Efficacy of gabapentin enacarbil in adult patients with severe primary restless legs syndrome

AimAssess efficacy and tolerability of gabapentin enacarbil (GEn) in adults with severe primary restless legs syndrome (RLS).MethodsWe pooled data from three 12-week, double-blind, placebo-controlled, randomized trials (NCT00298623, NCT00365352, NCT01332305) across GEn 600-mg, GEn 1200-mg, and placebo treatment groups for severe primary RLS (baseline International Restless Legs Scale (IRLS) total score ≥24). Co-primary end points at week 12 were mean change from baseline in IRLS total score and proportion of responders (“much”/very much” improved) on the investigator-rated Clinical Global Impression – Improvement (CGI-I) Scale. Outcomes for individual IRLS items (eg, sleep, mood, quality of life, pain, safety) were assessed.ResultsA total of 309 patients had severe primary RLS (placebo, n = 110; GEn 600 mg, n = 80; GEn 1200 mg, n = 119). GEn 600 mg and 1200 mg significantly improved least-squares mean IRLS total scores versus placebo at week 12 (placebo, −12.3; GEn 600 mg, −16.3; GEn 1200 mg, −18.0; treatment difference vs. placebo, both p <0.01). Significantly more patients with severe primary RLS treated with GEn 600 mg (64%) and 1200 mg (74%) were CGI-I responders at week 12 versus placebo (42%; p <0.01 for both GEn doses). Both GEn doses led to significant improvements in the other outcomes explored versus placebo at week 12. The most frequent treatment-emergent adverse events (TEAEs) were somnolence (GEn, 21–24%; placebo, 3%) and dizziness (GEn, 14–19%; placebo, 3%).ConclusionsGEn (600 mg or 1200 mg) once daily significantly improved RLS symptoms and consequences of these symptoms in severe primary RLS. The most frequent TEAEs were somnolence and dizziness.     

Effect of pramipexole on RLS symptoms and sleep: a randomized, double-blind, placebo-controlled trial

BackgroundPatients with Restless Legs Syndrome (RLS) often seek treatment because of sleep problems related to nocturnal symptoms. Our goal was to test the ability of pramipexole to improve sleep in RLS patients and to reconfirm its efficacy for primary RLS symptoms.MethodsAdults with moderate or severe RLS were randomized to receive placebo or pramipexole (flexibly titrated from 0.25 to 0.75 mg), 2–3 h before bedtime for 12 weeks. The co-primary outcome measures were change in Medical Outcomes Study (MOS) sleep disturbance score and International RLS Study Group Rating Scale (IRLS) score at 12 weeks.ResultsThe intent-to-treat population included 357 patients: 178 received pramipexole and 179 received placebo. At 12 weeks, the adjusted mean change from baseline was greater for pramipexole (vs. placebo) for IRLS score (−13.4 ± 0.7 vs. −9.6 ± 0.7) and MOS sleep disturbance score (−25.3 ± 1.5 vs. −16.8 ± 1.5) (p ⩽ 0.0001; ANCOVA). Responder rates (clinical and patient global impression and IRLS) were also significantly higher in the pramipexole group. RLS-QOL score was improved over placebo at Week 12 (p < 0.01) as were MOS sleep adequacy (p = 0.0008) and quantity (p = 0.08) scores. Nine percent of patients in each group withdrew because of adverse events.ConclusionsPramipexole is effective and well-tolerated for RLS and related sleep disturbance.     

A method to switch from oral dopamine agonists to rotigotine in patients with restless legs syndrome and mild augmentation

