Pharmacological responsiveness of periodic limb movements in patients with restless legs syndrome: a systematic review and meta-analysis.

STUDY OBJECTIVES: Periodic limb movements during sleep (PLMS) are a frequent finding in restless legs syndrome, but their impact on sleep is still debated, as well the indication for treatment. We systematically reviewed the available literature to describe which drug categories are effective in suppressing PLMS, assessing their efficacy through a meta-analysis, when this was possible. METHODS: The review protocol was preregistered on PROSPERO (CRD42021175848), and the systematic search was conducted on and EMBASE (last searched on March 2020). We included original human studies, which assessed PLMS modification on drug treatment with a full-night polysomnography, through surface electrodes on each tibialis anterior muscle. When at least 4 studies were available on the same drug or drug category, we performed a random-effect model meta-analysis. RESULTS: Dopamine agonists like pramipexole and ropinirole resulted the most effective, followed by l-dopa and other dopamine agonists. Alpha2delta ligands are moderately effective as well opioids, despite available data on these drugs are much more limited than those on dopaminergic agents. Valproate and carbamazepine did not show a significant effect on PLMS. Clonazepam showed contradictory results. Perampanel and dypiridamole showed promising but still insufficient data. The same applies to iron supplementation. CONCLUSIONS: Dopaminergic agents are the most powerful suppressors of PLMS. However, most therapeutic trials in restless legs syndrome do not report objective polysomnographic findings, there is a lack of uniformity in presenting results on PLMS. Longitudinal polysomnographic interventional studies, using well-defined and unanimous scoring criteria and endpoints on PLMS are needed. CITATION: Riccardi S, Ferri R, Garbazza C, Miano S, Manconi M. Pharmacological responsiveness of periodic limb movements in patients with restless legs syndrome: a systematic review and meta-analysis. J Clin Sleep Med. 2023;19(4):811-822.

Intravenous iron therapy in the pediatric sleep clinic: a single institution experience.

STUDY OBJECTIVES: Initial reports of intravenous (IV) iron administration have been promising for children with restless legs syndrome, periodic limb movement disorder, and restless sleep disorder. The aim of the current study was to evaluate further the clinical response to IV iron supplementation in children seen in a pediatric sleep clinic. METHODS: We performed a retrospective chart review of children cared for in a single pediatric sleep clinic who also underwent IV iron infusion. Pre and post IV data regarding their sleep symptoms and ferritin levels were abstracted. RESULTS: Overall, 63 pediatric sleep patients underwent IV iron infusion, mostly with ferric carboxymaltose (n = 60), for restless legs syndrome (n = 30), periodic limb movement disorder (n = 22), and restless sleep disorder (n = 17). Of the 59 patients with clinical follow-up, 39 (73%) noted improvement in at least 1 symptom, and 14 (26%) did not notice improvement or noticed worsening symptoms. Of the 59 patients with preinfusion and postinfusion labs, the average ferritin level increased from 21.7 (13.3) to 147.9 (120.9) µg/L, P < .001. Comparing patients who experienced clinical improvement vs those who did not, there were no statistically significant differences in change in ferritin levels (P = .278), sex (P = .452), or age (P = .391). Ferritin change with infusion according to diagnostic subgroups (restless legs syndrome/periodic limb movement disorder/restless sleep disorder) was examined, and no significant differences were noted (F(2,56) = 0.852, P = .432). In terms of immediate adverse reactions to the IV infusion, 7 (11%) experienced at least 1 side effect, with the most common being behavior change (n = 6) or gastrointestinal discomfort (n = 4); no episodes of anaphylaxis or extravasation were noted. CONCLUSIONS: These data provide additional support for the efficacy and safety of IV iron for pediatric restless legs syndrome, periodic limb movement disorder, and restless sleep disorder recalcitrant to oral iron. CITATION: Ingram DG, Al-Shawwa B, DelRosso LM, Sharma M. Intravenous iron therapy in the pediatric sleep clinic: a single institution experience. J Clin Sleep Med. 2022;18(11):2545-2551.

Determinants of ferritin response to oral iron supplementation in children with sleep movement disorders.

