Treatment of pediatric restless legs syndrome

Restless Legs Syndrome in Children and Adolescents

Children with psychiatric comorbidities frequently are referred for evaluation of sleep complaints. Common sleep symptoms can include difficulty falling asleep, frequent nocturnal awakening, restless sleep, and symptoms of restless legs syndrome (RLS). The understanding of the sleep condition in relation to the psychiatric comorbidity often is a challenge to the physician and often sleep disorders remain undiagnosed, untreated, or undertreated. Restless legs syndrome has been associated with psychiatric comorbidities and with certain medications, such as antidepressants, antihistamines, and antipsychotics. This article reviews the presentation of RLS and restless sleep, the association with psychiatric comorbidities, and treatment options.

Restless Legs Syndrome and Restless Sleep Disorder in Children

Restless legs syndrome (RLS) affects 2% of children presenting with symptoms of insomnia, restless sleep, decreased quality of life, and effects on cognition and behavior. The International RLS Study Group and the American Academy of Sleep Medicine have published guidelines for the diagnosis and treatment of RLS in children. Restless sleep disorder has been recently identified in children and presents with frequent movements during sleep and daytime symptoms with polysomnography findings of at least 5 large muscle movements at night. Treatment options for both disorders include iron supplementation, either oral or intravenous with improvement in nighttime and daytime symptoms.

The prevalence of the restless legs Syndrome/Willis-Ekbom disease among teenagers, its clinical characteristics and impact on everyday functioning

BACKGROUND AND AIMS

The data on the prevalence of the Restless Legs Syndrome/Willis -Ekbom disease (RLS/WED) in the population of teenagers is scarce. The aim of this study was to determine RLS/WED occurrence in adolescents, its diagnostic accuracy, family history, clinical characteristics and impact on everyday functioning.

MATERIAL AND METHODS

A group of 2379 pupils (aged 13-18 y.o.) from 6 randomly selected secondary schools in Gdańsk, Poland were screened for RLS/WED with the use of a questionnaire. In order to verify the diagnosis and perform additional tests (neurological examination, psychological evaluation, biochemical blood tests, demographic questionnaire, International RLS rating scale/IRLSS, Epworth daytime sleepiness scale). all of the respondents with RLS/WED suspicion and their parents were asked for a consultation by a child neurologist. Both children and parents with RLS/WED diagnosis were tested with actigraphy at home for at least two consecutive nights.

RESULTS

Two thousand and ninety seven students (88,15%) filled the questionnaire correctly (1171 girls and 926 boys, 56% and 44%). Sixty four respondents were suspected of having RLS/WED (3,1%), however, 36 of them were diagnosed as RLS/WED-mimics (mainly positional discomfort). Finally, 21 (1%) were diagnosed with definite idiopathic RLS/WED. The average age of symptom onset was 10.96 years. The severity was moderate in the most of the cases (61.9%) and the course of the disease was intermittent in all of them. Family history was positive in 80%. Abnormal actigraphy (PLMS index >5/h) was present in 80%. Blood level of ferritin was low (<50 ng/ml) in 85%. Excessive daytime sleepiness and school problems affected almost half of them. The presence of RLS/WED symptoms was associated with disrupted sleep, behavioral problems (irritability, aggression, hyperactivity), attention deficit and lowered mood. No correlation between RLS/WED and attention deficit hyperactivity disorder (ADHD), nocturnal enuresis or primary headaches was found. Thirty eight percent of the patients sought medical help, but none of them obtained proper diagnosis nor treatment of RLS/WED.

CONCLUSIONS

In this study restless legs syndrome affected 1% of Polish teenagers, in the majority of cases was idiopathic and associated with positive family history. It affected sleep and everyday functioning. Neurological consultation is essential to avoid false positive diagnoses of RLS/WED in teenagers.