BackgroundWe examined the short- and long-term efficacy and tolerability of a cross-titration algorithm from oral dopamine agonists to the rotigotine transdermal patch in patients dissatisfied with their restless legs syndrome (RLS) treatment, predominantly with mild augmentation.MethodsPatients with RLS (n = 20) were recruited at a single site. The cross-titration consisted of decreasing oral dopaminergic agents (ropinirole by 1 mg or pramipexole by 0.25 mg) and increasing rotigotine by 1 mg every two days. Efficacy and adverse events (AEs) were assessed at one, three, six and 12 months after the switch.ResultsPatients had moderate–severe RLS symptoms at the baseline (mean international restless legs syndrome (IRLS) score 19.4 ± 5.5); 85% had augmentation and 45% reported afternoon RLS symptoms. The baseline mean pramipexole equivalent dose was 0.6 ± 0.3 mg. At Week 5, 85% (17/20) had successfully switched from their oral dopamine agonist to rotigotine (mean dose 2.5 ± 0.6 mg; change in IRLS score: −6.7 ± 8.4, p = 0.002); 14 patients were CGI-I responders (much or very much improved). Three patients withdrew due to lack of efficacy. Twelve months after cross-titration, 10 patients continued on rotigotine, of whom four required either higher doses of rotigotine or supplemental RLS medication compared with their optimal Week 5 dose; five patients withdrew due to AEs and two due to lack of efficacy.ConclusionA cross-titration to rotigotine was efficacious after five weeks in 70% of patients dissatisfied with RLS treatment, most of whom had mild augmentation. At one year following the medication switch, 50% had discontinued rotigotine due to lack of continued efficacy or side effects.     

Randomized,placebo-controlled trial of ferric carboxymaltose in restless legs syndrome patients with iron deficiency anemia

ObjectiveIntravenous ferric carboxymaltose (FCM) has been shown to be efficacious in treating restless legs syndrome (RLS) symptoms in non-anemic patients. The aim of this study was to evaluate the effectiveness of FCM in treating RLS symptoms in patients who also had an iron deficiency anemia (IDA).MethodsThis is a randomized, double-blinded, placebo-controlled study. Subjects with RLS and IDA were enrolled. Subjects received an infusion of either 1500 mg FCM or placebo in Phase I. The primary outcomes were a change-from-baseline at week six on the International Restless Legs Syndrome Study Group scale (IRLS). Phase II of the study involved long-term (52 weeks) follow-up, for those who responded to treatment in the prior phase, with the potential for further treatment if symptoms returned.ResultsWe enrolled 29 RLS patients with IDA (15 FCM and 14 placebo). At week six post-infusion, FCM compared to placebo group showed significant improvement from baseline in IRLS score (−13.47 ± 7.38 vs. 1.36 ± 3.59). Among secondary outcome variables, quality of sleep showed significant improvement from baseline in the FCM group. 61% of subjects remained off RLS medications at the Phase II, week-52 endpoint. There were no serious adverse events observed in the study.ConclusionThe study showed significant efficacy and safety of FCM 1500 mg treatment both in the short term (6 weeks) and long term (52 weeks) in RLS patients with IDA.     

Noninvasive Vagus Nerve Stimulation: A New Therapeutic Approach for Pharmacoresistant Restless Legs Syndrome

AimsThis work aimed to study the effect of noninvasive vagus nerve stimulation on severe restless legs syndrome (RLS) resistant to pharmacotherapy.Materials and MethodsPatients with severe pharmacoresistant RLS were recruited from a tertiary care sleep center. Intervention was one-hour weekly sessions of transauricular vagus nerve stimulation (tVNS) in the left cymba concha, for eight weeks. The primary outcome measure was the score on the International Restless Legs Rating Scale (IRLS); secondary outcome measures were quality of life (Restless Legs Syndrome Quality of Life scale [RLSQOL]), mood disorders using the Hospital Anxiety and Depression scale subscale for depression (HADD) and Hospital Anxiety and Depression scale subscale for anxiety (HADA), and objective sleep latency, sleep duration, efficiency, and leg movement time measured by actigraphy.ResultsFifteen patients, 53% male, aged mean 62.7 ± 12.3 years with severe RLS, reduced quality of life, and symptoms of anxiety and depression, were included. The IRLS improved from baseline to session eight: IRLS 31.9 ± 2.9 vs 24.6 ± 5.9 p = 0.0003. Of these participants, 27% (4/15) had a total response with a decrease below an IRLS score of 20; 40% (6/15) a partial response with an improvement in the IRLS > 5 but an IRLS above 20; and 33% (5/15) were nonresponders. After tVNS, quality of life improved (RLSQOL 49.3 ± 18.1 vs 80.0 ± 19.6 p = 0.0005), as did anxiety (HADA 8.9 ± 5.4 vs 6.2 ± 5.0 p = 0.001) and depression (HADD 5.2 ± 4.5 vs 4.0 ± 4.0 p = 0.01). No significant change was found in actigraphic outcome measures.ConclusionsIn this pilot study, tVNS improved the symptoms of RLS in 66% of participants (10/15) with severe pharmacoresistant RLS, with concomitant improvements in quality of life and mood. Randomized controlled trials evaluating therapeutic efficacy of tVNS in RLS are needed to confirm these promising findings.     