STUDY OBJECTIVES: To identify children who respond to oral iron supplementation as evidenced by increased ferritin levels and to identify factors that correlate with improvement in ferritin levels in those who respond. METHODS: A retrospective chart review of the PLMS/RLS/RSD database at Seattle Children's Hospital was carried out. Data collected included nocturnal polysomnography parameters, age, sex, initial and follow-up ferritin level and date of collection, and presence of restless legs syndrome (RLS), periodic limb movements of sleep (PLMS)/PLM disorder (PLMD), restless sleep disorder (RSD), obstructive sleep apnea (OSA), neurologic, psychiatric, neurodevelopmental, or medical comorbidity. Oral iron therapy was evaluated by side effects (none; constipation; bad taste/nausea), subjective outcome in symptoms (resolved, improved, no change), and adherence to therapy (poor, fair, good). RESULTS: Seventy-seven children were included in this study of whom 42 were classified as responders (increase in ferritin of ≥10 µg/L) and 35 were nonresponders. Age and sex were not different between groups. Adherence was the only significant predictor of an increase in ferritin of ≥10 µg/L. Constipation was seen in 7.1% of responders vs. 45.8% of nonresponders. No change in symptoms was reported in 26.2% of responders vs. 71.4% in nonresponders. A significant correlation was found between treatment duration and ferritin level change in responders but not in nonresponders. CONCLUSIONS: Side effects hinders adherence to oral iron supplementation in children. Responders to oral iron show improvement in ferritin levels and symptoms, while nonresponders show no improvement in ferritin levels despite a long-lasting treatment, at least in part of them.

Magnesium supplementation for the treatment of restless legs syndrome and periodic limb movement disorder: A systematic review.

Magnesium supplementation is often suggested for restless legs syndrome (RLS) or period limb movement disorder (PLMD) based on anecdotal evidence that it relieves symptoms and because it is also commonly recommended for leg cramps. We aimed to review all articles reporting the effects of magnesium supplementation on changes in RLS and/or PLMD. We conducted a systematic search looking for all relevant articles and then two reviewers read all article titles and abstracts to identify relevant studies. Eligible studies were scored for their quality as interventional trials. We found 855 abstracts and 16 of these could not be definitively excluded for not addressing all aspects of our research question. Seven full-text articles were unlocatable and one was ineligible which left eight studies with relevant data. One was a randomised placebo-controlled trial, three were case series and four were case studies. The RCT did not find a significant treatment effect of magnesium but may have been underpowered. After quality appraisal and synthesis of the evidence we were unable to make a conclusion as to the effectiveness of magnesium for RLS/PLMD. It is not clear whether magnesium helps relieve RLS or PLMD or in which patient groups any benefit might be seen.

Outcomes of long-term iron supplementation in pediatric restless legs syndrome/periodic limb movement disorder (RLS/PLMD).

OBJECTIVES: Restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are thought to center around a genetically mediated sensitivity to iron insufficiency. Previous studies have shown the effectiveness of short-term iron therapy in children with low iron storage. Little is known, however, about long-term iron treatment in children with RLS and PLMD. Therefore, we performed this study to assess the long-term effect of iron therapy in children with RLS and PLMD. METHODS: A retrospective chart review was performed for children who met the following criteria: A) diagnosed as having either RLS or PLMD, B) started on iron supplementation, C) followed up for >2 years in a sleep clinic. Baseline values for iron, ferritin, and periodic limb movement of sleep index (PLMS index) were defined in the three months leading up to the initiation of iron therapy. Values were also computed for follow-up periods of 3-6 months, 1-2 years, and >2 years. Serum iron and ferritin levels and PLMS index were compared between baseline and all subsequent follow-ups. RESULTS: In total, 105 patients met inclusion criteria, of whom 64 were diagnosed with PLMD alone, seven with RLS alone, and 35 with both RLS and PLMD. The average age was 10.2 ± 5.3 years. Compared to the baseline (27.4 ± 12.1 ng/ml), the average ferritin values at 3-6 months (45.62 ± 21.2 ng/ml, p < 0.001, n = 34), 1-2 years (52.0 ± 48.3 ng/ml, p <0.001, n = 63), and >2 years (54.7 ± 40.5 ng/ml, p <0.001, n = 67) were all significantly increased. Inversely, compared to baseline (21 ± 27.0/h, n = 66), PLMS index values at 3-6 months (7.5 ± 9.5/h p < 0.05, n = 11), 1-2 years (6.9 ± 8.9/h, p <0.001, n = 29), and >2 years (10 ± 14.5/h, p <0.001, n = 31) were all significantly decreased. No significant change in serum iron levels was noted at any time point. CONCLUSION: While retrospective in nature, this study demonstrates a sustained improvement in PLMS index and maintenance of adequate ferritin levels >2 years after iron therapy initiation in our RLS/PLMD cohort with a long-term follow-up. Iron therapy appears to lead to long-lasting improvements in children with RLS/PLMD.