Clinical efficacy and safety of intravenous ferric carboxymaltose treatment of pediatric restless legs syndrome and periodic limb movement disorder

BACKGROUND

Iron supplementation is the most commonly considered treatment option for children with restless legs syndrome (RLS) or periodic limb movement disorder (PLMD); however, there is a scarcity of evidence on the effectiveness of intravenous preparations. In this study, we evaluated the effectiveness and tolerability of intravenous ferric carboxymaltose (IV FCM) on clinical symptoms and iron indices in children with RLS or PLMD.

METHODS

This was a single-center retrospective data analysis. Children with a diagnosis of RLS or PLMD, who underwent a single infusion of IV FCM, were included. Clinical Global Impression (CGI) Scale scores, serum ferritin, and serum iron profile at baseline and after eight weeks post infusion were obtained. Adverse effects were assessed.

RESULTS

Thirty-nine children received IV FCM, 29 with RLS and 10 with PLMD. Pre-infusion CGI-Severity revealed moderate illness, with post-infusion CGI-Improvement between "very much improved" and "much improved". Ferritin increased from 14.6 μg/L±7.01 to 112.4 μg/L±65.86 (p < 0.00001), together with improvements in iron, total iron binding capacity, and transferrin levels from baseline to post-treatment. When compared to children with RLS, those with PLMD had a similar improvement in clinical symptoms and laboratory parameters. Seven subjects (14.3%) experienced one or two adverse events; all were mild.

CONCLUSIONS

Children with RLS and PLMD responded to IV iron supplementation with improvement in both clinical severity and laboratory parameters. Treatment was well tolerated. Although larger, randomized-controlled trials are needed, IV FCM appears to be a promising alternative to oral iron supplementation for the treatment of pediatric RLS or PLMD.

Comparison between oral ferrous sulfate and intravenous ferric carboxymaltose in children with restless sleep disorder

STUDY OBJECTIVES

Recent work has identified clinical and polysomnographic features of a newly defined pediatric sleep disorder, restless sleep disorder (RSD). One of these features is low serum ferritin. In this retrospective, pilot study, we assess the response to iron supplementation. Children were given oral ferrous sulfate (FS) or intravenous ferric carboxymaltose (IV FCM).

METHODS

Children 5-18 years old with a diagnosis of RSD were evaluated clinically. Serum ferritin, iron profile, and video-polysomnography were obtained at baseline. Oral or IV iron supplementation was offered as part of routine care. Oral FS was one 325 mg tablet daily or 3 mg/kg/day liquid for 3 months. IV FCM was 15 mg/kg, up to 750 mg as a single infusion. Adverse effects were assessed. Ferritin and iron profile were checked after 2-3 months. Eight weeks after FCM, the phosphorus level was checked. Clinical Global Impression (CGI) scale was obtained pre- and posttreatment.

RESULTS

A total of 15 children received oral FS and 15 IV FCM. Baseline RSD severity, age, gender, or pretreatment lab values did not differ significantly between groups. CGI-improvement median score was "minimally improved" after oral FS and "much improved" after IV FCM (effect size 1.008, p < 0.023). All iron parameters were found to be significantly higher after intravenous iron treatment than oral iron, especially ferritin (effect size 3.743, p < 0.00003). Adverse effects: constipation, three with FS; noncompliance, one with FS; syncope, one with FCM infusion; and hypophosphatemia, zero post-FCM.

CONCLUSIONS

In this retrospective, clinical case series, RSD responded to iron supplementation with improvement in both clinical and laboratory parameters. The response was greater with IV FCM than oral FS.

Pediatric Restless Legs Syndrome

Early-onset restless legs syndrome has a relatively high prevalence in pediatrics, is highly familial, and is often preceded by a diagnosis of periodic limb movement disorder or childhood insomnia. Diagnostic criteria are derived but not equal to those of the adult syndrome and are adapted according to children's age and linguistic competence. Diagnosis requires parents or caregivers to participate; video-polysomnographic nocturnal recording, although not mandatory, may help confirm dubious cases. The syndrome severely impacts children's sleep and cognitive-behavioral abilities. Iron supplementation is currently the most used and viable therapeutic option.

