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Sleep is an integral and vital component of human life, contributing significantly to overall health and well-being, but a considerable number of people worldwide experience sleep disorders. Sleep disorder diagnosis heavily depends on accurately classifying sleep stages. Traditionally, this classification has been performed manually by trained sleep technologists that visually inspect polysomnography records. However, in order to mitigate the labor-intensive nature of this process, automated approaches have been developed. These automated methods aim to streamline and facilitate sleep stage classification. This study aims to classify sleep stages in a dataset comprising subjects with insomnia, PLM, and sleep apnea. The dataset consists of PSG recordings from the multi-ethnic study of atherosclerosis (MESA) cohort of the national sleep research resource (NSRR), including 2056 subjects. Among these subjects, 130 have insomnia, 39 suffer from PLM, 156 have sleep apnea, and the remaining 1731 are classified as good sleepers. This study proposes an automated computerized technique to classify sleep stages, developing a machine-learning model with explainable artificial intelligence (XAI) capabilities using wavelet-based Hjorth parameters. An optimal biorthogonal wavelet filter bank (BOWFB) has been employed to extract subbands (SBs) from 30 seconds of electroencephalogram (EEG) epochs. Three EEG channels, namely: Fz_Cz, Cz_Oz, and C4_M1, are employed to yield an optimum outcome. The Hjorth parameters extracted from SBs were then fed to different machine learning algorithms. To gain an understanding of the model, in this study, we used SHAP (Shapley Additive explanations) method. For subjects suffering from the aforementioned diseases, the model utilized features derived from all channels and employed an ensembled bagged trees (EnBT) classifier. The highest accuracy of 86.8%, 87.3%, 85.0%, 84.5%, and 83.8% is obtained for the insomniac, PLM, apniac, good sleepers and complete datasets, respectively. Using these techniques and datasets, the study aims to enhance sleep stage classification accuracy and improve understanding of sleep disorders such as insomnia, PLM, and sleep apnea., Competing Interests: Declaration of Competing Interest None., (Copyright © 2024 IPEM. Published by Elsevier Ltd. All rights reserved.)

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., Competing Interests: Declaration of competing interest The authors report no conflicts of interest. This was not an industry-supported project., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Purpose: Patients with early onset scoliosis are at high risk of sleep disordered breathing, sleep disruption, and adverse consequences of poor sleep. In this study, we aim to assess the prevalence of periodic limb movements of sleep in a cohort of children with early onset scoliosis and identify factors that correlate with the presence of periodic limb movements., Methods: This is a retrospective chart review of 40 patients with EOS (ages 1-17 years) who underwent a PSG from 2003 through 2019. Data collected included age, sex, and polysomnography parameters. Descriptive statistics were used: independent T test and Pearson correlation., Results: The average age was 9.6 years (SD 5.2); 22 were female. Eleven patients (27.5%) had elevated periodic limb movement index (PLMI) (≥ 5). Those with PLMI ≥ 5 had arousal index of 15.4 (SD 7.2) and those with normal PLMI having an arousal index of 9.4 (SD 4.9); this reached statistical significance (p < 0.05). Those with elevated PLMI spent 4.9 (SD 8.3) minutes with saturations below 88%, while those with normal PLMI spent 1.0 (SD 1.8); this was statistically significant. There was a moderate positive correlation between arousal index, hypoxemia, and PLMI., Conclusion: The study suggests that children with early onset scoliosis have higher frequency of periodic limb movements during sleep, and these may be correlated with increased arousal and with hypoxemia., (© 2024. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Obstructive sleep apnea is a well-established risk factor for cardiovascular disease (CVD). Recent studies have also linked periodic limb movements during sleep to CVD. We aimed to determine whether periodic limb movements during sleep and obstructive sleep apnea are independent or synergistic factors for CVD events or death., Methods and Results: We examined data from 1049 US veterans with an apnea-hypopnea index (AHI) <30 events/hour. The primary outcome was incident CVD or death. Cox proportional hazards regression assessed the relationships between the AHI, periodic limb movement index (PLMI), and the AHI×PLMI interaction with the primary outcome. We then examined whether AHI and PLMI were associated with primary outcome after adjustment for age, sex, race and ethnicity, obesity, baseline risk of mortality, and Charlson Comorbidity Index. During a median follow-up of 5.1 years, 237 of 1049 participants developed incident CVD or died. Unadjusted analyses showed an increased risk of the primary outcome with every 10-event/hour increase in PLMI (hazard ratio [HR], 1.08 [95% CI, 1.05-1.13]) and AHI (HR, 1.17 [95% CI, 1.01- 1.37]). Assessment associations of AHI and PLMI and their interaction with the primary outcome revealed no significant interaction between PLMI and AHI. In fully adjusted analyses, PLMI, but not AHI, was associated with an increased risk of primary outcome: HR of 1.05 (95% CI, 1.00-1.09) per every 10 events/hour. Results were similar after adjusting with Framingham risk score., Conclusions: Our study revealed periodic limb movements during sleep as a risk factor for incident CVD or death among those who had AHI <30 events/hour, without synergistic association between periodic limb movements during sleep and obstructive sleep apnea.

Periodic limb movement disorder (PLMD) is a condition in which patients experience frequent periodic limb movements of sleep (PLMS). Synchronized arousal responses cause sleep fragmentation, resulting in insomnia, daytime sleepiness, and fatigue. A 59-year-old man was identified as having intense sleep-talking and body movements, suggesting rapid eye movement (REM) sleep behavior disorder (RBD). Attended video-polysomnography (PSG) revealed that sleep-talking and body movements occurred only during non-REM sleep and were associated with PLMS-induced arousals (periodic leg movement arousal index, 53.2/h). Pramipexole administration improved events during sleep and daytime sleepiness, and the PSG findings and clinical course led to a diagnosis of PLMD. This case demonstrates that PLMD mimics the symptoms of RBD and that a detailed analysis of monitored video PSG is crucial to confirm the diagnosis of RBD and to identify or exclude other causes of sleep talking and behavior.

