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

Periodic limb movement disorder in children: A systematic review

This systematic review evaluates the scientific literature on pediatric periodic limb movement disorder (PLMD), adhering to PRISMA guidelines and utilizing PICOS criteria. The search across PubMed, EMBASE, and Scopus yielded 331 articles, with 17 meeting inclusion criteria. Diagnostic criteria evolved, with polysomnography and PLMS index ≥5 required since 2003. Also, PLMD diagnosis mandates clinical consequences like insomnia, hypersomnia, and fatigue, excluding comorbidities causing sleep disruption. Prevalence in children is low (0.3%), emphasizing the need for meticulous investigation. Comorbidities, particularly the bidirectional relationship with ADHD, were explored. Challenges in diagnosis and understanding arise from overlapping conditions such as sleep disordered breathing, psychotropic medication, and criteria non-adherence. Despite generally good study quality, weaknesses include sample size justification and biases. The periodic leg movement index shows high sensitivity but low specificity, underscoring strict diagnostic criteria adherence. Diverse metrics for symptoms necessitate standardized approaches. Family history of RLS in children with PLMD suggests unexplored aspects. Treatment, mainly iron supplementation, lacks standardized assessment metrics. The review emphasizes diagnostic and treatment challenges, recommending unbiased studies with precise techniques. Comprehensive research, quantifying PLMS and objectively assessing sleep parameters, is crucial for advancing understanding in pediatric PLMD. PROSPERO REGISTRATION NUMBER: CRD42021251406.

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.

Common Childhood Sleep Problems and Disorders

BACKGROUND

Sleep insufficiency and disturbances affect the physical, cognitive, and emotional well-being of children.

OBJECTIVE

To perform a narrative review on common sleep problems and disorders encountered in primary care for children and adolescents.

METHODS

A search of English literature in the Pubmed and Google Scholar databases published from 1 January 2000 till 31 October 2021 was conducted with the keywords "sleep problem" or "sleep disorder" and "child" or "adolescent". Findings in the relevant articles and cross-references were compiled.

RESULTS

Sleep duration and habits of children vary widely across countries with different cultural backgrounds. There is robust evidence to support the promotion of positive bedtime routines and sleep hygiene as prevention and management of sleep problems. 15-70% of parents reported their children having sleep problems or disturbances. Common sleep complaints include difficulty in initiation or maintenance of sleep, abnormal behaviors or movements, snoring or abnormal breathing, and excessive daytime sleepiness. Comprehensive sleep history and a sleep diary are the first steps for evaluation. Home video and actigraphy may be used as preliminary tools to confirm the history. Referrals to a sleep specialist for polysomnography and other tests are needed, if suspecting specific sleep disorders, such as obstructive sleep apnea and narcolepsy, needs timely intervention. Common sleep disorders in different age groups encountered in primary care are reviewed with clinical features, indications for evaluation, and treatment options summarized.

CONCLUSION

Screening for sleep problems shall be an integral part of each child's health care visit. It is important to evaluate the impact of common sleep problems and identify specific sleep disorders for early intervention to prevent long-term adverse outcomes.

Sleep and Circadian Disturbances in Children With Neurodevelopmental Disorders

Sleep problems are highly prevalent in those with neurodevelopmental disorders (NDDs). We propose this is secondary to multiple factors that directly and indirectly negatively impact sleep and circadian processes in those with NDDs, which in turn, further perturbs development, resulting in a "developmental and sleep/circadian-related encephalopathy." In this review, we discuss select NDDs with known or suspected sleep and circadian phenotypes. We also highlight important considerations when evaluating and treating sleep and circadian disorders in these populations.

Polysomnographic study in pediatric neurofibromatosis type 1

Background

Neurofibromatosis type 1 (NF1) is a genetic disease that alters neurodevelopment. We aimed to analyze the sleep macrostructure of a sample of children affected by NF1 without neurocognitive co-morbidities and MRI reports of unidentified bright objects (UBOs).

Methods

A 100 pre-pubertal children participated in the cross-sectional study: 50 subjects were children diagnosed with NF1 and 50 subjects were typically developing healthy children (TDC). All participants underwent polysomnographic evaluation through which conventional sleep parameters were collected: Total sleep time (TST), Sleep latency (SOL), first REM latency (FRL), number of stage shifts/h (SS/h), number of awakenings/h (AWN/h), wake after sleep onset (WASO%), sleep efficiency percentage (SE%), percentage of sleep time spent in sleep stages 1 (N1%) and 2 (N2%), slow-wave sleep (N3%), and REM sleep (REM%). Additionally, nocturnal respiratory events such as apnea/hypopnea index (AHI), oxygen desaturation index (ODI), and periodic limb movement index (PLMI) were recorded.

