Consensus diagnostic criteria for a newly defined pediatric sleep disorder: restless sleep disorder (RSD)

Manual scoring of periodic limb movements in children: is it still necessary?

OBJECTIVE

Although manual scoring has been classically considered the gold standard to identify periodic leg movements (PLM), it is a very time consuming and expensive process, also subject to variability in interpretation. In the last decades, different authors have observed reasonably good agreement between automated PSG scoring algorithms and manual scoring in adults, according to established criteria. We aim to compare the automatic software analysis of our polysomnogram with the manual staging in children with sleep-disordered breathing.

METHODS

We performed a semiautomatic method, in which an experienced technician watched the video recording and removed from the automatic analysis those movements that did not correspond to true candidate leg movement (LM).

RESULTS

A total of 131 PSGs were studied; applying the established criteria, 65 children were diagnosed of obstructive sleep apnea, and 66 presented snoring but with no sleep apnea. The mean age was 6.7 years (±1.7) and twenty-five children (19.08 %) had a PLMI >5/h. Statistical differences were found not only for PLMI (manual: 2.20 (0.7, 4.1) vs automatic (6.4 (3.85,9.5); p < 0.001), but for almost of all indexes assessed between the automatic and the manual scoring analysis. The level of concordance was only moderate for PLM index (0.63 [0.51-0.72]); showing that, unlike the articles published in the adult population, automatic analysis is not accurate in children and, manually or semi-automatically analysis as ours need to be done.

CONCLUSION

It seems that PLM detection algorithm might work accurately but, the real need would be a true LM detection algorithm.

Clinical and video-polysomnographic characterization of restless sleep disorder in adult patients

Adults with restless sleep disorder (RSD) have never been studied clinically and polysomnographically. This study aimed to describe the clinical manifestation, duration, and distribution of sleep-related movements in adult patients with restless sleep disorder. Patients who had performed VPSG from Jan 2021 to Jan 2022 and met the diagnosis criteria of RSD were enrolled in the study. Patients' bed partners were also interviewed or telephoned in identifying this disorder. Scoring of movements during sleep was according to the diagnosis criteria of RSD and scoring of large muscle group movements during sleep proposed by the International RLS Study Group in 2020 and 2021, respectively. The clinical manifestation, the distribution of sleep stage as well as the types and duration of the movements were carefully recorded and analyzed. We included ten patients in the study with a mean age of 27.6 years (range 22-38). There was a male prevalence in adults with RSD. The study highlighted the findings from video-polysomnography, which indicated frequent sleep-related movements occurring throughout the Night. These movements were most prominent during N1 and N2 sleep stage, followed by REM sleep, while fewer movements were observed during N3 sleep. Adults with RSD experienced significant daytime functioning impairments, including non-refreshing sleep, daytime fatigue/sleepiness, and mood disturbance. Two of the patients in the study were diagnosed with anxiety and depression, further underscoring the impact of RSD on mental health. Adult patients also suffer from severe RSD, and the RSD that originates in childhood tends to persist into adulthood. In these cases, longer duration of the disease and poor sleep quality may be associated with an increased risk of developing psychiatric comorbidities. Our cases represent an objectively documented type of RSD in younger adult patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s41105-024-00524-1.

Sleep problems and circadian rhythm functioning in autistic children, autism with co-occurring attention deficit hyperactivity disorder, and typically developing children: A comparative study

LAY ABSTRACT

Sleep problems are common in autism spectrum disorder (ASD) and different factors can contribute to its occurrence in this population. Misalignment of the biological clock (our circadian system) has been described as one possible explanation. While there is a body of research on sleep problems, relatively less is known about circadian functioning and the specific population of autistic children with co-occurring attention deficit hyperactivity disorder (ADHD). Using an ambulatory circadian monitoring (ACM) system, which resembles a common watch, we gathered sleep parameters and the different rhythms obtained from measuring motor activity, light exposure and distal temperature in 87 autistic children and adolescents, 27 of whom were diagnosed with co-occurring ADHD, and 30 neurotypical children and adolescents as a comparison group. Autistic children and, especially, those with co-occurring ADHD showed greater motor activity during sleep which would be worth studying in future projects which could better define this restless sleep. Of note, we observed an atypical pattern of wrist temperature, with higher values in neurotypical children, followed by autistic children and, ultimately, those with co-occurring ADHD. Temperature is one of the most valuable factors evaluated here as it is closely connected to sleep-wakefulness and the hormone melatonin. Its special pattern during day and nighttime would support the hypothesis of an atypical secretion of melatonin in autistic individuals which would also link with the higher presence of sleep problems in this neurodevelopmental condition.