During sleep, the lower extremities exhibit periodic repetitive movements which are referred to as Period Limb Movement (PLM). Polysomnography (PSG) is the gold standard for diagnosing periodic limb movement disorder. The frequency of PLM episodes per hour of sleep (PLMI) determines the severity of the condition. PLM are generated by a dynamic process, however PLMI measures only the average PLM rate and does not capture the dynamic properties of PLM. Here, we characterise PLM dynamics using a generalised dynamic model as a function of sleep stage, timing of past PLM events and adjacent sleep disordered-breathing events. We analysed PSG recordings of 237 men and 222 women enrolled in the Multi-ethnic Study of Atherosclerosis (MESA) dataset to model dynamic PLM features. We statistically analysed whether these dynamics are associated with sex, age, and BMI. Modelling suggests instantaneous PLM rates are greater in men than women and higher in N1 and N2 non-rapid eye movement sleep than N3 and rapid eye movement sleep. The generalised model constitutes statistically robust approach towards the characterisation of periodic limb movement.Clinical Relevance- The generalised model may enable differentiated diagnostics of periodic limb movement disorder.

Study Objectives: To address the hypothesis that periodic leg movements during sleep (PLMS) are more frequent in children with attention-deficit hyperactivity disorder (ADHD) when compared with typically developing (TD) children. To that end, we analyzed PLMS in a recent case-control study and conducted a systematic review and meta-analysis of PLMS frequency in children with ADHD and TD children., Methods: In our case-control study, we compared the PLMS frequency of 24 children with ADHD (mean age 11 years, 17 males) to that of 22 age-matched typically developing (TD) children (mean age 10 years, 12 males). A subsequent meta-analysis included 33 studies that described PLMS frequency in groups of children with ADHD and/or groups of TD children., Results: The case-control study did not show any differences in the frequency of PLMS between children with ADHD and TD children, a result that was consistent across a range of different definitions of PLMS, which in turn had a significant and systematic effect on PLMS frequency. The meta-analysis compared the average PLMS indices and the proportion of children with elevated PLMS indices between children with ADHD and TD children and across a number of analyses did not find any meta-analytic results that supported the hypothesis that PLMS are more frequent in children with ADHD., Conclusions: Our results suggest that PLMS are not more frequent in children with ADHD compared with TD children. A finding of frequent PLMS in a child with ADHD should therefore be considered a separate disorder and prompt specific diagnostic and therapeutic strategies., (© The Author(s) 2023. Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: To determine the predictive role of periodic limb movements in sleep (PLMS) in cerebral small vessel disease (cSVD) progression rate., Material and Methods: Fifty patients with cSVD, aged 60-75 y.o., were enrolled. The study protocol included MRI assessment of white matter hyperintensities (WMH), nocturnal actigraphy and cognitive assessment. Depending on the PLMS, the main (PLM index ≥15) and the control (PLM index <15) groups were formed. The second visit was carried out in one year follow-up period, the examination consisted of brain MRI and cognitive assessment under the same protocol. ANCOVA was performed to determine if PLMS influence the degree of MRI- and neuropsychological changes., Results: A significant effect of PLMS on the increase in the volume of WMH was revealed, both in the form of an increase in the index by more than 15 movements per hour ( p =0.03), and quantitatively in the form of a connection with the index value ( p =0.048). The influence of PLMS on the progression of cognitive dysfunction has not been found, however, it has been shown that the presence of PLMS is associated with lesions in the deep white matter ( r =0.42, p <0.0001), and the results of neuropsychological tests are associated with lesions in the periventricular and juxtacortical WMH ( p < 0.05 for each test)., Conclusion: PLMS predict WMH progression in cSVD.

Restless sleep disorder (RSD) is a condition recently described by a group of sleep experts who developed diagnostic and polysomnographic criteria after conducting a comprehensive review of the available literature where poor sleep or restless sleep is a symptom alone or that accompanies other disorders. This group defined RSD as a condition characterized by parental complaints of frequent jerking movements during sleep, position changes, and sleep disruption that cause significant impairment during the day. Diagnostic criteria include the presence of symptoms for at least 3 months, 3 times a week, and at least 5 movements per hour on polysomnography. Changes in behavior during the day, such as drowsiness, irritability, and hyperactivity that are not explained by a medical, pharmacological, or behavioral condition, should be considered. Its estimated prevalence is 7.7% of children referred for sleep problems. Children often have ferritin levels below 50 µg/l, a point in common with restless legs syndrome. Treatment consists of iron supplements, which have shown benefits in these children. To establish the diagnosis, secondary symptoms of medical origin or other sleep disorders such as restless legs syndrome or periodic limb movement disorder must be ruled out. The objective of this report is to review the current recommendations on this entity, describe the clinical, pathophysiological, and polysomnographic keys, in order to highlight the need to publicize this condition and expand studies in age groups other than those already defined and to generate treatment guidelines.

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., (© 2021 Wiley Periodicals LLC.)