Open-label study of the efficacy and safety of intravenous ferric carboxymaltose in pregnant women with restless legs syndrome

ObjectiveThe objective of this study was to test the efficacy and safety of intravenous ferric carboxymaltose (FCM) in pregnant women with restless legs syndrome (RLS) and iron deficiency or anemia. The open-label pilot study (exploratory) was performed at the University Hospital of Zürich and the Neurocenter of Southern Switzerland (Lugano).Patient and MethodsNineteen women in the third trimester of pregnancy with moderate-to-severe RLS and serum ferritin levels <35 µg/l or hemoglobin (Hb) < 11.0 g/dl were included in the study. RLS was graded according to the International Restless Legs Syndrome (IRLS) Study Group rating scale. All participants had a score of ≥20 or had RLS ≥3 times/week. Based on the Hb levels, 500 or 700 mg of FCM was administered over 20 min. The primary end point was a ≥ 50% reduction in the mean IRLS score one week after FCM infusion. The secondary end points included periodic limb movements (PLMs; assessed using nocturnal foot actigraphy), sleep quality (assessed using the Pittsburgh Sleep Quality Index), and safety.ResultsThe IRLS score decreased from 23 ± 7 (baseline) to 13 ± 7 (P <0.01), whereas the PLM index decreased from 35 ± 26 (baseline) to 25 ± 20 (P <0.001). Significant improvement in sleep quality was also reported (P <0.029), and treatment was well tolerated. Three serious adverse events were reported, but they were considered unrelated to treatment.ConclusionsThese data provide promising evidence on the safety and efficacy of FCM for moderate-to-severe RLS in pregnant women with iron deficiency or anemia. Therefore, a future placebo-controlled study is warranted.     

Efficacy and safety of pramipexole in restless legs syndrome

OBJECTIVE: To evaluate the efficacy and safety of pramipexole in patients with moderate to severe restless legs syndrome (RLS) METHODS: The authors conducted a 12-week, double-blind, randomized, placebo-controlled trial of fixed doses of pramipexole (0.25, 0.50, and 0.75 mg/day). Patients (N = 344) were up-titrated to their randomized dose over 3 weeks. The primary efficacy endpoints were patient ratings of symptom severity on the International RLS Study Group Rating Scale (IRLS) and clinician ratings of improvement on the Clinical Global Impressions-Improvement (CGI-I) scale. Secondary efficacy endpoints included visual analogue ratings of sleep and quality of life (QOL) RESULTS: By both primary measures, pramipexole was superior to placebo. For IRLS, the adjusted mean (SE) change from baseline to week 12 was -9.3 (1.0) for placebo, -12.8 (1.0) for 0.25 mg/day, -13.8 (1.0) for 0.50 mg/day, and -14.0 (1.0) for 0.75 mg/day (all p < 0.01). Similarly, pramipexole increased the percentage of patients with a CGI-I rating of "very much improved" or "much improved" at the end of the trial (51.2% for placebo and 74.7%, 67.9%, and 72.9% for pramipexole; all p < 0.05). Pramipexole significantly improved ratings of symptom severity, day and night, and also ratings of sleep satisfaction and QOL. Pramipexole was well tolerated: The most frequent adverse events with higher occurrence in the pramipexole group were nausea (19.0% vs 4.7%) and somnolence (10.1% vs 4.7%) CONCLUSION: As rated by patients and by clinicians, pramipexole was efficacious and safe in reducing the symptoms of restless legs syndrome.     