Polysomnographically Defined Restless Sleep Disorder and Periodic Limb Movements during Sleep in Children Born Prematurely

INTRODUCTION

Children born prematurely (<37 weeks' gestation) are at increased risk of perinatal complications, comorbidities, and iron deficiency. Iron deficiency is associated with restless legs syndrome and periodic limb movement disorder. In this study, we assessed the prevalence of restless sleep disorder (RSD) and elevated periodic limb movements during sleep (PLMS) in children born prematurely who underwent polysomnography.

METHODS

A retrospective chart review of sleep studies was conducted in children aged 1-18 years (median age 4 years) with a history of premature birth. Children with genetic syndrome, airway surgery, or tracheostomy were excluded. Three groups were compared: children with PLMS index >5, children with RSD, and children with neither elevated PLMS index nor RSD.

RESULTS

During the study, 2577 sleep studies were reviewed. Ninety-two studies fit our criteria and were included in the analysis. The median age at birth was 31 weeks, and the interquartile range (IQR) was 27-34 weeks. A total of 32 (34.8%) children were referred for restless sleep and 55 (59.8%) for snoring. After polysomnography, 18% were found to have a PLMS index >5/h, and 14% fit the criteria for restless sleep disorder (RSD). There were no statistically significant differences in PSG parameters among the children with RSD, PLMS, and the remaining group, except for lower obstructive apnea/hypopnea index (Kruskal-Wallis ANOVA 8.621, p = 0.0135) in the RSD group (median 0.7, IQR 0.3-0.9) than in the PLMS (median 1.7, IQR 0.7-3.5) or the non-RSD/non-PLMS (median 2.0, IQR 0.8-4.5) groups.

CONCLUSIONS

There was an elevated frequency of RSD and elevated PLMS in our cohort of children born prematurely. Children born prematurely are at higher risk of iron deficiency which can be a contributor factor to sleep -related movement disorders. These results add new knowledge regarding the prevalence of RSD and PLMS in these children.

Sleep Problems, Circadian Rhythms, and Their Relation to Behavioral Difficulties in Children and Adolescents with Autism Spectrum Disorder

This was an exploratory cross-sectional study comparing 45 children with ASD to 24 typically developing drug-naïve controls, group-matched on age, sex, and body mass index. Objective data was obtained using the following: an ambulatory circadian monitoring device; saliva samples to determine dim light melatonin onset (DLMO): and three parent-completed measures: the Child Behavior Checklist (CBCL); the Repetitive Behavior Scale-Revised (RBS-R); and the General Health Questionnaire (GHQ28). The CBCL and RBS-R scales showed the highest scores amongst poor sleepers with ASD. Sleep fragmentation was associated with somatic complaints and self-injury, leading to a higher impact on family life. Sleep onset difficulties were associated with withdrawal, anxiety, and depression. Those with phase advanced DLMO had lower scores for "somatic complaints"; "anxious/depressed" state; and "social problems", suggesting that this phenomenon has a protective role.

Sleep and Autism: Current Research, Clinical Assessment, and Treatment Strategies

Autism spectrum disorder is associated with a high rate of sleep problems, affecting over 80% of autistic individuals. Sleep problems have pervasive negative effects on health, behavior, mood, and cognition but are underrecognized in autistic children. Problems initiating and maintaining sleep-hallmarks of insomnia-are common. Sleep-disordered breathing and restless legs syndrome have also been described in autism at a higher prevalence than in community populations. The authors describe current research on sleep in autistic children and potential pathophysiologic mechanisms. They describe practical approaches to sleep assessment and synthesize approaches to addressing sleep problems in autistic children.

Restless sleep disorder in a sample of children and adolescents with autism spectrum disorder: preliminary results from a case series

STUDY OBJECTIVES

Sleep disorders are a frequent comorbidity among children with autism spectrum disorder (ASD). Among sleep-related issues of ASD, restless sleep is a common complaint. In recent years, restless sleep disorder (RSD) has been proposed as a new clinical entity, characterized by agitated sleep as its predominant manifestation. Despite the high prevalence of sleep disorders and data reporting restless sleep among ASD patients, to date no study has yet characterized RSD within patients with ASD. Therefore, the aim of our study was to assess the occurrence of RSD in a sample of children and adolescents with ASD through clinical and polysomnographic assessment.