Restless Legs Syndrome in Children and Adolescents

Children with psychiatric comorbidities frequently are referred for evaluation of sleep complaints. Common sleep symptoms can include difficulty falling asleep, frequent nocturnal awakening, restless sleep, and symptoms of restless legs syndrome (RLS). The understanding of the sleep condition in relation to the psychiatric comorbidity often is a challenge to the physician and often sleep disorders remain undiagnosed, untreated, or undertreated. Restless legs syndrome has been associated with psychiatric comorbidities and with certain medications, such as antidepressants, antihistamines, and antipsychotics. This article reviews the presentation of RLS and restless sleep, the association with psychiatric comorbidities, and treatment options.

Does Improvement of Low Serum Ferritin Improve Symptoms of Restless Legs Syndrome in a Cohort of Pediatric Patients?

STUDY OBJECTIVES

To determine whether an oral iron supplement improves restless leg/restless sleep symptoms in a pediatric population.

METHODS

In a cohort study, 47 patients (age 5-18 years) exhibiting restless legs/restless sleep symptoms and low serum ferritin levels (< 50 ng/mL) were given a daily oral iron supplement (ferrous sulfate + vitamin C) and re-evaluated 8 weeks later. A diagnosis of definite Restless Legs Syndrome (RLS) was determined based on criteria established by the International RLS Study Group. Using Wilcoxon signed-rank tests and Spearman rho, the change and association between the measures of Pediatric Restless Legs Syndrome Severity Scale and serum ferritin levels were also examined.

RESULTS

Overall, the median change and distribution of ferritin was statistically significantly different after 8 weeks of treatment (40.0 versus 23.0 ng/mL, P < .0001). Median RLS score was also statistically significantly lower from baseline to follow-up (4.0 versus 6.0, P = .0283). Sixteen patients met criteria for definite RLS; however, the change in RLS score was not determined to be significant in our population (9.5 versus 7.0, P = .0558), despite significant change in ferritin (25.0 versus 42.5 ng/mL, P < .0001). In addition, no correlation was observed between change in RLS score and ferritin level (rho = -.39, P = .1362).

CONCLUSIONS

In preliminary findings, we found a modest, yet nonsignificant improvement in children exhibiting restless sleep and RLS symptomatology, despite significant improvement in ferritin levels. Though not statistically significant, the findings can lend to the suggested benefit of iron supplementation in patients with RLS; however, clinical judgment and further research is necessary.

CITATION

Rosen GM, Morrissette S, Larson A, Stading P, Barnes TL. Does improvement of low serum ferritin improve symptoms of restless legs syndrome in a cohort of pediatric patients? J Clin Sleep Med. 2019;15(8):1149-1154.

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.

Randomized, Placebo-Controlled Trial of Ferrous Sulfate to Treat Insomnia in Children With Autism Spectrum Disorders

BACKGROUND

Insomnia and low iron stores are common in children with autism spectrum disorders, and low iron stores have been associated with sleep disturbance.

METHODS

We performed a randomized placebo-controlled trial of oral ferrous sulfate to treat insomnia in children with autism spectrum disorders and low normal ferritin levels. Twenty participants who met inclusion criteria and whose insomnia did not respond to sleep education were randomized to 3 mg/kg/day of ferrous sulfate (n = 9) or placebo (n = 11) for three months.

RESULTS

Iron supplementation was well tolerated, and no serious adverse events were reported. Iron supplementation improved iron status (+18.4 ng/mL active versus -1.6 ng/mL placebo, P = 0.044) but did not significantly improve the primary outcome measures of sleep onset latency (-11.0 minutes versus placebo, 95% confidence interval -28.4 to 6.4 minutes, P = 0.22) and wake time after sleep onset (-7.7 minutes versus placebo, 95% confidence interval -22.1 to 6.6 min, P = 0.29) as measured by actigraphy. Iron supplementation was associated with improvement in the overall severity score from the Sleep Clinical Global Impression Scale (-1.5 points versus placebo, P = 0.047). Changes in measures of daytime behavior did not differ between groups.