A randomized,double-blind, 6-week,dose-ranging study of pregabalin in patients with restless legs syndrome

ObjectiveThis study evaluated the dose-related efficacy and safety of pregabalin in patients with idiopathic restless legs syndrome (RLS).MethodsThis six-arm, double-blind, placebo-controlled, dose–response study randomized patients (N = 137) with moderate-to-severe idiopathic RLS in an equal ratio to placebo or pregabalin 50, 100, 150, 300, or 450 mg/day. The dose–response was characterized using an exponential decay model, which estimates the maximal effect (E_max) for the primary endpoint, the change in the International Restless Legs Study Group Rating Scale (IRLS) total score from baseline to week 6 of treatment. Secondary outcomes included Clinical Global Impressions-Improvement Scale (CGI-I) responders, sleep assessments, and safety.ResultsThe separation of treatment effect between placebo and pregabalin began to emerge starting at week 1 which continued and increased through week 6 for all dose groups. The IRLS total score for pregabalin was dose dependent and well characterized for change from baseline at week 6. The model estimated 50% (ED₅₀) and 90% (ED₉₀) of the maximal effect in reducing RLS symptoms that occurred at pregabalin doses of 37.3 and 123.9 mg/day, respectively. A higher proportion of CGI-I responders was observed at the two highest doses of pregabalin (300 and 450 mg/day) versus placebo. Dizziness and somnolence were the most common adverse events and appeared to be dose-related.ConclusionsIn this 6-week phase 2b study, pregabalin reduced RLS symptoms in patients with moderate-to-severe idiopathic RLS. The symptom reduction at week 6 was dose-dependent with 123.9 mg/day providing 90% efficacy. Pregabalin was safe and well tolerated across the entire dosing range.     

Efficacy of pramipexole in restless legs syndrome: a six-week, multicenter, randomized, double-blind study (effect-RLS study).

We evaluated the efficacy of pramipexole versus placebo in restless legs syndrome (RLS) for 6 weeks. Overall, 345 patients were randomly assigned in a 1:2 ratio to receive either placebo (n = 115) or pramipexole (n = 230) with a starting dose of 0.125 mg/day. The dose was individually optimized according to the Patient Global Impression (PGI) assessment, up to a maximum of 0.75 mg/day. The primary endpoint consisted of two assessments: the change from baseline in the International RLS Study Group Rating Scale (IRLS) and the proportion of patients with Clinical Global Impressions-Improvement (CGI-I) assessments of "much/very much improved" (CGI-I responders) at week 6. Secondary endpoints included PGI and IRLS responder rates. Patient demographics and baseline characteristics were comparable between treatment groups. At baseline, mean IRLS scores were 24.9 (placebo) and 24.7 (pramipexole), representing severely affected patients. After 6 weeks, adjusted mean reductions (+/-SE) in IRLS score were 5.7 (+/-0.9) for placebo (median dose 0.47 mg/day) and 12.3 (+/-0.6) for pramipexole (median dose 0.35 mg/day; P < 0.0001). CGI-I responder rates were 32.5% (placebo) and 62.9% (pramipexole) (P < 0.0001). For all secondary endpoints, pramipexole showed superior results. Pramipexole was well tolerated throughout the study.     

Ropinirole is effective in the treatment of restless legs syndrome. TREAT RLS 2: a 12-week, double-blind, randomized, parallel-group, placebo-controlled study.

Restless legs syndrome (RLS) is a neurological condition with significant impact on sleep and quality of life (QoL). This double-blind, randomized, 12-week, multinational study compared the efficacy and safety of ropinirole and placebo in RLS. In total, 267 outpatients with moderate-to-severe RLS were randomly assigned to ropinirole (0.25-4.0 mg/day) or placebo, 1 to 3 hours before bedtime. The primary endpoint was the change in International Restless Legs Scale (IRLS) score at week 12. Key secondary endpoints were the percentage of patients showing significant improvement on the Clinical Global Impression-Improvement (CGI-I) scale at week 12 and changes in IRLS and CGI-I scale scores at week 1. Other measures included the Medical Outcomes Study sleep scale and Restless Legs Syndrome Quality of Life questionnaire. Improvements were significantly greater for ropinirole than placebo for change in IRLS score at week 12 (-11.2 [SE 0.76] vs. -8.7 [0.75], respectively; adjusted treatment difference -2.5 [95% confidence interval [CI], -4.6, -0.4], P = 0.0197); all key secondary endpoints; sleep and QoL parameters. Adverse events were typical for dopamine agonists; disease augmentation, although not directly assessed, was not reported during treatment. Ropinirole improves symptoms, associated sleep disturbance, and QoL of RLS patients and is generally well tolerated.     