METHODS

Children and adolescents with ASD ages 6-18 years were recruited for the study. Through parental interviews, patients with a suspected RSD were selected and offered diagnostic investigation by video-polysomnography and blood tests to assess martial balance.

RESULTS

Among the 129 participants included, 16 patients (12.4%) were found to have a suspected RSD. Only 6 (4.7%) underwent video-polysomnography due to lack of compliance or family refusal. In 6/6 participants examined, the disorder was confirmed by video-polysomnography movement analysis (total movement index ≥ 5 events/h) and ferritin values were found in the normal range.

CONCLUSIONS

RSD does not appear to be particularly frequent among patients with ASD and that of iron metabolism may not be the main factor implicated in the pathogenesis of RSD within this population. Additional evaluation is needed to confirm the result and further investigate the etiological mechanisms underlying the disorder.

CITATION

Voci A, Mazzone L, De Stefano D, Valeriani M, Bruni O, Moavero R. Restless sleep disorder in a sample of children and adolescents with autism spectrum disorder: preliminary results from a case series. J Clin Sleep Med. 2024;20(3):427-432.

The association of obstructive sleep apnea and behavioral insomnia in children ages 10 and under

STUDY OBJECTIVES

Behavioral insomnia of childhood (BIC) and obstructive sleep apnea (OSA) are highly prevalent conditions affecting 10%-20% and 1%-5% of children, respectively. Studies in adults and adolescents have suggested that comorbid insomnia and OSA may have distinct clinical characteristics. The association between the two conditions in the pediatric population has not been thoroughly investigated. This study aimed to examine the association between BIC and OSA in young children.

METHODS

Children, 6 months to 10 years old, referred to a sleep specialist and polysomnography at the Hadassah Medical Center between 2018 and 2021 were included in this retrospective analysis. We excluded children with chromosomal and craniofacial abnormalities, posttonsillectomy, or neurological impairment. BIC diagnosis was extracted from the electronic health records in accordance with the International Classification of Sleep Disorders, third edition criteria. OSA was diagnosed by polysomnography (apnea-hypopnea index > 2 events/h).

RESULTS

Of 312 children (age 4.42 ± 2.42 years), 126 (40.4%) were non-OSA non-BIC, 125 (40.1%) OSA non-BIC, 34 (10.9%) BIC non-OSA, and 27 (8.7%) comorbid insomnia and OSA. OSA and non-OSA children had a similar prevalence of BIC. Children in the comorbid insomnia and OSA group were significantly younger (2.22 ± 1.21 years). Younger age at polysomnography, premature birth, and increased periodic leg movements on polysomnography were independently associated with OSA in a multivariable analysis. Lower body mass index, regardless of OSA, was associated with BIC.

CONCLUSIONS

Current findings do not support an association between behavioral insomnia of childhood and obstructive sleep apnea in children. Healthcare providers should consider each of these sleep disorders in children presenting with sleep difficulties since each has distinct diagnostic and therapeutic options.

CITATION

Yelov L, Reiter J, Meira E Cruz M, Gileles-Hillel A. The association of obstructive sleep apnea and behavioral insomnia in children ages 10 and under. J Clin Sleep Med. 2024;20(2):245-251.

Restless sleep disorder in children with epileptic and non-epileptic nocturnal attacks

Restless sleep disorder (RSD) is an important sleep disorder characterised by the presence of frequent large muscle movements (LMM) during sleep, which may be comorbid to other conditions/diseases. In this study, we investigated the frequency and the characteristics of RSD among children who were evaluated by polysomnography (PSG) due to epileptic and non-epileptic nocturnal attacks. We analysed consecutively children younger than 18 years who were referred for PSG recording due to abnormal motor activities during sleep. The diagnosis of nocturnal events as sleep-related epilepsy was made based on the current consensus. Patients who were referred with suspicion of sleep-related epilepsy, but who were diagnosed to have non-epileptic nocturnal events and children with a definitive diagnosis of NREM sleep parasomnias were also enrolled. Sixty-two children were analysed in this study (17 children with sleep-related epilepsy, 20 children with NREM parasomnia, and 25 children with nocturnal events not otherwise classified [neNOS]). The mean number of LMM, LMM index, LMM-associated with arousal and its index were all significantly higher in children with sleep-related epilepsy. Restless sleep disorder was present in 47.1% of patients with epilepsy, 25% of patients with parasomnia, and in 20% of patients with neNOS. The mean A3 duration and the A3 index were higher in children with sleep-related epilepsy and RSD compared with those with parasomnia and restless sleep disorder. Patients with RSD had lower ferritin levels than those without RSD in all subgroups. Our study demonstrates a high prevalence of restless sleep disorder in children with sleep-related epilepsy, associated with an increased cyclic alternating pattern.