CONCLUSION

This trial demonstrated no improvement in primary outcome measures of insomnia in subjects treated with ferrous sulfate compared with placebo. Interpretation was limited by low enrollment.

Limb movements during sleep in children: effects of age, sex, and iron status in more than 1,000 patients referred to a pediatric sleep center

STUDY OBJECTIVES

Limb movements during sleep (LMS) and periodic limb movements during sleep (PLMS) have been shown to vary by age in children. In the current study, we examined this relationship in more detail in a large clinically referred sample adjusting for iron status and sex.

METHODS

Retrospective data analysis was done on a large pediatric population who underwent an overnight sleep study and had ferritin levels measured within 30 days of sleep study between May 2013 and October 2017 at pediatric sleep center. Patients with obstructive or central sleep apneas were excluded.

RESULTS

A total of 1,070 patients were included in the study, with 60% males. Younger age and male sex were associated with increased PLMS and LMS. In addition, there was an increase in PLMS and LMS during adolescence that subsided at a later age, independent of sex. These associations remained significant in models controlling for ferritin level. Ferritin level, in contrast, was not a significant predictor of PLMS or LMS when controlling for sex and age.

CONCLUSIONS

Age and sex may need to be considered when interpreting limb movement indices in pediatric sleep patients regardless of ferritin level.

Restless Legs Syndrome in Children

Restless legs syndrome (RLS) is a common pediatric condition that often goes undiagnosed. The genetics and pathophysiology of this sensorimotor condition are still not well understood. RLS can affect any part of the body, but the thighs and calves are the most commonly affected. Because of unpleasant sensations caused by RLS, these patients experience sleep disturbance and its consequences. The diagnosis of RLS is a clinical one. RLS occurs at a higher frequency and the symptoms are more severe in patients with iron deficiency; therefore, correcting iron deficiency improves the symptoms. Both pharmacologic and nonpharmacologic interventions can be effective in the treatment of children with RLS. However, in contrast to adults with RLS, most children with RLS are not treated with pharmacologic agents because the symptoms are not as severe as they are in adults. [Pediatr Ann. 2018;47(12):e504-e506.].

Pharmacological Management of Restless Legs Syndrome and Periodic Limb Movement Disorder in Children

Restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) are under-recognized sleep disorders in children and adolescents. Several recent epidemiological studies have shown that RLS and PLMD are common in the pediatric population, and if left untreated, may lead to cardiovascular and neurocognitive consequences. Therefore, early diagnosis and intervention may help preventing long-term consequences. The management of RLS and PLMD in children involves both non-pharmacologic and pharmacologic approaches. Although there is emerging literature supporting medical therapy in children with RLS and PLMD, the overall experiences with these medications remain limited. Most children and adolescents with RLS and PLMD have low iron storage; therefore, iron therapy should be considered as the first line of treatment in children. Currently, there is no FDA-approved medication for RLS and PLMD in children. There is increasing evidence on the effectiveness of dopaminergic medications in children but the data are quite limited. Other medications such as α2δ-1 ligands, benzodiazepine, and clonidine are frequently used, but have not been adequately investigated in children. Further studies are needed to evaluate the safety and efficacy of pharmacologic therapy for RLS and PLMD in children.

Evidence-based and consensus clinical practice guidelines for the iron treatment of restless legs syndrome/Willis-Ekbom disease in adults and children: an IRLSSG task force report

BACKGROUND

Brain iron deficiency has been implicated in the pathophysiology of RLS, and current RLS treatment guidelines recommend iron treatment when peripheral iron levels are low. In order to assess the evidence on the oral and intravenous (IV) iron treatment of RLS and periodic limb movement disorder (PLMD) in adults and children, the International Restless Legs Syndrome Study Group (IRLSSG) formed a task force to review these studies and provide evidence-based and consensus guidelines for the iron treatment of RLS in adults, and RLS and PLMD in children.