Results

Neurofibromatosis type 1 children showed a reduction in sleep duration parameters (TST; p < 0.001), sleep efficiency (SE%; p < 0.001), and stage N2% (p < 0.001). Moreover, the number of awakenings per hour (AWN/h), wake after sleep onset (WASO%), and respiratory events such as AHI, ODI, and PLMI resulted higher in NF1 vs. TDC children.

Conclusion

The data showed that the sleep macrostructure differs between NF1 and TDC children. These findings suggest that the evaluation of sleep may provide useful support in corroborating the diagnosis and offers additional therapeutic management perspectives in NF1 and genetic neurodevelopmental disorders in general.

Pediatric sleep: current knowledge, gaps, and opportunities for the future

This White Paper addresses the current gaps in knowledge, as well as opportunities for future studies in pediatric sleep. The Sleep Research Society's Pipeline Development Committee assembled a panel of experts tasked to provide information to those interested in learning more about the field of pediatric sleep, including trainees. We cover the scope of pediatric sleep, including epidemiological studies and the development of sleep and circadian rhythms in early childhood and adolescence. Additionally, we discuss current knowledge of insufficient sleep and circadian disruption, addressing the neuropsychological impact (affective functioning) and cardiometabolic consequences. A significant portion of this White Paper explores pediatric sleep disorders (including circadian rhythm disorders, insomnia, restless leg and periodic limb movement disorder, narcolepsy, and sleep apnea), as well as sleep and neurodevelopment disorders (e.g. autism and attention deficit hyperactivity disorder). Finally, we end with a discussion on sleep and public health policy. Although we have made strides in our knowledge of pediatric sleep, it is imperative that we address the gaps to the best of our knowledge and the pitfalls of our methodologies. For example, more work needs to be done to assess pediatric sleep using objective methodologies (i.e. actigraphy and polysomnography), to explore sleep disparities, to improve accessibility to evidence-based treatments, and to identify potential risks and protective markers of disorders in children. Expanding trainee exposure to pediatric sleep and elucidating future directions for study will significantly improve the future of the field.

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 Role of Supplements and Over-the-Counter Products to Improve Sleep in Children: A Systematic Review

The sleep-wake cycle is a complex multifactorial process involving several neurotransmitters, including acetylcholine, norepinephrine, serotonin, histamine, dopamine, orexin and GABA, that can be, in turn, regulated by different nutrients involved in their metabolic pathways. Although good sleep quality in children has been proven to be a key factor for optimal cognitive, physical and psychological development, a significant and ever-increasing percentage of the pediatric population suffers from sleep disorders. In children, behavioral interventions along with supplements are recommended as the first line treatment. This systematic review was conducted, according to the PRISMA guidelines, with the purpose of assessing the principal nutrients involved in the pathways of sleep-regulating neurotransmitters in children and adolescents. Our focus was the utilization of over the counter (OTC) products, specifically iron, hydroxytryptophan, theanine and antihistamines in the management of different pediatric sleep disorders with the intention of providing a practical guide for the clinician.

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.

Sleep-Related Drug Therapy in Special Conditions: Children

Pharmacologic treatment of the most common pediatric sleep disorders lacks evidence, and alternative methods, which have been proved to alleviate the symptoms, are preferred in most cases. The implementation of specific guidelines is of great importance because sleep disorders in children are not rare and they can negatively affect children's development and their cognitive and social skills. This article summarizes the current therapeutic management of sleep disorders in children, bearing in mind the absence of evidence-based guidelines on this topic.

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.

Leg Movements during Sleep in Children Treated with Serotonergic Antidepressants

STUDY OBJECTIVES

To evaluate leg movements during sleep (LMS) in children taking serotonergic antidepressants, compared to those of children with restless legs syndrome (RLS) and controls, and to assess the time structure of intermovement intervals (IMI).

METHODS

Twenty-three children (12 girls, mean age 14.1 years) on antidepressants and with a total LMS index ≥15/hour, 21 drug-naïve RLS children (11 girls, mean age 13.6 years) also with total LMS index ≥15/hour, and 35 control children (17 girls, mean age 14.3 years) were recruited. LMS were scored and a series of parameters was calculated, along with the analysis of their time structure.