Large muscle group movements during sleep in healthy people: normative values and correlation to sleep features

STUDY OBJECTIVES

To investigate the frequency and characteristics of large muscle group movements (LMMs) during sleep in healthy adults.

METHODS

LMMs were scored following the International Restless Legs Syndrome Study Group criteria in 100 healthy participants aged 19-77 years. A LMM was defined as a temporally overlapping increase in EMG activity and/or the occurrence of movement artifacts in at least two channels. LMM indices and durations in total sleep time (TST), NREM and REM sleep, and association with arousals, awakenings, and/or respiratory events were calculated. Correlations of LMMs indices and durations with sleep architecture, respiratory and motor events, and subjective sleep quality were investigated.

RESULTS

Median LMMs index in TST was 6.8/h (interquartile range (IQR), 4.5-10.8/h), median mean duration 12.4 s (IQR 10.7-14.4 s). Mean LMMs duration was longer in NREM (median 12.7 s, IQR 11.1-15.2 s) versus REM sleep (median 10.3 s, IQR 8.0-13.5s), p < 0.001. LMMs associated with awakening increased with age (p = 0.029). LMMs indices in TST were higher in men than women (p = 0.018). LMMs indices correlated positively with N1 sleep percentage (ρ = 0.49, p < 0.001), arousal index (ρ = 0.40, p = 0.002), sleep stages shift index (ρ = 0.43, p < 0.001, apnea index (ρ = 0.36, p = 0.017), and video-visible movements indices (ρ = 0.45, p < 0.001), and negatively with N3 sleep (ρ = -0.38, p= 0.004) percentage.

CONCLUSIONS

This is the first study providing normative data on LMMs frequency in healthy adults. LMMs are a ubiquitous phenomenon often associated with other events. Correlation with arousals and respiratory events suggests a potential clinical significance of LMMs in adults that awaits further investigation.

Sleep Disorders in Childhood

OBJECTIVE

This article provides a comprehensive review of pediatric sleep disorders including the clinical features, diagnosis, and treatment of sleep-disordered breathing, insomnia, parasomnias, restless sleep disorder, restless legs syndrome, narcolepsy in childhood, and Kleine-Levin syndrome.

LATEST DEVELOPMENTS

Our understanding of pediatric sleep pathophysiology continues to evolve, and diagnostic and treatment modalities have expanded. A low-sodium oxybate formulation was approved in July 2020 in the United States to treat cataplexy and excessive daytime sleepiness in patients 7 years old and older with narcolepsy. A validated pediatric hypersomnolence survey for pediatric narcolepsy and idiopathic hypersomnia with high sensitivity, specificity, and interrater reliability is now available.

ESSENTIAL POINTS

The clinical presentation, diagnostics, and treatment of children with sleep disorders differ from those of adults. Untreated sleep disorders in childhood can lead to adverse physical and psychological consequences in adults. Correctly diagnosing and treating sleep disorders in youth can prevent a significant burden of disease in adulthood.

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.

Sleep habits and sleep disorders in Italian children and adolescents: a cross-sectional survey

STUDY OBJECTIVES

The aim was to describe sleep habits and epidemiology of the most common sleep disorders in Italian children and adolescents.

METHODS

This was a cross-sectional study in which parents of typically developing children and adolescents (1-18 years) completed an online survey available in Italy, gathering retrospective information focusing on sleep habits and disorders.

RESULTS

Respondents were 4,321 typically developing individuals (48.6% females). Most of our sample did not meet the age-specific National Sleep Foundation recommendations for total sleep duration (31.9% of toddlers, 71.5% of preschoolers, 61.6% of school-age children, and 41.3% of adolescents). Napping was described in 92.6% of toddlers and in 35.2% of preschoolers. Regarding geographical differences, children and adolescents of northern Italy showed more frequent earlier bedtimes and rise times than their peers of central and southern Italy. The most frequently reported sleep disorder in our sample was restless sleep (35.6%), followed by difficulties falling asleep (16.8%), > 2 night awakenings (9.9%), and bruxism (9.6%). Data also suggest that longer screen time is associated with later bedtimes on weekdays in all age groups.