Efficacy of oral iron in patients with restless legs syndrome and a low-normal ferritin: A randomized, double-blind, placebo-controlled study

Background and PurposeRestless Legs Syndrome (RLS) is a primary disorder of sensation that affects sleep and has been associated with iron deficiency. The purpose of this study was to determine if symptomatic RLS patients with low-normal serum ferritin levels benefit from oral iron replacement.Patients and MethodsThis was a randomized, placebo-controlled, double-blinded study. Eligible patients were randomized to oral iron therapy vs. appearance-matched placebo and followed over a 12 week period.ResultsBaseline International Restless Leg Scale (IRLS) scores for the treatment (24.8 ± 5.72) and placebo (23.0 ± 5.03) groups were similar. Baseline ferritin levels for the treatment (40.6 ± 15.3 ng/ml) and placebo (36.7 ± 20.8 ng/ml) groups were also similar. After 12 weeks, IRLS scores decreased more in the treatment arm (10.3 ± 7.40) than in the placebo arm (1.14 ± 5.64), (p = 0.01). Ferritin levels increased more in the treatment arm (25.1 ± 20.3 ng/ml) than in the placebo arm (7.5 ± 13.7 ng/ml), (p = 0.04). We observed a nonsignificant trend toward improved quality of life in the treated patients, (p = 0.07).ConclusionsThis is the first double-blinded, placebo-controlled study to demonstrate statistically significant improvement in RLS symptoms using oral iron therapy in patients with low-normal ferritin. The findings from this study suggest that additional larger randomized placebo-controlled trials of iron as treatment for patients with low-normal ferritin are warranted.     

Relation of the International Restless Legs Syndrome Study Group rating scale with the Clinical Global Impression severity scale,the restless legs syndrome 6-item questionnaire,and the restless legs syndrome-quality of life questionnaire

BackgroundThe SP790 study (ClinicalTrials.gov, NCT00136045) showed benefits of rotigotine over placebo in improving symptom severity of restless legs syndrome (RLS), also known as Willis-Ekbom disease, on the International Restless Legs Syndrome Study Group rating scale (IRLS), Clinical Global Impression item 1 (CGI-1), RLS 6-item questionnaire (RLS-6), and the RLS-quality of life questionnaire (RLS-QoL) in patients with moderate to severe idiopathic RLS. To provide clinical context for the IRLS and to guide the choice of assessment scales for RLS studies, our post hoc analysis of SP790 data evaluated associations between the IRLS and the CGI-1, IRLS and RLS-6, and the IRLS and RLS-QoL.MethodsScale associations were analyzed at baseline and at the end of maintenance (EoM) using data from the safety set (rotigotine and placebo groups combined [n = 458]). Changes from baseline to EoM in IRLS score vs comparator scale scores also were analyzed.ResultsThere was a trend towards increasing IRLS severity category with increasing CGI-1, RLS-6, and RLS-QoL score. Pearson product moment correlation coefficients showed correlations between IRLS and comparator scale scores at baseline and EoM as well as correlations for change from baseline to EoM.ConclusionCorrelations between the IRLS and comparator scales were substantial. These data indicate that the IRLS is clinically meaningful. The IRLS and CGI-1 are generally sufficient to evaluate the overall severity and impact of RLS symptoms in clinical trials.     

Clinical efficacy of ropinirole for restless legs syndrome is not affected by age at symptom onset

ObjectiveTo determine whether clinical response to the dopamine agonist, ropinirole, in the treatment of primary restless legs syndrome (RLS), depends upon the age-at-onset of RLS symptoms.MethodsPooled data from four 12-week, randomized, double-blind, placebo-controlled studies of ropinirole in patients with moderate-to-severe primary RLS were analyzed post hoc. The relationship between age-at-onset and response to treatment, based on change from the baseline International Restless Legs Syndrome Study Group (IRLSSG) rating scale (the International Restless Legs Scale [IRLS]) total score and the proportion of responders (rated ‘much’/‘very much’ improved) on the Clinical Global Impression–Improvement (CGI-I) scale, was explored.ResultsThe range of age-at-onset of RLS symptoms was 2–75 years. No relationship was observed between the age-at-onset of RLS symptoms and baseline IRLS total score (correlation r = −0.06), and between dose administered at Week 12 last observation carried forward (LOCF) and age-at-onset (r = −0.04). The age-at-onset by treatment interaction was non-significant (P = 0.952 for the IRLS and P = 0.716 for the CGI-I scale), indicating there was no significant relationship between age-at-onset and the magnitude of ropinirole treatment effect.ConclusionsThese data suggest that ropinirole provides effective relief of symptoms, regardless of age at RLS symptom onset.     