RESULTS

Children taking antidepressants showed higher total and periodic LMS (PLMS) indexes than both controls and RLS children, as well as higher short-interval and isolated LMS indexes than controls. LMS periodicity was highest in children on antidepressants. In children taking antidepressants, a well-defined PLMS IMI peak corresponding to ~10-60 s, with a maximum at ~20 s was present, which was much less evident in RLS patients and absent in controls. A progressive decrease of PLMS during the night and more frequent arousals were found in children on antidepressants and with RLS.

CONCLUSIONS

Children taking serotonergic antidepressants show higher periodicity LMS than children with RLS or controls and have a higher number of PLMS through the night. Antidepressant-associated PLMS in children seem to have features similar to PLMS of adults with RLS. Whether this is a marker of an increased risk to develop RLS later in life needs to be determined.

Sleep Disorders in Adults with Down Syndrome

Sleep disorders, despite being very frequent in adults with Down syndrome (DS), are often overlooked due to a lack of awareness by families and physicians and the absence of specific clinical sleep guidelines. Untreated sleep disorders have a negative impact on physical and mental health, behavior, and cognitive performance. Growing evidence suggests that sleep disruption may also accelerate the progression to symptomatic Alzheimer's disease (AD) in this population. It is therefore imperative to have a better understanding of the sleep disorders associated with DS in order to treat them, and in doing so, improve cognition and quality of life, and prevent related comorbidities. This paper reviews the current knowledge of the main sleep disorders in adults with DS, including evaluation and management. It highlights the existing gaps in knowledge and discusses future directions to achieve earlier diagnosis and better treatment of sleep disorders most frequently found in this population.

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.

Iron Deficiency and Its Role in Sleep Disruption in Patients With Angelman Syndrome

OBJECTIVE

To determine if Angelman syndrome patients with sleep complaints have an increased risk of iron deficiency, and if iron therapy improves their sleep difficulties.

BACKGROUND

About two-thirds of Angelman syndrome patients experience sleep difficulties, which are likely multifactorial. Because iron deficiency can contribute toward restlessness in sleep, we investigated whether it might be a contributing factor in this special population.

METHODS

This retrospective study involved medical record review of Angelman syndrome patients <18 years old who had attended our multidisciplinary Angelman syndrome clinic and had sleep complaints. Serum ferritin levels were compared to age- and sex-matched controls. Sleep history and nocturnal polysomnogram findings of the Angelman syndrome patients were also characterized.

RESULTS

Nineteen Angelman syndrome patients (9 female, mean age 6.2±4.4 years) were identified. All 19 reported sleep difficulties. The mean serum ferritin level was 19.9±8.5 μg/L, while that in controls was 27.8±17.8 μg/L (P value .13). The odds ratio of iron deficiency in Angelman syndrome compared to controls was 4.17 (95% confidence interval 1.23-14.10), using normal serum ferritin level of 24 μg/L based on literature. Fifteen Angelman syndrome patients underwent nocturnal polysomnogram with 9/15 showing an elevated periodic limb movement index (overall mean 9.8±10.4). Seventeen of 19 received iron therapy. Twelve had follow-up after iron therapy, with parents reporting improved sleep quality. Eight had serum ferritin levels rechecked after iron therapy, showing a mean increase of 24±5.1 μg/L.

CONCLUSIONS

Sleep difficulties in Angelman syndrome, though multifactorial, may in part be related to iron deficiency. Treatment with iron improved sleep to a modest degree in this population.

Nocturnal events in children: When and how to evaluate

Nocturnal events of wide variety and concern are frequently reported by patients and their caregivers. To evaluate suspected abnormal events, primary care physicians must first be familiar with normal behaviors, movements and breathing patterns. Abnormal nocturnal events can then be categorized as nocturnal seizure, parasomnia, sleep-related movement disorder or sleep-related breathing disorder. Diagnoses in the above categories can be made clinically; however, it is important to know when to refer for additional evaluation. Comprehensive literature review was undertaken of nocturnal and sleep-related disorders. This guide reviews nocturnal seizures, normal and abnormal nonepileptic movements and behaviors, discusses broad indications for referral for electroencephalography (EEG) or polysomnography (PSG), and guides counseling and management for patients and their families, ultimately aiding in interpretation of both findings and prognosis. Epilepsy syndromes can result in seizures during sleep or adjacent periods of wakefulness. Parasomnias and sleep-related movement disorders tend to also occur in childhood and may be distinguished clinically. Referral to additional specialists for specific studies including EEG or PSG can be necessary, while other times a knowledgeable and vigilant clinician can contribute to a prompt diagnosis based on clinical features. Nocturnal events often can be managed with parental reassurance and watchful waiting, but treatment or evaluation may be needed. Sleep-related breathing disorders are important to recognize as they present very differently in children than in adults and early intervention can be life-saving. This review should allow both primary and subspecialty non-neurologic pediatric and adolescent health care providers to better utilize EEG and PSG as part of a larger comprehensive clinical approach, distinguishing and managing both epileptic and nonepileptic nocturnal disorders of concern while fostering communication across providers to facilitate and coordinate better holistic long-term care of pediatric and adolescent patients.