CONCLUSIONS

The current study shows that Italian children are at risk of sleep disorders, particularly insufficient sleep, restless sleep, and difficulty falling asleep. The study also provides normative sleep data by age group in a large cohort of typically developing Italian children, emphasizing the importance of the developmentally, ecologically, and culturally based evaluation of sleep habits and disorders.

CITATION

Breda M, Belli A, Esposito D, et al. Sleep habits and sleep disorders in Italian children and adolescents: a cross-sectional survey. J Clin Sleep Med. 2023;19(4):659-672.

Moving toward standardization: physician reporting of sleep studies

Detailed primary data collected from sleep studies should lead to specific and clear reports with evidence-based clinical recommendations that, when introduced by sleep medicine specialists, create a window of opportunity to support our non-sleep medicine referring teams and to engage patients and caregivers in their care as recipients of the reports. This is how sleep study reporting differs from other test reports; currently, there is wide variation in how the data collected are presented and summarized. The goal of this document is to offer recommendations for structured reporting of sleep studies. We offer a practical, complete, and relevant document and a structure that can be implemented across sleep centers nationwide and does not burden the interpreter. We anticipate some readers will opine that some of the content is beyond the scope of what the interpreter physician needs to include, while others will propose missing data that they feel should have been included. We feel that the flexibility of the proposal accommodates for this and allows for a "first step" toward standardization of physician reporting of sleep studies. High-quality structured reporting of sleep studies is becoming ever more important for patient care, benefiting patients, caregivers, clinicians, durable medical equipment companies, and payers.

CITATION

Lastra AC, Ingram D, Park J, et al. Moving toward standardization: physician reporting of sleep studies. J Clin Sleep Med. 2023;19(3):595-603.

Actigraphy evaluation before and after intravenous ferric carboxymaltose in 3 children with restless sleep disorder

Restless sleep disorder has been described in the literature as a disorder affecting children and presenting with large muscle movements during sleep with an index of 5 events/h or more, leading to daytime impairment including sleepiness or behavioral problems. Children with restless sleep disorder have been found to have low ferritin levels. Studies with iron supplementation both oral or intravenous have been shown effective in clinically improving both nighttime and daytime symptoms. However objective data of the improvement is lacking. Repeating polysomnography is expensive, and alternative methods of assessing large muscle movements are needed. In this small case series we present actigraphy results in 3 children with restless sleep disorder collected for 1 week, a week before and 8 weeks after intravenous iron supplementation. Although actigraphy parameters were not highly consistent between our 3 patients, improvement in symptoms tend to parallel sleep parameters in actigraphy.

CITATION

Chu ZYB, DelRosso LM, Mogavero MP, Ferri R. Actigraphy evaluation before and after intravenous ferric carboxymaltose in 3 children with restless sleep disorder. J Clin Sleep Med. 2023;19(3):633-637.

Attention deficit hyperactivity disorder and restless leg syndrome across the lifespan: A systematic review and meta-analysis

This systematic review aims to assess the association between attention deficit hyperactivity disorder (ADHD) and restless legs syndrome (RLS) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Databases were searched for original articles that reported prevalence data on ADHD and RLS until January 24th, 2023. Two independent reviewers evaluated the quality of the articles using the National Institutes of Health assessment tool. Among the 208 articles identified between 1996 and 2022, 29 were included. In large general population studies, 2.6-15.3% of participants met the RLS criteria, of which 3.2-17.4% presented with ADHD. In the ADHD group, RLS symptoms ranged from 11 to 42.9% in children and 20-33.0% in adults. This suggests a strong co-occurrence between RLS and ADHD. A common characteristic of these conditions is sleep fragmentation, as discussed in the reviewed papers. Although large-scale studies with comparable diagnostic criteria across the lifespan are required, our findings may advocate a possible common physiological pathway, including sleep fragmentation and dopaminergic system impairment.

Polysomnographic versus video scoring of large muscle group movements during sleep in children with restless sleep

BACKGROUND

Restless sleep is a common complaint in children with sleep and other disorders, when it occurs as an isolated symptom it can depict a separate condition called restless sleep disorder (RSD). A key diagnostic feature of RSD is the polysomnographic (PSG) scoring of five or more large muscle movements (LMM) per hour of sleep. Initial publications on RSD used video-PSG (vPSG) analysis to count LMM. However, recently, scoring criteria for LMM on PSG signals alone have been published, but their correlation with vPSG scoring has not been done. In this study we compare vPSG to PSG scoring of LMM in a group of children with restless sleep.