Ropinirole is effective in the long-term management of restless legs syndrome: a randomized controlled trial.

The objective of this study was to investigate the long-term efficacy of ropinirole in patients with restless legs syndrome (RLS) and to assess the potential for relapse after the discontinuation of active treatment. Patients with primary RLS (n = 202) received single-blind ropinirole for 24 weeks. Patients meeting treatment continuation criteria were randomized to double-blind treatment with ropinirole or placebo for a further 12 weeks. The primary efficacy variable was the proportion of patients relapsing during double-blind treatment. Additional efficacy measures included time to relapse, withdrawals due to lack of efficacy, improvement on the Clinical Global Impression-Improvement (CGI-I) scale, change in International Restless Legs Scale (IRLS) score during double-blind treatment, and changes in sleep and quality of life (QoL) parameters. Significantly fewer patients relapsed on ropinirole than on placebo (32.6% vs. 57.8%; P = 0.0156). Time to relapse was longer with ropinirole and more patients withdrew due to lack of efficacy with placebo. Patients showed improvements in IRLS and CGI-I scores, sleep and QoL parameters with single-blind ropinirole, which were better maintained when ropinirole was continued during the double-blind phase, but reduced with placebo. Ropinirole was well tolerated; adverse events were typical for dopamine agonists. Ropinirole was highly effective and well tolerated in the long-term management of RLS, with pharmacological effect over 36 weeks.     

Patient characteristics predicting responses to intravenous ferric carboxymaltose treatment of restless legs syndrome

BackgroundSignificant benefit of intravenous ferric carboxymaltose (FCM) treatment for restless legs syndrome (RLS) has been well-established. However, no clinical indicators predicting treatment response of RLS have been established. This study aimed to determine factors predicting outcome of clinical FCM treatment of RLS patients.MethodsData were retrospectively reviewed from all patients who received FCM treatment for RLS from April 2016 to April 2019. These data included: detailed history, international RLS scale score (IRLS), questionnaires, comorbidity, and previous RLS medication use. Morning fasting serum iron, ferritin, and total iron-binding capacity were measured before and at four weeks after treatment. RLS patients with possible secondary RLS were identified by reviewing the medical histories. This included patients with iron deficiency anemia, lumbosacral radiculopathy, and gastrectomy. Primary RLS included those with no indication of secondary medical factors contributing to RLS. Treatment response was assessed using the IRLS and clinical ratings at four weeks after FCM administration. Patients with a greater than 40% decrease in IRLS were classified as responders.ResultsThe study comprised 164 patients with IRLS and clinical ratings obtained before and at four weeks after intravenous (IV) iron. Treatment responses differed considerably between diagnostic groups of RLS. Percentage responding was: 64.7% (66 of 102) for patients with primary RLS, 90.9% (10 of 11) with gastrectomy, 91.3% (21 of 23) with iron deficiency anemia and 39.3% (11 of 28) with lumbosacral radiculopathy. When responders were compared to non-responders in primary RLS patients, responders had significantly lower serum iron (80.5 ± 26.7 vs. 95.8 ± 30.5 μg/dL, p = 0.022) and percentage transferrin saturation (%TSAT) (25.4 ± 9.6 vs. 30.5 ± 10.5%, p = 0.026) in females, but not males. Logistic regression controlling for major subject variables showed that %TSAT significantly predicted response. (odds ratio [OR]: 0.955, confidence interval: 0.913–0.998, p = 0.040).ConclusionIntravenous FCM in moderate to severe RLS patients is beneficial as a first-line or add-on treatment, particularly for patients with compromised peripheral iron state. Overall, lower %TSAT predicted better chance of responding to the IV iron treatment especially for females.     