Although periodic limb movement during sleep (PLMS) and restless legs syndrome (RLS) are common in children and adolescents, they are relatively overlooked as a target of treatment. PLMS has been evaluated as having a lower clinical significance than RLS. This study examined the relationship of socio-behavioral factors of PLMS in Korean adolescents and checked whether PLMS is associated with excessive daytime sleepiness (EDS), depending on whether restless legs symptoms accompany it. In a cross-sectional study, 25,789 adolescents between 12 and 18 years of age (15.76 ± 1.73 years; female 51.49%) were evaluated using an online survey. Various self-report questionnaires were used to assess PLMS and RLS symptoms, EDS, sleep habits, and various socio-behavioral factors. The prevalence of self-perceived PLMS and restless legs symptoms were 903 (3.50%) and 1311 (5.08%), respectively. Of the 1311 participants, 399 had self-perceived PLMS. The odds ratios (ORs) for self-perceived PLMS in participants with restless legs symptoms were: males (OR = 1.528; 95% CI: 1.145-2.040), usually/always experienced apnea apnea (OR, 3.006; 95% CI, 1.954-4.624), increased proneness to Internet addiction (OR = 1.013; 95% CI: 1.001-1.025), sometimes/often consuming coffee (OR = 1.312; 95% CI: 1.015-1.695), EDS (OR = 0.826; 95% CI: 0.488-1.398), and perceived insufficient sleep (OR = 1.143; 95% CI: 0.835-1.565). The male gender, witness apnea, consuming coffee, and being prone to Internet addiction were identified as factors significantly associated with self-perceived PLMS in participants with restless legs symptoms. However, EDS and insufficient sleep were associated with self-perceived PLMS in the absence of restless legs symptoms.

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., (© The Author(s) 2022. Published by Oxford University Press on behalf of Sleep Research Society. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Study Objectives: To assess the frequency of restless legs syndrome (RLS), periodic limb movements during sleep (PLMS), and their overlap in a large sample of patients with multiple sclerosis (MS). To compare clinical and paraclinical findings among four subgroups of patients: RLS-/PLMS- (patients without RLS and PLMS), RLS+/PLMS- (patients with RLS and without PLMS), RLS-/PLMS (patients without RLS and with PLMS), and RLS+/PLMS+ (patients with both RLS and PLMS)., Methods: In this cross-sectional, observational, instrumental study, 86 patients (M/F: 27/59; mean age 48.0 ± 10.8 years) with a diagnosis of MS underwent a telephone interview assessing the five standard diagnostic criteria for RLS. Seventy-six participants underwent polysomnography (PSG) and maintenance of wakefulness test (MWT). Instrumental and clinical findings were subsequently statistically compared to investigate their association with RLS and PLMS index (PLMSI)., Results: RLS and PLMS (PLMSI ≥15/h) frequency in patients with MS were of 31.4% and 31.6%, respectively. Among patients with RLS, 37.5% had a PLMSI of at least 15/h. RLS-/PLMS+ group showed higher wake after sleep onset (p = 0.01), stage shifts per hour (p = 0.03), increased stage N1 (p = 0.03), and reduction in stage N3 (p = 0.01) compared to RLS-/PLMS-. RLS had no influence on clinical and PSG parameters (p = 0.45)., Conclusions: RLS is highly frequent in patients with MS. The frequency of PLMS is comparable to the general population. The low percentage of patients with RLS having a high PLMSI, together with the absence of correlation between RLS and female gender and older age, supports the existence of a distinct symptomatic form of RLS in MS., (© Sleep Research Society 2021. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Purpose: Cyclic alternating pattern (CAP) is known to increase in many conditions of sleep disruption and sleep disorders, including obstructive sleep apnea syndrome and periodic limb movements in sleep (PLMS). Periodic limb movements in sleep associated with obstructive sleep apnea syndrome may vanish after positive airway pressure treatment, may persist, or emerge at treatment night. Here, the authors aimed to investigate the underlying pathophysiology of nonvanishing, vanishing, or newly emergent PLMS., Methods: The authors designed a prospective study and included 10 patients with nonvanishing PLMS during positive airway pressure therapy, 10 patients with vanishing PLMS, 10 patients with newly emergent PLMS, and 10 patients without PLMS at both nights. The CAP analysis was performed in detail at diagnostic polysomnography recording and at positive airway pressure titration. The changes in CAP parameters were evaluated in regard to nonvanishing, vanishing, or newly emergent PLMS., Results: Periodic limb movements in sleep related to A1 subtype of CAP were observed to decrease under positive airway pressure titration more than PLMS related to A3 subtype of CAP. The A3 subtype of CAP was higher in patients with vanishing PLMS than those with newly emergent PLMS. The newly emergent PLMS were mostly related to A1 subtype of CAP compared with A3 subtype of CAP., Conclusions: This study showed that vanishing, nonvanishing, or newly emerging PLMS may indeed represent different underlying pathophysiology. The authors suggest that organization of sleep and preservation of ultradian rhythms during titration may determine whether PLMS will be vanished or persist. Newly emergent PLMS may probably arise from a separate central generator by the activation of higher cortical areas., Competing Interests: The authors have no funding or conflicts of interest to disclose., (Copyright © 2020 by the American Clinical Neurophysiology Society.)