METHODS

Video-PSG studies from 20 children (14 boys and six girls, mean age 11.3 years, SD 4.17) were reviewed by a blinded scorer. First, scorer used a video analysis (video-LMM), then on a different day the scorer used PSG criteria for LMM without video (PSG-LMM).

RESULTS

PSG-LMM were found to be significantly more numerous than video-LMM (mean LMM index 8.6 ± 2.95 SD vs. 6.9 ± 2.40 SD, respectively) while their duration was not statistically different (mean LMM duration 11.6 ± 2.33 s vs. 11.6 ± 2.99 s, respectively). 95.4% of video-LMM were also detected by PSG. Both LMM indexes and durations obtained by the two methods correlated significantly between them. A cut off of 6.24 LMM/hour by PSG-LMM was calculated to be equivalent to 5 LMM by video-LMM.

CONCLUSIONS

PSG-LMM scoring criteria detects >95% of LLM scored by video-PSG. PSG-LMM lead to the detection of a higher number of movements, indicating their higher sensitivity in picking up LMM in PSG recording. This further supports that these criteria need adequate consideration for their eventual inclusion into the current sleep scoring manual. A higher index may be needed to diagnose RSD.

Sleep Bruxism Contributes to Motor Activity Increase during Sleep in Apneic and Nonapneic Patients-A Polysomnographic Study

Background: Jaw motor activity (MA) in sleep bruxism (SB) has been demonstrated to accompany lower limb movements. However, it remains unknown whether SB activity coexists with other types of movements and what the possible underlying mechanisms of such temporal coexistence are. In obstructive sleep apnea (OSA), increased movement activity is also reported, including SB activity; however, no studies have compared MA in apneic and nonapneic SB patients. Aim: This cross-sectional study focused on the phenomenon of “big body movements” in patients with either SB or OSA (or both) and intended to identify the primary factors contributing to their appearance, using polysomnography (PSG) recording. Methods: A whole-night videoPSG was carried out in 287 participants, and 124 apneic and 146 nonapneic participants were selected for the study. In both groups, participants were further divided into no SB, moderate SB, and severe SB (SSB) subgroups based on their bruxism episode index (BEI). MA was recorded using a built-in sensor of the central PSG unit located on the participant’s chest during the examination. Results: The presence of SB was related to the higher intensity of MA in both apneic and nonapneic participants, though in general the MA level was higher in apneic participants, with the highest level observed in SSB apneic participants. Conclusions: SB might contribute to MA. The prevalence of SB might be higher in nonapneic patients due to phasic and mixed SB activity, whereas the SB phenotype seems to be less relevant in apneic patients. SB activity is likely to increase MA in non-REM 1 sleep.

Restless sleep disorder, restless legs syndrome, and periodic limb movement disorder-Sleep in motion!

Sleep-related movement disorders (SRMDs) represent an important part of pediatric sleep disorders. The most common complaint in SRMD is restless sleep at night. Restless sleep is reported in up to 80% of children with restless legs syndrome (RLS) and children with periodic limb movements of sleep (PLMS) disorder (PLMD). However, restless sleep causing daytime behavioral consequences can be seen in children without another apparent condition and has recently been identified as a new independent primary pediatric sleep disorder, called restless sleep disorder (RSD). This study describes these three main SRMDs (RSD, RLS, and PLMD), explains the new consensus criteria for RSD, emphasizes the rapidly evolving areas of research in this field, and proposes recommendations for future research. In particular, the published data constitute convincing evidence that sleep-related movements are disruptors of sleep quality and continuity. However, while important advancements have recently been reported in adults, a detailed analysis of the phenomenology and consequences of sleep-related movements has just started in children. New approaches, standardized diagnostic methods, and specific guidelines are needed in the field of pediatric SRMD.

Restless Sleep Disorder (RSD): a New Sleep Disorder in Children. A Rapid Review

PURPOSE OF REVIEW

Restless sleep disorder (RSD) is a recently identified pediatric sleep disorder characterized by frequent movements during sleep associated with daytime symptoms. In this review we summarize the expanding evidence of the clinical presentation of RSD, potential pathophysiology, associated comorbidities, and current treatment options that will help the pediatrician identify children with RSD in a timely manner.