Treatment of childhood-onset restless legs syndrome and periodic limb movement disorder using intravenous iron sucrose.

OBJECTIVE: An alternative treatment approach is needed for children who cannot tolerate oral iron preparations or when there is a need for rapid replenishment of iron stores. We report on the safety, adverse effects, and efficacy of intravenous iron sucrose in a retrospective sample of children with restless legs syndrome (RLS) or periodic limb movement disorder (PLMD). METHODS: Sixteen children with RLS/PLMD who received intravenous iron sucrose at our institution between 2005 and 2011 were identified. The diagnosis of RLS/PLMD was established after formal sleep consultation and nocturnal polysomnography (PSG). Serum ferritin was assayed in all 16 subjects prior to iron sucrose infusion and in 14 subjects after infusion. The medical records were reviewed for treatment-related details. RESULTS: The mean age of subjects was 6.6 years (range, 2-16 y; 5/16 girls). The mean periodic limb movement index (PLMI) was 18.2±12.8. Fifteen of the 16 subjects (93.7%) had systemic or neurologic comorbidities. Fourteen of 16 (87.5%) subjects had received prior oral iron supplementation for sleep-related concerns, with the majority of the subjects either having gastrointestinal (GI) side effects or insufficient benefits. Intravenous iron sucrose therefore was provided to these 16 subjects through our outpatient pediatric infusion therapy center. The average dose of intravenous iron sucrose of 3.6 mg/kg was infused over 2 h. The baseline mean serum ferritin was 16.4±6.6 ng/mL. After infusion with intravenous iron sucrose, the mean serum ferritin rose to 45.7±22.4 ng/mL (n=14; [95% confidence interval, 17.2-41.3]; P<.0001). Parental assessment of response to iron sucrose therapy was conducted on follow-up clinic visits or via telephone calls. There was improved sleep in 62.5% (n=10) of subjects and no improvement in 12.5% (n=2) of subjects. No follow-up information was available for 25% (n=4) of subjects. Minor adverse events occurred in 25% (n=4) of subjects--two subjects experienced difficulty with peripheral intravenous catheter placement, while two had transient GI symptoms, such as anorexia, nausea, and vomiting. None of the subjects had anaphylaxis. CONCLUSIONS: Intravenous iron sucrose appears to be a relatively effective therapy for patients with childhood-onset RLS/PLMD and iron deficiency who do not tolerate or respond to oral iron supplements. Side effects were transient. The most common adverse events were difficulty with intravenous line placement and GI disturbance. There is a need for systematic prospective studies on the safety and efficacy of intravenous iron sucrose in RLS/PLMD in children.

Restless legs syndrome and periodic limb movements during sleep: diagnosis and treatment.

BACKGROUND: Restless legs syndrome (RLS) and periodic limb movements during sleep (PLMS) have been known for over 300 years, and they may be present in as many as 25% of patients who have sleep disorders. These patients generally present with insomnia. These disorders often remain undiagnosed for an average of 16 years and patients have seen an average of 13 physicians for their symptoms. Therefore, these disorders merit the attention and interest of the practitioner, so that such patients can be evaluated and treated without delay. REVIEW SUMMARY: The important features of these disorders are the following: (1) their recognition since 1685, (2) they may comprise up to 25% of all sleep disorders, (3) they require differentiation from many other disorders, and (4) effective treatment is available. Although it is believed that RLS and PLMS are 2 clinical manifestations of the same central nervous system dysfunction, they are generally discussed separately, as different nosological entities. CONCLUSION: RLS and PLMS are common neurologic disorders and increase in prevalence with aging. These disorders can be disabling conditions, causing sleep disturbance at night and excessive sleepiness during the day. Polysomnography and the suggested immobilization test are used to support the clinical diagnosis of RLS and PLMS. Although levodopa alleviates symptoms, rebound and augmentation occur frequently, limiting the long-term usefulness of this agent. The direct dopamine receptor agonists such as pergolide, pramipexole, ropinirole, and cabergoline have largely replaced levodopa as the most effective treatment for RLS and PLMS.

