLS was significantly more common in women than men. CONCLUSIONS: A high prevalence of RLS symptoms was observed in this primary care population. This finding supports the need for heightened awareness in both the medical community and general population regarding this disorder, which can often be effectively treated within the primary care practice.
Mov Disord. 2003 Oct;18(10):1184-9. :
One-year treatment with standard and sustained-release levodopa: appropriate long-term treatment of restless legs syndrome?
Trenkwalder C, Collado Seidel V, Kazenwadel J, Wetter TC, Oertel W, Selzer R, Kohnen R.
Max Planck Institute of Psychiatry, Munich, Germany.
ctrenkw@gwdg.de
To investigate the long-term efficacy and safety of sustained-release (SR) in combination with regular-release (RR) levodopa/benserazide in the treatment of restless legs syndrome (RLS), an open-label, prospective, extension study of a preceding double-blind crossover trial was performed for 12 months. Twenty-three severely disturbed RLS patients (7 men, 16 women) received a combination of RR and SR levodopa. Patients were treated on average for 10 months with a mean daily dose of 203 +/- 101 mg of RR and of 185 +/- 93 mg of SR levodopa. The mean daily total dose was 388 +/- 162 mg levodopa. Efficacy was documented using patient's rating scales, sleep diaries, and investigator's global ratings with the Clinical Global Impressions (CGI). Ten of 23 patients completed the 1-year extension. Between baseline of the crossover trial and endpoint of the extension study (last-observation-carried-forward method, intention-to-treat population), quality of sleep improved (+3.5 +/- 1.9, 7-point scale), sleep latency was shortened (-131 +/- 152 minutes), and total sleep time lengthened (+ 190 +/- 136 minutes). Severity of RLS at time of falling asleep (-6.5 +/- 3.4, 11-point scale) and during the night (-6.0 +/- 3.5) was markedly lower at the end of the extension but severity of RLS during the day (+1.9 +/- 5.0) slightly increased. Of 13 dropouts, 8 patients discontinued therapy because of worsening RLS during the day. This trial shows that long-term treatment with the combination of RR and SR levodopa/benserazide in RLS patients with late-night problems was efficacious and not limited by tolerability problems in 40% of patients, whereas in the majority of patients, aggravating daytime problems required termination of the levodopa therapy within the 1-year treatment period. Copyright 2003
Neurology. 2003 Sep 23;61(6 Suppl 3):S49-55. :
Restless legs syndrome and PD: a review of the evidence for a possible association.
Garcia-Borreguero D, Odin P, Serrano C.
Department of Neurology, Fundacion Jimenez Diaz, Universidad Autonoma de Madrid, Madrid, Spain.
Restless legs syndrome (RLS) is a common neurologic disorder whose prevalence has been estimated at 4 to 10% of the general population. Although its pathophysiology remains unknown, dopaminergic mechanisms are believed to play a central role. Furthermore, dopaminergic drugs have shown therapeutic efficacy in various large-scale therapeutic trials, and dopamine agonists now represent the first line of treatment. Several studies performed over the past years have suggested an association between RLS and Parkinson's disease (PD). However, the evidence is still limited and large controlled studies are needed to show the prevalence rates of PD in RLS patients versus controls. Furthermore, in contrast to PD, some brain imaging studies have revealed a mild striatal dysfunction in RLS. Preliminary neuropathologic evidence also suggests that the dopaminergic dysfunction does not involve neuronal degeneration at that level. Therefore, neuronal degeneration in other dopaminergic pathways than the nigrostriatal might be relevant in the pathogenesis of RLS in PD.
Sleep. 2003 Sep15;26(6):673-7. :
The prevalence of restless legs syndrome among pregnant women in Japan and the relationship between restless legs syndrome and sleep problems.
Suzuki K, Ohida T, Sone T, Takemura S, Yokoyama E, Miyake T, Harano S, Motojima S, Suga M, Ibuka E.
Department of Public Health, School of Medicine, Nihon University, Tokyo, Japan.
qwu00740@nifty.ne.jp
STUDY OBJECTIVES: To clarify the prevalence of restless legs syndrome (RLS) in pregnant women living in Japan and to analyze the relationship between sleep problems and RLS, in order to discuss ways for pregnant women to obtain comfortable sleep and to improve the health of both the mother and child. DESIGN: A cross-sectional questionnaire survey. SETTING: 500 clinical institutions with maternity services were randomly sampled from a list of organizations identified in a survey by the Japan Association of Obstetricians and Gynecologists. Of these 500 institutions, 260 participated in the survey. PARTICIPANTS: 16,528 pregnant women living in Japan. INTERVENTIONS: N/A. MEASUREMENTS AND RESULTS: In this survey of pregnant women, the prevalence of RLS was found to be 19.9%. An analysis was conducted on the relationship between RLS and other factors such as subjective evaluation of sleep, difficulty initiating sleep, difficulty maintaining sleep, early morning awaking, and excessive daytime sleepiness. The result of this analysis suggested that women with these sleep-related problems were more likely to have RLS than those without. In addition, RLS was more prevalent in the later stages of pregnancy. CONCLUSION: In the pregnant women in our survey, the prevalence of RLS was found to be 19.9%, which is higher than the prevalence of RLS that has been found in the general public in a previous study. This suggests that RLS-related sleep problems may be an important public health issue among pregnant women in Japan. This finding may have implications for attempts to improve sleep hygiene in this group.
Neurology. 2003 Aug 12;61(3):304-9. :
Neuropathological examination suggests impaired brain iron acquisition in restless legs syndrome.
Connor JR, Boyer PJ, Menzies SL, Dellinger B, Allen RP, Ondo WG, Earley CJ.