Periodic leg movements during sleep (PLMS) are a frequent finding in nocturnal sleep registrations that include tibialis anterior electromyographic signals. Different PLMS scoring rules exist and can have a major impact on PLMS frequency, which tends to be underappreciated. There is no consistent evidence that frequent PLMS are a causal risk factor for clinically significant outcomes. Several critical open questions are identified that need to be addressed, including but not limited to the consideration of the full range of all sleep-related leg movement activity., Competing Interests: Disclosure Dr S. Fulda is supported by Swiss National Science Foundation (SNSF) grants No. 320030-160009 and 320030-179194., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Purpose: This study evaluates the differences in periodic leg movement (PLM) rates for Restless Legs Syndrome (RLS) and healthy controls when using the updated PLM scoring criteria developed by IRLSSG in 2016 versus the prior PLM scoring criteria developed by IRLSSG in 2006. Four major problems with the prior standards had been objectively identified, i.e. minimum inter-movement interval should be 10 not 5 s, non-PLM leg movements should end any preceding PLM sequence, a leg movement (LM) can be any length > 0.5 s, and a PLM should be a persisting movement not a couple or a series of closely spaced, very brief events. Each of these led to including, erroneously, various random leg movements as PLM. Correcting these problems was expected to increase specificity, reducing the number of PLM detected, particularly in situations producing relatively more random leg movements, e.g. wake vs. sleep and controls without PLMD vs. RLS patients., Methods: This study evaluated the putative benefits of the updated, 2016-scoring criteria. The LMs from 42 RLS patients and 30 age- and gender-matched controls were scored for PLMS and PLMW from standard all-night PSG recordings using both 2006 and 2016 WASM criteria., Results/conclusion: The results confirmed that that the 2016 compared to the 2006 criteria generally decreased the PLM rates with particularly large decreases for the conditions with more random non-PLM events, e.g. wake times and normal healthy controls. This supported the view that the new criteria succeeded in increasing the specificity of PLM detection. Moreover, the changes in PLM rates were generally small for the conditions with relatively few random LM, e.g. RLS and sleep. Thus the bulk of existing PLMS research does not require reconsideration of results, with possible exception of special situations with relatively more random leg movements than periodic leg movements, e.g. wake, healthy normals and children.

Purpose of Review: In this article, the different sleep-related movement disorders are discussed with special attention given to restless legs syndrome (RLS)., Recent Findings: The differential diagnosis of sleep-related movement disorders can often be challenging; therefore, it is essential to have accurate information to make a correct diagnosis. This article focuses on RLS, highlighting the change in the paradigm of initial treatment, the role played by iron (pathophysiologic and therapeutic), and how to approach possible complications occurring with long-term treatment., Summary: RLS is one of the most common neurologic conditions, and it is common in clinical practice to find patients experiencing symptoms suggestive of RLS. Neurologists must be careful and thorough in the diagnosis, excluding RLS mimics. The decisions regarding which specific sleep-related movement disorder is present and how it should be treated are important because in certain cases, especially in RLS, adverse effects and long-term complications are frequently reported with the use of certain drugs.

Purpose: Sleep disturbances are common in Alzheimer's disease (AD) and mild cognitive impairment (MCI) patients. Non-rapid eye movement stage 3 (N3), rapid eye movement stage (REM), spindle density, and K-complex (KC) density are decreased in MCI and AD patients. Periodic limb movements in sleep (PLMS) are increased in other neurodegenerative diseases. We aimed to distinguish amnestic mild cognitive impairment (aMCI) patients from the overall population of MCI patients by comparing the N3 and REM proportions, the morphological characteristics of spindles and KCs and the periodic limb movement index (PLMI) among control, aMCI and AD subjects., Methods: In 92 subjects (30 controls, 32 aMCI and 30 AD), sleep stages, spindles, KCs and PLMS were recorded during the second of two nights of polysomnography (PSG). We compared the above parameters among the three groups., Results: AD and aMCI subjects had lower proportions of N3 and REM, poorer spindle and KC activities and more frequent PLMS than controls. These alterations were associated with decreased Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. We determined cut-off values for distinguishing aMCI and AD using logistic regression and receiver operating characteristic (ROC) analyses., Conclusions: AD and aMCI patients have abnormal sleep stage proportions, spindles, KCs and PLMS. The combination of the above alterations may distinguish aMCI and AD patients from controls with high specificity and sensitivity.