RECENT FINDINGS

RSD is diagnosed in 7.7% of children referred evaluated in a pediatric sleep center. Children with RSD present with frequent nightly movements during sleep for at least 3 months, and have daytime symptoms related to poor sleep quality including excessive sleepiness, hyperactivity, irritability among other symptoms. Current evidence shows an increased sympathetic predominance, increased NREM sleep instability, and iron deficiency, as well as increased prevalence in parasomnias and attention deficit hyperactivity disorder. Consensus diagnostic criteria were recently published to diagnose RSD and emergent evidence suggests that iron supplementation improves its nighttime and daytime symptoms.

Large body movements on video polysomnography are associated with daytime dysfunction in children with restless sleep disorder

Restless sleep disorder (RSD) is a newly defined sleep-related movement disorder characterized by large muscle movements (LMM) in sleep. We examined the sleep study, clinical characteristics, and daytime functioning in children with RSD and compared them to children with periodic limb movement disorder (PLMD) or restless legs syndrome (RLS). Video polysomnography from 47 children with restless sleep was retrospectively reviewed for LMM and age- and sex-matched to 34 children with PLMD and 12 children with RLS. Data examined included PSG characteristics, ferritin, Pediatric Quality of Life (PedsQL), and Epworth Sleepiness Scale (ESS). Fourteen children met the clinical criteria for RSD with an LMM index of 5 or more per hour of sleep. Mean ESS was elevated in patients with RSD compared to either the PLMD or RLS groups though the result did not reach statistical significance (RSD = 10.20 ± 6.81, PLMD = 6.19 ± 4.14, RLS = 6.25 ± 4.90). The PedsQL score was significantly decreased in the RLS group compared to RSD and was reduced overall in all three groups (PedsQL Total RSD = 70.76 ± 18.05, PLMD = 57.05 ± 20.33, RLS = 53.24 ± 16.97). Serum ferritin values were similar in all three groups (RSD = 26.89 ± 10.29, PLMD = 33.91 ± 20.31, RLS = 23.69 ± 12.94 ng/mL, p = ns). Children with RSD demonstrate increased daytime sleepiness compared to PLMD or RLS and all three disease groups showed decreased quality of life. Further studies are needed to examine long-term consequences of RSD.

Evaluation of movement and brain activity

Clinical neurophysiology studies can contribute important information about the physiology of human movement and the pathophysiology and diagnosis of different movement disorders. Some techniques can be accomplished in a routine clinical neurophysiology laboratory and others require some special equipment. This review, initiating a series of articles on this topic, focuses on the methods and techniques. The methods reviewed include EMG, EEG, MEG, evoked potentials, coherence, accelerometry, posturography (balance), gait, and sleep studies. Functional MRI (fMRI) is also reviewed as a physiological method that can be used independently or together with other methods. A few applications to patients with movement disorders are discussed as examples, but the detailed applications will be the subject of other articles.

Restless sleep disorder in children with NREM parasomnias

STUDY OBJECTIVES

Restless sleep disorder (RSD) is a newly defined sleep disorder in the pediatric age group. Here, we investigated the frequency of RSD and the sleep characteristics in children with NREM (non-rapid eye movements) parasomnias associated with RSD.

METHODS

We analyzed all patients with NREM parasomnias for the last 1 year, and investigated the clinical and polysomnographic characteristics.

RESULTS

Twenty-eight children with NREM parasomnias and age- and gender-matched 20 healthy children were analyzed. The diagnosis of RSD was made in eight children with NREM parasomnias (28.6%), and none of the children had RSD in controls (p = 0.008). The most common diagnosis among children with RSD was somnambulism (six children), but not significantly (p = 0.308). Sleep efficiency was lower in children with RSD than those without RSD (p = 0.033). In cyclic alternating pattern analysis (CAP), CAP rate, durations and the indices of phases A1, A2, and A3 were significantly higher in children with NREM parasomnias in compared to controls. CAP parameters between children with or without RSD; however, were similar, except for higher index of phase A3 in children with RSD, suggesting arousal reactions accompanying RSD.

CONCLUSIONS

We demonstrated that RSD was present in almost one third of the children with NREM parasomnias. Sleep quality was worse in children with NREM parasomnias and RSD. An increase in sleep instability compatible with NREM parasomnia was present, while an increased phase A3 in RSD was remarkable. RSD is associated with a worse sleep quality and increased arousals, and should be questioned in children with NREM parasomnias.