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.

Sleep-Wake Disorders in Childhood

PURPOSE OF REVIEW

The presentation of sleep issues in childhood differs from the presentation in adulthood and may be more subtle. Sleep issues may affect children differently than adults, and distinct treatment approaches are often used in children.

RECENT FINDINGS

Sodium oxybate was approved by the US Food and Drug Administration (FDA) in October 2018 for an expanded indication of treatment of sleepiness or cataplexy in patients with narcolepsy type 1 or narcolepsy type 2 aged 7 years or older, with side effect and safety profiles similar to those seen in adults. Restless sleep disorder is a recently proposed entity in which restless sleep, daytime sleepiness, and often iron deficiency are observed, but children do not meet the criteria for restless legs syndrome or periodic limb movement disorder.

SUMMARY

Children's sleep is discussed in this article, including normal sleep patterns and effects of insufficient sleep. Sleep disorders of childhood are reviewed, including insomnia, obstructive sleep apnea, restless legs syndrome, parasomnias, narcolepsy, and Kleine-Levin syndrome. Children with neurologic issues or neurodevelopmental disorders frequently have sleep disorders arising from an interaction of heterogeneous factors. Further attention to sleep may often be warranted through a polysomnogram or referral to a pediatric sleep specialist. Sleep disorders may cause indelible effects on children's cognitive functioning, general health, and well-being, and awareness of sleep disorders is imperative for neurologists who treat children.

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.

High prevalence of periodic limb movements of sleep in children with Down syndrome

STUDY OBJECTIVES

Increased periodic limb movements of sleep (PLMS), > 5 events/h, are present in 1.2% to 7.7% of healthy children and associated with hypertension, attention deficit, and hyperactivity. This study sought to determine the prevalence of elevated PLMS in a large cohort of children with Down syndrome (DS) and their correlation with OSA and ferritin levels.

METHODS

Retrospective chart review of all children with DS ages 2 to 18 years in whom single baseline polysomnography (PSG) was performed at a pediatric hospital over 5 years.

RESULTS

A total of 418 children met inclusion criteria. Three hundred fifty-six children (85%) were referred because of concerns about sleep-disordered breathing; 49 (12%) were referred for screening per American Academy of Pediatrics (AAP) guidelines; and 13 (3%) because of concerns about restless legs or periodic limb movement disorder. One hundred thirty-nine children (33.3%) had elevated PLMS; they were younger (6.3 years) than those without elevated PLMS (7.7 years). OSA was present in 176/418 (42.1%) children, including 13/49 (26.2%) asymptomatic children referred for screening PSG. Ferritin levels were only recorded in the charts of 65 of the children with elevated PLMS (46.7%); in 36 (55.4%) levels were < 50 ng/mL.

CONCLUSIONS

PLMS were increased in a substantial number of this large cohort of children with DS. Additional studies are necessary to assess utility of laboratory testing to predicting PLMS in similar, at-risk, populations. Screening PSG has value in identifying OSA in young, ostensibly asymptomatic children with DS. The prevalence of OSA increased with age in this cohort, unlike in typical children, requiring health care providers to remain vigilant for its emergence across the lifespan.

Consensus guidelines on managing Rett syndrome across the lifespan

BACKGROUND

Rett syndrome (RTT) is a severe neurodevelopmental disorder with complex medical comorbidities extending beyond the nervous system requiring the attention of health professionals. There is no peer-reviewed, consensus-based therapeutic guidance to care in RTT. The objective was to provide consensus on guidance of best practice for addressing these concerns.

METHODS

Informed by the literature and using a modified Delphi approach, a consensus process was used to develop guidance for care in RTT by health professionals.

RESULTS

Typical RTT presents early in childhood in a clinically recognisable fashion. Multisystem comorbidities evolve throughout the lifespan requiring coordination of care between primary care and often multiple subspecialty providers. To assist health professionals and families in seeking best practice, a checklist and detailed references for guidance were developed by consensus.