METHODS

A literature search was performed to identify papers appearing in MEDLINE from its inception to July 2016. The following inclusion criteria were used: human research on the treatment of RLS or periodic limb movements (PLM) with iron, sample size of at least five, and published in English. Two task force members independently evaluated each paper and classified the quality of evidence provided.

RESULTS

A total of 299 papers were identified, of these 31 papers met the inclusion criteria. Four studies in adults were given a Class I rating (one for IV iron sucrose, and three for IV ferric carboxymaltose); only Class IV studies have evaluated iron treatment in children. Ferric carboxymaltose (1000 mg) is effective for treating moderate to severe RLS in those with serum ferritin <300 μg/l and could be used as first-line treatment for RLS in adults. Oral iron (65 mg elemental iron) is possibly effective for treating RLS in those with serum ferritin ≤75 μg/l. There is insufficient evidence to make conclusions on the efficacy of oral iron or IV iron in children.

CONCLUSIONS

Consensus recommendations based on clinical practice are presented, including when to use oral iron or IV iron, and recommendations on repeated iron treatments. New iron treatment algorithms, based on evidence and consensus opinion have been developed.

Identification and treatment of augmentation in patients with restless legs syndrome: practical recommendations

Restless legs syndrome (RLS) is a chronic disorder causing clinically significant discomfort to approximately 3% of adults. Although RLS was first identified centuries ago, our understanding of this disorder, its causes, and its treatments is still evolving. In particular, our knowledge of the potential negative effects of RLS treatments, including dopaminergic augmentation, continues to expand. Augmentation, which refers to a paradoxical treatment-related increase in RLS symptoms, has been associated with all three dopamine agonists approved for the treatment of RLS - rotigotine, pramipexole, and ropinirole. This review presents key information on prevention and treatment of dopaminergic augmentation from the recently published consensus-based guidelines issued by the International RLS Study Group task force in conjunction with the European RLS Study Group and the RLS Foundation for first-line treatment of RLS/Willis-Ekbom disease. If dopamine agonists are used to treat RLS, it is recommended that the dosage should be kept as low as possible without exceeding the maximum dose recommended for RLS treatment. As the frequency of augmentation with the rotigotine patch may only be slightly lower than that associated with pramipexole or ropinirole, medications that are effective and have little risk of augmentation, such as alpha-2-delta ligands, may be considered for initial RLS treatment. In addition, we present our clinical experience with treating patients with dopaminergic augmentation by highlighting 2 case studies and practical considerations when treating different patient populations. Applying current RLS augmentation diagnosis and treatment guidelines, as well as collecting detailed histories of worsening RLS symptoms, is critical for patient safety and effective management of RLS augmentation.

Sleep patterns in male juvenile monkeys are influenced by gestational iron deprivation and monoamine oxidase A genotype

Individual differences in sleep patterns of children may have developmental origins. In the present study, two factors known to influence behavioural development, monoamine oxidase A (MAOA) genotype and prenatal Fe-deficient (ID) diet, were examined for their influences on sleep patterns in juvenile rhesus monkeys. Sleep patterns were assessed based on a threshold for inactivity as recorded by activity monitors. Pregnant monkeys were fed diets containing either 100 parts per million (ppm) Fe (Fe sufficient, IS) or 10 ppm Fe (ID). At 3-4 months of age, male offspring were genotyped for polymorphisms of the MAOA gene that lead to high or low transcription. At 1 and 2 years of age, sleep patterns were assessed. Several parameters of sleep architecture changed with age. At 1 year of age, monkeys with the low-MAOA genotype demonstrated a trend towards more sleep episodes at night compared with those with the high-MAOA genotype. When monkeys reached 2 years of age, prenatal ID reversed this trend; ID in the low-MAOA group resulted in sleep fragmentation, more awakenings at night and more sleep episodes during the day when compared with prenatal IS in this genotype. The ability to consolidate sleep during the dark cycle was disrupted by prenatal ID, specifically in monkeys with the low-MAOA genotype.