Objective: Currently, manual scoring is the gold standard of leg movement scoring (LMs) and periodic LMs (PLMS) in overnight polysomnography (PSG) studies, which is subject to inter-scorer variability. The objective of this study is to design and validate an end-to-end deep learning system for the automatic scoring of LMs and PLMS in sleep., Methods: The deep learning system was developed, validated and tested, with respect to manual annotations by expert technicians on 800 overnight PSGs using a leg electromyography channel. The study includes data from three cohorts, namely, the Wisconsin Sleep Cohort (WSC), Stanford Sleep Cohort (SSC) and MrOS Sleep Study. The performance of the system was further compared against individual expert technicians and existing PLM detectors., Results: The system achieved an F1 score of 0.83, 0.71, and 0.77 for the WSC, SSC, and an ancillary study (Osteoporotic Fractures in Men Study, MrOS) cohorts, respectively. In a total of 60 PSGs from the WSC and the SSC scored by nine expert technicians, the system performed better than two and comparable to seven of the individual scorers with respect to a majority-voting consensus of the remaining scorers. In 60 PSGs from the WSC scored accurately for PLMS, the system outperformed four previous PLM detectors, which were all evaluated on the same data, with an F1 score of 0.85., Conclusions: The proposed system performs better or comparable to individual expert technicians while outperforming previous automatic detectors. Thereby, the study validates fully automatic methods for scoring LMs in sleep., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Study Objectives: Little is known about comorbidities in children who have elevated periodic limb movement index (PLMI) during overnight polysomnogram (PSG). The aim of this study is to identify comorbidities in children with elevated PLMI (PLMI > 5) versus children with PLMI < 5 presenting to a pediatric sleep center., Methods: This study was a retrospective review of all clinically indicated PSGs obtained consecutively from 3/2017-3/2019 at Seattle Children's Sleep Disorders Center. Data collected included demographics, clinical presentation, medications, medical history, family history specifically for restless legs syndrome (RLS), ferritin levels, and PSG metrics. Characteristics between those with (cases) elevated PLMI (AASM criteria) and without (controls) were summarized., Results: We identified 148 subjects with elevated PLMI (67% male, mean age 7.95 years, range 1-20), yielding a PLMI > 5 prevalence of 5%. There were 188 controls included (58% male, mean age 8.0 years, range 1-19). Neither sex (chi-square = 2.8, NS) nor age (Mann-Whitney U = 1339.5, NS) differed between groups. Case subjects had a higher prevalence of RLS, snoring, insomnia, mood disorders, behavioral problems, morning headaches, chronic kidney disease, epilepsy, and chronic heart disease. Similarly, the use of antidepressants, antipsychotics, antiseizure medication, and other medications was statistically more frequent in children with elevated PLMS. The prevalence of PLMI > 5 was 5% and the prevalence of periodic limb movement disorder (PLMD) was 0.3% in children referred to polysomnography. Ferritin levels did not differ., Conclusions: We identified the prevalence of PLMD in a sleep medicine-referred population. We have also identified comorbidities and medications associated with elevated PLMI in children.No clinical trial., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Background: Evidence of the relationship between periodic limb movements during sleep (PLMS) and cerebral small vessel disease (cSVD) is limited and inconsistent. Here, we aimed to assess the independent association between PLMS and the different neuroimaging signatures of cSVD., Methods: Atahualpa residents aged more than or equal to 60 years enrolled in the Atahualpa Project undergoing polysomnography and MRI with time intervals less than or equal to 6 months were included. MRI readings focused on white matter hyperintensities (WMH) of presumed vascular origin, deep cerebral microbleeds (CMB), silent lacunar infarcts (LI), and more than 10 enlarged basal ganglia-perivascular spaces (BG-PVS). Data from single-night polysomnograms were interpreted according to recommendations of the American Academy of Sleep Medicine. Associations between the PLMS index and neuroimaging signatures of cSVD (as dependent variables) were assessed by means of logistic regression models, adjusted for relevant confounders., Results: A total of 146 individuals (mean age: 71.4 ± 7.5 years; 64% women) were included. A PLMS index more than or equal to 15 per hour were noted in 48 (33%) participants. Moderate-to-severe WMH were present in 33 individuals (23%), deep CMB in 9 (6%), silent LI in 16 (11%), and more than 10 BG-PVS in 44 (30%). In univariate analyses, silent LI (P = .035) and the presence of more than 10 enlarged BG-PVS (P = .034) were significantly higher among participants with a PLMS index more than or equal to 15 per hour. However, fully-adjusted multivariate models showed no significant association between PLMS index more than or equal to 15 per hour and any of the neuroimaging signatures of cSVD., Conclusions: This study shows no independent association between the PLMS index and neuroimaging signatures of cSVD in stroke-free community-dwelling older adults., (Copyright © 2019 Elsevier Inc. All rights reserved.)

None: Sleep disorders are prevalent in patients with end-stage renal disease (ESRD). In those patients on nocturnal dialysis, it is important to perform objective sleep assessment during regular dialysis. We present the case of a man on continuous cycler peritoneal dialysis with disabling fatigue and moderate restless legs syndrome (RLS). Actigraphy demonstrated excessive nocturnal movement. Unattended home polysomnography, performed during his regular peritoneal dialysis, confirmed frequent nocturnal periodic limb movements with disturbed sleep. Treatment with low dose pramipexole led to improved RLS and marked improvement in his energy. Clinicians caring for patients with ESRD should have a low threshold for objective sleep assessment given that sleep disorders are common, disabling and eminently amenable to treatment., (© 2019 American Academy of Sleep Medicine.)