CONCLUSIONS

The overall multisystem issues of RTT require primary care providers and other health professionals to manage complex medical comorbidities within the context of the whole individual and family. Given the median life expectancy well into the sixth decade, guidance is provided to health professionals to achieve current best possible outcomes for these special-needs individuals.

Neurocognitive and behavioral significance of periodic limb movements during sleep in adolescents with attention-deficit/hyperactivity disorder

Study Objectives

The purpose of this study is to examine the association of abnormal periodic limb movements during sleep (PLMS) with neurocognitive and behavioral outcomes in adolescents with attention-deficit/hyperactivity disorder (ADHD) from the general population.

Methods

Four hundred twenty-one adolescents (17.0 ± 2.3 years, 53.9% male) from the Penn State Child Cohort, a random general population sample, underwent 9 hr polysomnography, clinical history, physical examination, neurocognitive evaluation, and completed the Child or Adult Behavioral Checklist (C/ABCL). The presence of ADHD was ascertained by parent- or self-report of receiving a diagnosis of ADHD. PLMS were defined as a PLM index (PLMI) of ≥5 events per hour of sleep.

Results

Adolescents with ADHD (n = 98) had a significantly higher PLMI (5.4 ± 7.3) and prevalence of PLMS (35%) when compared with controls (3.4 ± 5.6, p = 0.006 and 21%, p = 0.004). Significant interactions between ADHD and PLMS showed that adolescents with both disorders (n = 35) were characterized by deficits in control interference, as measured by Stroop test, and elevated internalizing behaviors, as measured by C/ABCL. ADHD severity and externalizing behaviors were elevated in a dose-response manner across ADHD-alone (n = 63) and ADHD + PLMS groups. The association of ADHD with other neurocognitive functions did not vary as a function of PLMS.

Conclusions

PLMS are significantly more frequent in adolescents with ADHD. Importantly, adolescents with both disorders not only have worse neurobehavioral functioning than adolescents with ADHD-alone but specifically presented with executive deficits and anxiety symptoms. These data suggest that PLMS may be a marker of more severe underlying neurobiological deficits in adolescents with ADHD and comorbid internalizing problems.

Improvement of Parasomnias After Treatment of Restless Leg Syndrome/ Periodic Limb Movement Disorder in Children

STUDY OBJECTIVES

Previous studies have shown that non-rapid eye movement (NREM) sleep parasomnias commonly coexist with restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) in children, leading to speculation that RLS/PLMD may precipitate or worsen parasomnias. However, there are limited data about the effect of the treatment of RLS/PLMD on parasomnias in children. Hence, we performed this study to determine whether the treatment of RLS/PLMD with oral iron therapy is associated with improvement of parasomnias in children.

METHODS

A retrospective database was created for children with RLS/PLMD who were treated with iron therapy. These participants were followed for at least 1 year at Cincinnati Children's Hospital Medical Center. All participants had ferritin level testing and were treated with iron therapy. In addition, all participants underwent polysomnography before starting iron therapy for RLS/PLMD except for one participant who was already on iron but required a higher dose. Most participants underwent polysomnography after iron therapy.

RESULTS

A total of 226 participants were identified with the diagnosis of RLS/PLMD. Of these, 50 had parasomnias and 30 of them were treated with iron therapy. Of the 30 participants, RLS symptoms improved in 15 participants (50%) and resolution of parasomnias was noted in 12 participants (40%) participants after iron therapy. Repeat polysomnography after iron therapy was performed in 21 participants (70%). After iron therapy, there was a significant decrease in periodic limb movement index (17.2 ± 8.8 [before] versus 6.7 ± 7.3 [after] events/h, P < .001). In addition, there were significant decreases in PLMS (24.52 ± 9.42 [before] versus 7.50 ± 7.18 [after] events/h, P < .0001), PLMS-related arousals (4.71 ± 1.81 [before] versus 1.35 ± 1.43 [after] events/h, P < .0001), and total arousals (11.65 ± 5.49 [before] versus 8.94 ± 3.65 [after] events/h, P < .01) after iron therapy.

CONCLUSIONS

Parasomnias are common in our cohort of children with RLS/PLMD. Iron therapy was associated with a significant improvement in periodic limb movement index, RLS symptoms, and resolution of a significant proportion of NREM sleep parasomnias, suggesting that RLS/PLMD may precipitate NREM sleep parasomnia.