Restless Sleep Disorder

Restless sleep disorder is (RSD) a condition characterized by frequent large movements during sleep associated with daytime impairment. RSD has been studied in children aged 6 to 18 years. Polysomnography is necessary for the diagnosis of RSD. The current diagnostic criteria include more than 5 large movements per hour of sleep documented by PSG. The pathophysiology is not known yet, but iron deficiency and sleep instability and increased sympathetic activation are suspected to play a role. Iron supplementation is the only treatment option studied so far.

Sleep spindles in children with restless sleep disorder, restless legs syndrome and normal controls

OBJECTIVE

To analyze and identify differences in sleep spindles in children with restless sleep disorder (RSD), restless legs syndrome (RLS) and normal controls.

METHODS

PSG (polysomnography) from children with RSD, RLS and normal controls were analyzed. Sleep spindle activity was detected on one frontal and one central electrode, for each epoch of N2 and N3 sleep. Sleep spindle density, duration and intensity (density × duration) were then obtained and used for analysis.

RESULTS

Thirty-eight children with RSD, twenty-three children with RLS and twenty-nine controls were included. The duration of frontal spindles in sleep stage N2 was longer in children with RSD than in controls. Frontal spindle density and intensity tended to be increased in RSD children. No significant differences were found for central spindles.

CONCLUSION

Children with RSD had longer frontal spindles. This finding may contribute to explain the occurrence of excessive movement activity during sleep and the presence of daytime symptoms.

SIGNIFICANCE

Recent research has demonstrated that children with RSD have increased NREM instability and sympathetic activation during sleep. Analyzing sleep spindles in children with RSD in comparison with children with RLS and controls adds to our understanding of the pathophysiology or RSD and its effects on daytime impairment.

Scoring of large muscle group movements during sleep: An International Restless Legs Syndrome Study Group (IRLSSG) position statement

There is a gap in the manuals for scoring sleep-related movements because of the absence of rules for scoring large movements. A taskforce of the International Restless Legs Syndrome Study Group elaborated rules that define the detection and quantification of movements involving large muscle groups. Consensus on each of the criteria in this paper was reached by testing the presence of consensus on a first proposal; if no consensus was achieved, the concerns were considered and used to modify the proposal. This process was iterated until consensus was reached. A preliminary analysis of the duration of movements involving large muscle groups was also carried out on data from two previous studies, which, however, used a visual analysis of video-polysomnographic recordings obtained from children or adults. Technical specifications and scoring rules were designed for the detection and quantification of large muscle group movements during sleep with a duration between 3 and 45 s in adults or 3 and 30 s in children, characterized by an increase in electromyographic activity and/or the occurrence of movement artifact in any combination of at least two recommended channels and not meeting the criteria for any other type of movement. Large muscle group movements are often accompanied by sleep stage changes, arousals, awakenings, and heart rate rises. The absence of clear and detailed rules defining them has likely impeded the development of studies that might disclose their clinical relevance; these new rules fill this gap.

Restless sleep in children: A systematic review

This systematic review assessed the prevalence of restless sleep in children, documented the association of restless sleep with other conditions, and summarized the existing evidence regarding whether restless sleep should be considered a distinct sleep disorder. A comprehensive search of electronic databases was performed using the broad search term "restless sleep" in all fields. Of the 266 articles retrieved, 107 were retained for inclusion in this review. The majority (n = 93) were observational studies. The studies were grouped under several pathologic/condition categories: sleep-disordered breathing (n = 19); adenotonsillectomy (n = 7); respiratory disorders, otitis media, and smoke exposure (n = 12); sleep-related movement disorders and restless sleep disorder (n = 11); neurologic or psychiatric disorders (n = 7); Down syndrome/other neurodevelopmental disorders (n = 10); sleep-related bruxism and other sleep disorders (n = 7); and restless sleep in the general population/mixed clinical samples (n = 18). A high prevalence of restless sleep was found in children with many of these underlying conditions, likely related to associated inherent sleep disruption and frequent awakenings (e.g., apnea and periodic limb movements), pain, sleep instability, and caregiver perception. The majority of studies identified restless sleep as reported by the caregiver, only 34 studies attempted to define restless sleep further. Four studies provided supportive evidence for designating restless sleep as an independent sleep disorder, restless sleep disorder (RSD). This review highlights the fact that the prevalence, etiology and sequelae (including daytime impairments) of restless sleep in children are important topics deserving of further research and that clinical definitions based on empirical evidence need to be developed. The designation of "primary" versus "secondary" restless sleep may be a useful construct, especially with regard to developing clinical trials and treatment algorithms.