Clinical efficacy of ferric carboxymaltose treatment in patients with restless legs syndrome

ObjectiveThere have been three randomized, placebo-controlled, double-blind studies of intravenous iron in restless legs syndrome (RLS), with differing outcomes. The one positive study used ferric carboxymaltose (FCM) at a total dose of 1000 mg. The purpose of this study was to replicate and extend the findings from the prior FCM study.MethodsNon-anemic, idiopathic RLS patients were enrolled in a randomized, double-blinded, placebo-controlled study and received either 1000 mg FCM or placebo as a single infusion (phase I). Subjects were off any RLS medications for at least two weeks prior to baseline assessment. The primary outcome variable was change from baseline at week 6 on the International Restless Legs Syndrome Severity (IRLSS) scale and a subject-completed, visual analog scale (VAS) of severity. Phase II of the study involved long-term (30 weeks) follow-up after completion of the six-week efficacy phase.ResultsAt week 6 postinfusion, FCM compared to placebo recipients showed significantly greater change from baseline for both primary outcome measures (IRLSS scale, −11.9 ± 8.04 vs −7.88 ± 5.89, p = 0.03; VAS, −40.6 ± 22.7 vs −21.3 ± 20.0, p = 0.001). None of the secondary outcome variables showed a significant difference at week 6. After six weeks of treatment, the FCM group had 19 (59.4%) responders, of which 12 had IRLSS scores <10 (“remitters”). Twelve (37.5%) of the 32 subjects treated with iron in phase I remained free of further RLS medications at 30 weeks. There were no serious adverse events observed in this study.ConclusionTwo studies now support the value of FCM treatment both in the short term (six weeks) and long term (30 weeks) for improving RLS symptoms.     

Efficacy of vitamins C, E, and their combination for treatment of restless legs syndrome in hemodialysis patients: a randomized, double-blind, placebo-controlled trial

BackgroundRestless legs syndrome (RLS) is a common disorder in hemodialysis patients that leads to insomnia and impaired quality of life. Because high oxidative stress has been implicated in the pathogenesis of RLS, we sought to evaluate the efficacy of vitamins C and E and their combination in reducing the severity of RLS symptoms in hemodialysis patients in this randomized, double-blind, placebo-controlled, four-arm parallel trial.MethodsSixty stable hemodialysis patients who had all four diagnostic criteria for RLS developed by the International Restless Legs Syndrome Group with no acute illness or history of renal stone were randomly allocated to four fifteen-patient parallel groups to receive vitamin C (200 mg) and vitamin E (400 mg), vitamin C (200 mg) and placebo, vitamin E (400 mg) and placebo, and double placebo daily for eight weeks. International Restless Legs Scale (IRLS) scores were measured for all patients at baseline and at the end of treatment phase. The primary outcome was absolute change in IRLS sum score from baseline to the end of treatment phase.ResultsMeans of IRLS sum score decreased significantly in the vitamins C and E (10.3 ± 5.3, 95% CI: 7.4–13.3), vitamin C and placebo (10 ± 3.5, 95% CI: 8.1–11.9), and vitamin E and placebo groups (10.1 ± 6, 95% CI: 6.8–13.5) compared with the double placebo group (3.1 ± 3, 95% CI: 1.5–4.8), (P < 0.001); however, no differences were observed between these treatment groups.ConclusionsVitamins C and E and their combination are safe and effective treatments for reducing the severity of RLS in hemodialysis patients over the short-term.     

High false-positive rate of questionnaire-based restless legs syndrome diagnosis in multiple sclerosis