Department of Neuroscience & Anatomy, Penn State University College of Medicine, M.S. Hershey Medical Center, Hershey, PA 17033, USA.
jrc3@psu.edu
OBJECTIVE: To assess neuropathology in individuals with restless legs syndrome (RLS). METHODS: A standard neuropathologic evaluation was performed on seven brains from individuals who had been diagnosed with RLS. The substantia nigra was examined in greater detail for iron staining and with immunohistochemistry for tyrosine hydroxylase and proteins involved in iron management. Five age-matched individuals with no neurologic history served as controls. RESULTS: There were no histopathologic abnormalities unique to the RLS brains. Tyrosine hydroxylase staining in the major dopaminergic regions appeared normal in the RLS brains. Iron staining and H-ferritin staining was markedly decreased in the RLS substantia nigra. Although H-ferritin was minimally detected in the RLS brain, L-ferritin staining was strong. However, the cells staining for L-ferritin in RLS brains were morphologically distinct from those in the control brains. Transferrin receptor staining on neuromelanin-containing cells was decreased in the RLS brains compared to normal, whereas transferrin staining in these cells was increased. CONCLUSIONS: RLS may not be rooted in pathologies associated with traditional neurodegenerative processes but may be a functional disorder resulting from impaired iron acquisition by the neuromelanin cells in RLS. The underlying mechanism may be a defect in regulation of the transferrin receptors
Biomed Tech (Berl). 2003 Mar;48(3):62-7. :
Movement disorders in sleep: Parkinson's disease and restless legs syndrome.
Happe S, Trenkwalder C.
Department of Clinical Neurophysiology, University of Gottingen, Germany.
In recent years, sleep abnormalities have increasingly been observed in patients with movement disorders. During sleep, most patients with Parkinson's disease also exhibit the movements characteristically seen during the wake period. Movement activity during sleep may impair sleep quality and lead to daytime sleepiness and reduced quality of life. Disordered REM sleep with enhanced muscle tone is common in patients with neurodegenerative disease, and may precede the clinically evident symptoms of Parkinson's disease by years. Sleep disorders in patients with Parkinson's disease are common, and require the application of individual treatment strategies. A further frequent disorder primarily classified as a sleep disorder (dyssomnia) is the restless legs syndrome (RLS), which is closely related to the nocturnal periodic limb movement disorder and affects up to 15% of the population. The present review focuses on nocturnal motor activity and sleep in Parkinson's disease and RLS.
Sleep Med. 2003 Mar;4(2):101-19. :
Restless legs syndrome: diagnostic criteria, special considerations, and epidemiology. A report from the restless legs syndrome diagnosis and epidemiology workshop at the National Institutes of Health.
Allen RP, Picchietti D, Hening WA, Trenkwalder C, Walters AS, Montplaisi J; Restless Legs Syndrome Diagnosis and Epidemiology workshop at the National Institutes of Health; International Restless Legs Syndrome Study Group.
Department of Neurology, Sleep Medicine, Johns Hopkins Bayview Medical Center, Asthma and Allergy Building 1B46b, 5501 Hopkins Bayview Circle, Baltimore, MD 21224, USA.
richardjhu@aol.com
BACKGROUND: Restless legs syndrome is a common yet frequently undiagnosed sensorimotor disorder. In 1995, the International Restless Legs Syndrome Study Group developed standardized criteria for the diagnosis of restless legs syndrome. Since that time, additional scientific scrutiny and clinical experience have led to a better understanding of the condition. Modification of the criteria is now necessary to better reflect that increased body of knowledge, as well as to clarify slight confusion with the wording of the original criteria. SETTING: The restless legs syndrome diagnostic criteria and epidemiology workshop at the National Institutes of Health. PARTICIPANTS: Members of the International Restless Legs Syndrome Study Group and authorities on epidemiology and the design of questionnaires and scales. OBJECTIVE: To modify the current criteria for the diagnosis of restless legs syndrome, to develop new criteria for the diagnosis of restless legs syndrome in the cognitively impaired elderly and in children, to create standardized criteria for the identification of augmentation, and to establish consistent questions for use in epidemiology studies. RESULTS: The essential diagnostic criteria for restless legs syndrome were developed and approved by workshop participants and the executive committee of the International Restless Legs Syndrome Study Group. Criteria were also developed and approved for the additional aforementioned groups.
Sleep Med. 2003 Mar;4(2):133-5. :
Factor analysis of the International Restless Legs Syndrome Study Group's scale for restless legs severity.
Allen RP, Kushida CA, Atkinson MJ; RLS QoL Consortium.
Department of Neurology and Sleep Medicine, Johns Hopkins University, Baltimore, MD, USA.
richardjhu@aol.com
OBJECTIVE: The International Restless Legs Syndrome Study Group has developed and validated a ten-item scale for assessing the severity of the restless legs syndrome. This International Restless Legs Severity Scale (IRLS) is reported to have a high degree of internal consistency and it has generally been used as a single scale. This study uses a factor analytic approach to evaluate the IRLS for possibly useful subscales. METHODS: A large convenience sample (n=516) of self-identified restless leg syndrome patients completed the IRLS over the Internet. Data were analyzed using principal component analyses. RESULTS: Two primary factors were identified, one with six items related to symptom severity and a second with three items related to impact of the symptoms on life. These accounted for 41.8 and 22.5% of the variance, respectively. CONCLUSIONS: The IRLS can be evaluated using separate subscale scores: one for symptoms and the other symptom impact. The relative merits of these subscale scores versus the score for the entire test need to be evaluated in different situations in further studies, in especially the ones involving assessing responsiveness to treatment effects.