[Restless legs syndrome and periodic limb movements during sleep in a patient with obstructive sleep apnea]. / Zespól niespokojnych nóg i okresowe ruchy konczyn w czasie snu u chorego na obturacyjny bezdech senny.

A case of moderate obstructive sleep apnea in which effective treatment with continuous positive airway pressure did not reduce excessive daytime sleepiness was described. Polysomnography with tibial muscles activity recording revealed frequent periodic limb movements in sleep (PLMS) with sleep fragmentation. PLMS index was 13.6/h of sleep. Clonazepam combined with iron and magnesium supplementation reduced limb movements, excessive daytime sleepiness and improved the patient's mood. Causes of PLMS and treatment options are discussed. PLMS and restless legs syndrome (RLS) should be considered in the differential diagnosis of excessive daytime sleepiness.

Effects of deep brain stimulation of the subthalamic nucleus on sleep architecture in parkinsonian patients.

Patients affected by Parkinson's disease (PD) often complain of disturbed sleep resulting from nighttime motor disabilities such as nocturnal akinesia, tremor and rigidity, motor behaviour during REM sleep or periodic leg movements (PLM) during sleep. Sleep may also be affected by dopaminergic and anticholinergic drugs or coexisting depressive syndrome. Deep brain stimulation (DBS) of subthalamic nucleus (STN) effectively reduces PD motor disability. The aim of this study is to evaluate the sleep architecture modifications after STN DBS. We assessed five patients (two men and three women, mean age 63.8+/-3.3 years, with a mean history of PD of 13.8+/-4.9 years) who underwent STN DBS. The mean levodopa equivalent dosage (LED) was 1010+/-318 mg before surgery and 116+/-93 mg 3 months after surgery. Polysomnography (PSG) with audiovisual recordings was performed on two separate nights, the first assessment in the week before surgery and the second 3 months after surgery. Three months after surgery, PSG showed an increase in total sleep time, in the longest period of uninterrupted sleep, and in the percentage of stage 3-4 NREM sleep, while there was a reduction of wakefulness after sleep onset. PLM, apnea-hyopnea index and REM sleep behaviour disorder were unaffected by STN DBS. STN DBS seems to be an effective therapeutic option for the treatment of advanced Parkinson's disease because it improves the cardinal symptoms and also seems to improve sleep architecture.

Practice parameters for the treatment of restless legs syndrome and periodic limb movement disorder. An American Academy of Sleep Medicine Report. Standards of Practice Committee of the American Academy of Sleep Medicine.

These are the first clinical guidelines published for the treatment of Restless Legs Syndrome (RLS) and Periodic Limb Movement Disorder (PLMD) providing evidence-based practice parameters. They were developed by the Standards of Practice Committee and reviewed and approved by the Board of Directors of the American Academy of Sleep Medicine. The guidelines provide recommendations for the practice of sleep medicine in North America regarding the treatment of RLS and PLMD. Recommendations are based on the accompanying comprehensive review of the medical literature regarding treatment of RLS and PLMD which was developed by a task force commissioned by the American Academy of Sleep Medicine. Recommendations are identified as standards, guidelines, or options, based on the strength of evidence from published studies that meet criteria for inclusion. Dopaminergic agents are the best studied and most successful agents for treatment of RLS and PLMD. Specific recommendations are also given for the use of opioid, benzodiazepine, anticonvulsant, and adrenergic medications, and for iron supplementation. In general, pharmacological treatment should be limited to individuals who meet diagnostic criteria and especially who experience insomnia and/or excessive sleepiness that is thought to occur secondary to RLS or PLMD. Individuals treated with medication should be followed by a physician and monitored for clinical response and adverse effects. It would be desirable for future investigations to employ multicenter clinical trials, with expanded numbers of subjects using double-blind, placebo-controlled designs, and an assessment of long-term response, side effects, and impact of treatment on quality of life. Evaluation of special groups such as children, pregnant women, and the elderly is warranted.