How I approach iron deficiency with and without anemia

Iron deficiency anemia remains a common referral to the pediatric hematology-oncology subspecialist. Improved understanding of iron homeostasis, including the effects of the regulatory hormone hepcidin, recent adult and pediatric clinical trial data, as well as the availability of safer formulations of intravenous iron, have resulted in additional considerations when making treatment recommendations in such patients. Young children and adolescent females remain the most commonly affected groups, but children with complex medical or chronic inflammatory conditions including comorbid gastrointestinal disorders also require special consideration.

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.].

Sleep-Related Drug Therapy in Special Conditions: Children

Sleep disorders in children may lead to neurodevelopmental and neurocognitive deficits; it is important to diagnose and treat them properly. Apart from the existing challenges in diagnosis, another drawback is that few therapies are currently approved. In this article, a comprehensive summary of the most common pediatric sleep disorders, along with the various pharmacologic and nonpharmacologic approaches for their management, is presented. Special attention has been paid to the currently available treatment options for pediatric insomnia, obstructive sleep apnea, parasomnias, narcolepsy, and restless legs syndrome, and comparisons are made with the corresponding treatment options for sleep disorders in adults.

Sleep disorders during childhood: a practical review

Sleep disorders are a common problem during childhood. The consequences are variable, and sleep disorders can influence medical, psychological and developmental aspects of the growing child. It is important to recognize sleep disorders and to treat them correctly. We discuss common sleep disorders during childhood using the 3rd edition of the International Classification of Sleep Disorders. We analyze the different sleep disorders from a clinical approach and provide an overview of adequate treatment options.Conlusion: This review discusses common sleep disorders during childhood using the 3rd edition of the International Classification of Sleep Disorders. We analyze the different sleep disorders from a clinical approach and provide an overview of adequate treatment options. What is known: • Sleep disorders are a common problem during childhood. • The consequences are variable, and sleep disorders can influence medical, psychological, and developmental aspects of the growing child. What is new: • Pediatricians should routinely screen for sleep and sleep disorders. • It is important to recognize sleep disorders and to treat them correctly.

Iron Sulfur and Molybdenum Cofactor Enzymes Regulate the Drosophila Life Cycle by Controlling Cell Metabolism

Iron sulfur (Fe-S) clusters and the molybdenum cofactor (Moco) are present at enzyme sites, where the active metal facilitates electron transfer. Such enzyme systems are soluble in the mitochondrial matrix, cytosol and nucleus, or embedded in the inner mitochondrial membrane, but virtually absent from the cell secretory pathway. They are of ancient evolutionary origin supporting respiration, DNA replication, transcription, translation, the biosynthesis of steroids, heme, catabolism of purines, hydroxylation of xenobiotics, and cellular sulfur metabolism. Here, Fe-S cluster and Moco biosynthesis in Drosophila melanogaster is reviewed and the multiple biochemical and physiological functions of known Fe-S and Moco enzymes are described. We show that RNA interference of Mocs3 disrupts Moco biosynthesis and the circadian clock. Fe-S-dependent mitochondrial respiration is discussed in the context of germ line and somatic development, stem cell differentiation and aging. The subcellular compartmentalization of the Fe-S and Moco assembly machinery components and their connections to iron sensing mechanisms and intermediary metabolism are emphasized. A biochemically active Fe-S core complex of heterologously expressed fly Nfs1, Isd11, IscU, and human frataxin is presented. Based on the recent demonstration that copper displaces the Fe-S cluster of yeast and human ferredoxin, an explanation for why high dietary copper leads to cytoplasmic iron deficiency in flies is proposed. Another proposal that exosomes contribute to the transport of xanthine dehydrogenase from peripheral tissues to the eye pigment cells is put forward, where the Vps16a subunit of the HOPS complex may have a specialized role in concentrating this enzyme within pigment granules. Finally, we formulate a hypothesis that (i) mitochondrial superoxide mobilizes iron from the Fe-S clusters in aconitase and succinate dehydrogenase; (ii) increased iron transiently displaces manganese on superoxide dismutase, which may function as a mitochondrial iron sensor since it is inactivated by iron; (iii) with the Krebs cycle thus disrupted, citrate is exported to the cytosol for fatty acid synthesis, while succinyl-CoA and the iron are used for heme biosynthesis; (iv) as iron is used for heme biosynthesis its concentration in the matrix drops allowing for manganese to reactivate superoxide dismutase and Fe-S cluster biosynthesis to reestablish the Krebs cycle.

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.