Background/ObjectivesRestless legs syndrome (RLS) is diagnosed by self-reported symptoms. Multiple sclerosis (MS) patients have disease-related symptoms which could mimic RLS. This study assessed the: (1) false-positive rate for questionnaire-based RLS diagnosis in MS patients and (2) utility of periodic leg movements during wakefulness (PLMW) on overnight polysomnography (PSG) in identifying true-positive RLS patients.MethodsAmbulatory MS patients without known sleep disorders were recruited. Subjects completed the International RLS Study Group (IRLSG) diagnostic questionnaire (IRLDQ) and underwent full overnight PSG. IRLDQ-positive patients underwent clinical evaluation to confirm the diagnosis and completed the RLS severity scale (IRLS).ResultsSeventy-one MS patients (mean age 46.8 ± 10.4 years) were evaluated. Thirty-eight had a positive IRLDQ. RLS diagnosis was confirmed in 22, yielding a false-positive rate of 42% [95% confidence interval (CI) 26–59%], predominantly attributable to paresthesiae (n = 7), and cramps and/or muscle spasms (n = 4). IRLS scores were not significantly different between subjects with confirmed and nonconfirmed RLS. The PLMW index was significantly higher in patients with confirmed RLS (55.4 ± 41.9 vs. 29.7 ± 18.8, p = 0.03). The sensitivity of a PLMW index >70/h for true-positive IRLDQ was 8/22 = 36%, 95% CI: 17.2–59.3, and the specificity was 16/16 = 100%, 95% CI: 79.4–100.ConclusionsMS patients have a high false-positive rate of RLS diagnosis using a standardized questionnaire largely attributable to MS-related sensorimotor symptoms. While detailed clinical evaluation is essential for confirming RLS diagnosis, the PLMW index may provide useful adjunctive information.     

Predictors of clinical response in a double-blind placebo controlled crossover trial of gabapentin enacarbil for restless legs syndrome

ObjectivesRestless Legs Syndrome (RLS) is a sensory-motor disorder which produces sleep disturbance. Using data from a large clinical trial of gabapentin enacarbil (GEn) we sought to assess the ability of baseline, and changes from baseline, in clinical trial endpoints to predict treatment response.MethodsData were derived from a randomized, double-blind, placebo-controlled, crossover polysomnography study of gabapentin enacarbil 1200 mg (n = 121) or placebo (n = 123). Efficacy evaluations included: sleep measures from polysomnography, subjective sleep measures, Suggested Immobilization Test (SIT) measures, and International Restless Legs Severity Scale (IRLS) and Clinical Global Impression-Improvement (CGI-I). Correlations were evaluated using Spearman's rank correlation coefficients. Predictors of treatment response were separately assessed for GEn and placebo using categorical IRLS and CGI-I outcomes. Stepwise logistic regression models ascertained which combination of baseline and change from baseline variables predicted response.ResultsModerate to large correlations were observed between changes in the IRLS and changes in subjective sleep for both GEn and placebo, substantially larger for GEn than placebo. Small to moderate correlations were present between the change in IRLS and the change in SIT-discomfort for both GEn and placebo. In the stepwise regression, for both GEn and placebo, baseline and change from baseline SIT discomfort, as well as change in sleep quality, were strong predictors of response.ConclusionsChanges in sleep quality, and baseline and changes in SIT discomfort were prominent predictors of treatment response for GEn and placebo. Predictors of treatment response may allow for more targeted enrollment in future clinical trials and may provide insights into the efficacy of RLS treatments.     

Restless legs syndrome in Egyptian medical students using a validated Arabic version of the Restless Legs Syndrome Rating Scale

ObjectiveRestless legs syndrome (RLS) is a common movement disorder that has a variable prevalence and impact reported from different countries and specific populations. The current study validated an Arabic version of the International Restless Legs Syndrome Study Group (IRLSSG) rating scale (IRLS) and investigated the prevalence and impact of RLS in medical students at Ain Shams University in Cairo.MethodsTranslation of IRLS was done according to standard recognized guidelines provided by the publisher. A total of 389 medical students (217 female and 172 male) participated in the study and answered four questions to detect RLS as proposed by the IRLSSG. Subjects who answered positively the first three questions were recruited for face-to-face interview to exclude RLS mimics and to answer the IRLS.ResultsA total of 46 subjects (11.8%; 27 female and 19 male) met the four criteria for RLS. Of these, 39 subjects (10%) had idiopathic RLS. Five subjects (1.3%) and two subjects (0.5%) reported association with history of anemia and diabetes mellitus respectively. Their mean total IRLS score was 16.33 ± 5.3, with moderate severity (11.62 ± 3.9) and low impact (3.1 ± 1.8). The prevalence of individuals who had two or more episodes of RLS of at least moderate severity per week was 5.9%.ConclusionIn this specific population of Egyptian medical students, a within-average prevalence of RLS was found with low impact on quality of life similar to worldwide reported populations. RLS sufferers were of high prevalence among this cohort. The Arabic version of IRLS is reliable and valid for further research in Arabic countries.