Objective: An association between migraine and sleep disturbances in children was reported, yet limited clinical data exist. The current study addresses the clinical presentation, polysomnographic (PSG) characteristics, and comorbid sleep diagnoses of children with migraine referred to the sleep clinic., Patients: A retrospective review was performed of headache center patients evaluated by the sleep center between 2007 and 2017. Children ≤18 years old, diagnosed with migraine headache, and who had PSG within one year of evaluation in the headache clinic, were included. PSG findings, as well as demographics, were compared to a group of controls aged 5-14 years-old., Results: In sum, 185 children with a diagnosis of migraine were included: 39% males, 75% Caucasian, mean age 13.5 ± 3.4, and 57% obese. Additionally, 180 children were included in the control group. The common presenting sleep symptoms were snoring (66%), sleep onset and sleep maintenance problems (25%), and excessive daytime sleepiness (20%). For the sleep diagnosis, 40% had obstructive sleep apnea (OSA), 27% had insomnia, 15% had periodic limb movement disorder (PLMD), and 6% had a central disorder of hypersomnolence. In terms of sleep architecture, children with migraine had significantly higher NREM 2 (p < 0.001) and a lower percentage of NREM3 (p < 0.001) compared to controls after adjustment for demographics and the presence of sleep-disordered breathing., Conclusions: Children referred to the sleep clinic who also had migraine, experience various types of sleep complaints. OSA, insomnia, and PLMD were relatively common in this population. Changes in sleep architecture, specifically increased NREM2 and decreased slow wave sleep compared to the control group, were also observed., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Study Objectives: We propose a unique device-independent approach to analyze long-term actigraphy signals that can accurately quantify the severity of periodic limb movements in sleep (PLMS)., Methods: We analyzed 6-8 hr of bilateral ankle actigraphy data for 166 consecutively consenting patients who simultaneously underwent routine clinical polysomnography. Using the proposed algorithm, we extracted 14 time and frequency features to identify PLMS. These features were then used to train a Naïve-Bayes learning tool which permitted classification of mild vs. severe PLMS (i.e. periodic limb movements [PLM] index less than vs. greater than 15 per hr), as well as classification for four PLM severities (i.e. PLM index < 15, between 15 and 29.9, between 30 and 49.9, and ≥50 movements per hour)., Results: Using the proposed signal analysis technique, coupled with a leave-one-out cross-validation method, we obtained a classification accuracy of 89.6%, a sensitivity of 87.9%, and a specificity of 94.1% when classifying a PLM index less than vs. greater than 15 per hr. For the multiclass classification for the four PLM severities, we obtained a classification accuracy of 85.8%, with a sensitivity of 97.6%, and a specificity of 84.8%., Conclusions: Our approach to analyzing long-term actigraphy data provides a method that can be used as a screening tool to detect PLMS using actigraphy devices from various manufacturers and will facilitate detection of PLMS in an ambulatory setting., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Study Objectives: Atopic dermatitis (AD) is a prevalent, chronic, itchy skin condition. Children undergoing polysomnography (PSG) may coincidentally have AD. Many children with AD have sleep disturbances. Our study aimed to characterize limb movements in children with AD and their effect on sleep., Methods: A retrospective chart review was conducted for children who underwent comprehensive attended PSG and had AD. PSG sleep parameters were compared to published normative data. A subset of patients with markedly elevated total limb movements was further compared to a matched group of patients with a diagnosis of periodic limb movement disorder (PLMD) and no history of AD., Results: There were 34 children with AD 6.36 ± 3.21 years (mean ± standard deviation), 50% female and with mild to moderate AD. There was increased wake after sleep onset (WASO = 46.0 ± 37.8 minutes), sleep onset latency (46.5 ± 53.0 minutes) and total limb movement index (13.9 ± 7.5 events/h) compared to normative values. Although our cohort was mostly mild AD, 7 of the 34 children with AD (20%) had a total limb movement index during sleep > 15 events/h. Increased total limb movements in PLMD versus patients with AD was most notable during stage N2 sleep (38 ± 17 versus 22 ± 7, P = .01, respectively)., Conclusions: We found altered PSG parameters in children with AD, suggesting that clinicians should consider the diagnosis when affected children undergo PSG. Although our AD cohort was mild, we still determined a need to consider AD when diagnosing PLMD given the presence of elevated total limb movements in children with AD., Citation: Treister AD, Stefek H, Grimaldi D, Rupani N, Zee P, Yob J, Sheldon S, Fishbein AB. Sleep and limb movement characteristics of children with atopic dermatitis coincidentally undergoing clinical polysomnography. J Clin Sleep Med. 2019;15(8):1107-1113., (© 2019 American Academy of Sleep Medicine.)

Study Objectives: To validate Ullanlinna Narcolepsy Scale (UNS) as a screening tool for narcolepsy in a clinical population and to compare it with Swiss Narcolepsy Scale (SNS) and Epworth Sleepiness Scale (ESS)., Methods: UNS questionnaires of 267 participants visiting Helsinki Sleep Clinic were analyzed. The diagnoses of the participants were narcolepsy type 1 (NT1, n = 89), narcolepsy type 2 (NT2, n = 10), other hypersomnias (n = 24), sleep apnea (n = 37), restless legs syndrome or periodic limb movement disorder (n = 56), and other sleep-related disorders (n = 51). In addition, ESS and SNS scores in a subset of sample (total N = 167) were analyzed and compared to UNS., Results: Mean UNS score in NT1 was 22.0 (95% confidence interval [CI] = 20.4 to 23.6, range 9-43), which was significantly higher than in other disorders, including NT2 (mean 13.7, 95% CI = 10.3 to 17.1, range 7-21, p = .0013). Sensitivity and specificity of UNS in separating NT1 from other disorders were 83.5% and 84.1%, respectively. Positive and negative predictive values were 82.5% and 85.1%, respectively. Sensitivities of SNS and ESS in NT1 were 77.2% and 88.6%, and specificities 88.6% and 45.5%, respectively. There were no differences in receiver operating characteristic curves between UNS and SNS. UNS had moderate negative correlation with hypocretin-1 levels (rs = -.564, p < .001), and mean sleep latency in multiple sleep latency test (rs= -.608, p < .001)., Conclusions: UNS has high specificity and sensitivity for NT1 in a sleep clinic setting. UNS scores below 9 strongly suggest against the diagnosis of narcolepsy., (© Sleep Research Society 2018. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Sleep disorders are frequent and can have serious consequences on patients' health and quality of life. While some sleep disorders are more challenging to treat, most can be easily managed with adequate interventions. We review the main diagnostic features of 6 major sleep disorders (insomnia, circadian rhythm disorders, sleep-disordered breathing, hypersomnia/narcolepsy, parasomnias, and restless legs syndrome/periodic limb movement disorder) to aid medical practitioners in screening and treating sleep disorders as part of clinical practice., (Copyright © 2018. Published by Elsevier Inc.)

Periodic limb movements in sleep (PLMS) are associated with adverse outcomes in patients with heart failure (HF). The aim of this study was to investigate whether PLMS change in response to adaptive servo-ventilation (ASV) for central sleep apnea (CSA) in patients with HF. We examined polysomnographic studies conducted between 2010 and 2014 at Mayo Clinic, Rochester, Minnesota (n = 14,444). In those, 314 of 579 patients with CSA completed the sleep study with a protocol that began with diagnostic polysomnography, followed by continuous positive airway pressure, and, for persistent CSA, by ASV titration. Patients with HF (n = 118) had a significantly higher median PLM index compared with those without HF (n = 196): 33.7 versus 6.1 events/h (p <0.001). HF was associated with a significant PLM arousal index (PLMAI) increase from diagnostic trial to ASV (odds ratio [OR]  = 1.79, p = 0.032) after adjusting for demographics, co-morbidities and medications. In patients aged >68 years, HF was associated with PLMI and PLMAI increases during ASV (OR  = 2.16, p = 0.016 and OR  = 2.05, p = 0.024), which persisted in multivariable models (OR  = 2.36, p = 0.025 and OR  = 2.33, p = 0.026). In multivariable analysis, patients with ejection fraction ≤45% had higher odds of increased PLMAI during ASV than those with ejection fraction >45% (OR  = 1.98, p = 0.022). In conclusion, PLMS may increase in HF patients after suppression of CSA by ASV. Whereas the clinical significance of increased post-ASV PLMS in HF prognosis needs to be determined, these increases may contribute to worsening outcomes in HF patients with CSA treated with ASV., (Copyright © 2018. Published by Elsevier Inc.)

Background: Documentation of REM sleep without atonia is fundamental for REM sleep behavior disorder (RBD) diagnosis. The automated REM atonia index (RAI), Frandsen index (FRI) and Kempfner index (KEI) were proposed for this, but achieved moderate performances., New Method: Using sleep data from 27 healthy controls (C), 29 RBD patients and 36 patients with periodic limb movement disorder (PLMD), we developed and validated a new automated data-driven method for identifying movements in chin and tibialis electromyographic (EMG) signals. A probabilistic model of atonia from REM sleep of controls was defined and movements identified as EMG areas having low likelihood of being atonia. The percentages of movements and the median inter-movement distance during REM and non-REM (NREM) sleep were used for distinguishing C, RBD and PLMD by combining three optimized classifiers in a 5-fold cross-validation scheme., Results: The proposed method achieved average overall validation accuracies of 70.8% and 61.9% when REM and NREM, and only REM features were used, respectively. After removing apnea and arousal-related movements, they were 64.2% and 59.8%, respectively., Comparison With Existing Method(s): The proposed method outperformed RAI, FRI and KEI in identifying RBD patients and in particular achieved higher accuracy and specificity for classifying RBD., Conclusions: The results show that i) the proposed method has higher performances than the previous ones in distinguishing C, RBD and PLMD patients, ii) removal of apnea and arousal-related movements is not required, and iii) RBD patients can be better identified when both REM and NREM muscular activities are considered., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Purpose: This study investigated the basal autonomic regulation in patients with obstructive sleep apnea (OSA) showing periodic limb movements in sleep (PLMS) emerging after therapy with continuous positive airway pressure (CPAP)., Methods: Data of patients with OSA undergoing a first polysomnography for diagnosis and a second polysomnography for therapy with CPAP were reviewed. Patients with OSA showing PLMS on the first polysomnography were excluded. By using heart rate variability analysis, epochs without any sleep events and continuous effects from the second polysomnography were retrospectively analyzed., Results: Of 125 eligible patients, 30 with PLMS after therapy with CPAP (PLMS group) and 30 not showing PLMS on both polysomnography (non-PLMS group) were randomly selected for the analysis. No significant differences in the demographic characteristics and variables of polysomnographies were identified between the groups. Although one trend of low root mean square of successive differences (RMSSD) between intervals of adjacent normal heart beats (NN intervals) in the PLMS group was observed, patients in the PLMS group had significantly low normalized high-frequency (n-HF) and high-frequency (HF) values, but high normalized low frequency (n-LF) and high ratio of LF to HF (LF/HF ratio). After adjustment for confounding variables, PLMS on the second polysomnography was significantly associated with RMSSD (β = - 6.7587, p = 0.0338), n-LF (β = 0.0907, p = 0.0148), n-HF (β = - 0.0895, p = 0.0163), log LF/HF ratio (β = 0.4923, p = 0.0090), and log HF (β = - 0.6134, p = 0.0199)., Conclusions: Patients with OSA showing PLMS emerging after therapy with CPAP may have a basal sympathetic predominance with potential negative cardiovascular effects.

Background: There is growing evidence of increased cardiovascular risk including hypertension in patients with periodic limb movements during sleep (PLMS). In a multiethnic cohort study, the association between prevalent hypertension and PLMS varied according to ethnicity. We evaluated whether PLMS are associated with hypertension in Koreans., Methods: We enrolled 1,163 subjects who had polysomnography (PSG) from 2 tertiary hospitals. All subjects completed a sleep questionnaire before the PSG study. Coincidental hypertension was recorded according to past medical history. We analyzed the association between periodic limb movement index (PLMI), periodic limb movement associated with arousal index (PLMAI), and coincidental hypertension. Covariates were age, sex, body mass index (BMI), restless legs syndrome, apnea-hypopnea index (AHI), arousal index, and average oxygen saturation., Results: A total of 304 subjects (26.1%) had hypertension. The proportion of subjects with hypertension in the PLMI ≥ 15 category was higher than that in the PLMI < 15 category (32.4% vs. 25.0%; P = 0.04). The proportion of subjects with hypertension in the PLMAI ≥ 1 category was 32.6%, which was higher than that in the PLMAI < 1 category (24.6%; P = 0.02). In a multivariate regression model, neither PLMI (odds ratio [OR], 1.12; 95% confidence interval [CI] 0.75-1.68) nor PLMAI (OR, 1.21; 95% CI 0.83-1.76) were associated with hypertension. Statistical significance was found between coincidental hypertension and the following variables: age, smoking history, BMI, and AHI., Conclusions: In a retrospective hospital-based study, there was no association between coincidental hypertension and PLMI/PLMAI in Koreans.

Dopamine agonists such as pramipexole are commonly used in the treatment of restless legs syndrome (RLS) as well as Parkinson's disease. Pramipexole's common side effects are well documented; however, adverse skin reactions are less well known. In this case, a 45-year-old male farmer presented with excessive daytime tiredness and reported a history suggestive of RLS. He was initiated on pramipexole but developed a maculopapular erythematous rash in sun-exposed areas 8 days after its commencement. The skin rash resolved following pramipexole's cessation and it is thought the patient experienced a drug-induced photosensitivity reaction to pramipexole. This case highlights the potential for photosensitivity reactions to pramipexole, which is especially significant in countries like Australia where UV solar radiation is especially high., (© Royal College of Physicians 2018. All rights reserved.)

Study Objectives: To define statistically the upper limit of the intermovement interval (IMI, the time interval between the onset of consecutive movements) of periodic leg movements during sleep (PLMS)., Methods: We computed the IMI distribution of a large sample (n = 141) of patients with restless legs syndrome (RLS) and analyzed it with two independent approaches, based on fitting either empirical functions or normal and exponential functions to the data., Results: The two fitting approaches consistently pointed to an upper limit of the PLMS IMI in the range between 50 and 60 s. Decreasing the upper limit of PLMS IMI from 90 to 60 s evidently decreased the PLMS index in patients with RLS and control participants; nevertheless, the PLMS index remained significantly higher in RLS vs. control participants. Shifting the upper limit of PLMS IMI to 60 s did not significantly modify the effectiveness of discrimination of PLMS between controls and patients with RLS., Conclusion: These results seem to indicate that a conservative, yet data-driven upper limit for IMI contributing to the PLMS in patients with RLS might be 60 s instead of 90 s, as recommended by the present guidelines.

Purpose: Recent studies found that the non-contact screening device SleepMinder (ResMed Sensor Technologies, Dublin, Ireland) detects sleep-disordered breathing (SDB) with high diagnostic accuracy in cohorts suspected of this disorder. However, it was reported that in patients with periodic limb movement in sleep (PLMS), this non-contact device overestimates the apnea-hypopnea index (AHI). We aimed to overcome this limitation by introducing the novel sleep disorder index (SDI) which is sum of the AHI and the period limb movement index (PLMI)., Methods: Between January 2011 and December 2013, we studied a mixed cohort of 57 patients (31 OSA, 19 PLMS). The easy-to-use non-contact device emits a very weak electromagnetic radiation and detects body movement by measuring the Doppler effect. We interpreted the device-generated movement index as the SDI and validated the diagnostic accuracy against simultaneous application of the gold-standard polysomnography (PSG)., Results: We found that the SDI of the non-contact device correlated well with the sum of AHI and PLMI derived from PSG (r = 0.79, p = 0.01). For PSG-derived SDI cutoff ≥ 15/h, we obtained a sensitivity of 92.2% and a specificity of 95.8%. Positive likelihood ratio was 23.3 and negative likelihood ratio 0.03., Conclusions: The studied non-contact screening device detects accurately the combination of the sleep disorders SDB and/or PLM. However, further testing is required in order to specify the nature of the underlying sleep disorder. At the current stage of algorithm development, the clinical strength is that the studied non-contact device can be used as a rule-out screening device for SDB and PLM.

Background and Purpose: Periodic limb movements of sleep (PLMS) are usually comorbid with hypertension, tachycardia, and coronary arterial diseases, which are also risk factors for cerebrovascular accidents (CVA). However, evidence about the relationship between CVA and PLMS is still weak. The aim of this study was to investigate (1) the prevalence of CVA in patients with PLMS, and (2) the severity of PLMS in patients with or without CVA through a meta-analysis., Methods: The electronic databases of PubMed, Embase, ScienceDirect, ClinicalKey, Cochrane Library, ProQuest, Web of Science, and ClinicalTrials.gov were searched. The inclusion criteria were (1) articles investigating comorbidity between PLMS and CVA, and (2) clinical trials in humans., Results: This meta-analysis included (1) 9,823 patients with PLMS and 9,416 controls from 5 studies to analyze the prevalence of CVA in PLMS, and (2) 158 patients with PLMS with CVA and 88 PLMS controls without CVA from 3 studies to analyze the severity of PLMS with and without CVA. The results showed (1) significantly higher comorbidity rates of CVA in the patients with PLMS than in the controls without PLMS (OR 1.267, p = 0.019), and (2) higher PLM index in the patients with CVA than in the controls (Hedges' g = 0.860, p = 0.001; means difference: 4.435, p = 0.016)., Conclusions: The results revealed (1) a worse severity of PLMS in the patients with CVA, and (2) increased prevalence of CVA in the patients with PLMS. Based on our results, the patients had a higher prevalence of CVA within 8 years of a diagnosis of PLMS compared to those without PLMS by about 1.3-fold. Whether (1) patients with PLMS receiving treatment have a similar incidence of stroke to those without PLMS, and (2) secondary stroke prevention can lower the severity of PLMS or whether those with severe PLMS have a higher risk of stroke is still inconclusive. Future studies investigating the prevalence of CVA in patients with PLMS should use a follow-up period of over 8 years., (© 2018 S. Karger AG, Basel.)

Background: Growing evidence indicates that periodic limb movements of sleep (PLMS) may be related to increased risk of developing cardiovascular disease. However, the association of PLMS with atrial fibrillation (AF) is unclear, especially in patients with sleep-disordered breathing (SDB). This study sought to investigate whether PLMS were associated with increased AF prevalence, independent of established risk factors., Methods: We performed a cross-sectional study of patients who underwent attended polysomnography at Mayo Clinic from 2011 to 2014. The association of PLMS with AF prevalence was estimated by using logistic regression models., Results: 15,414 patients were studied, 76.3% of individuals with SDB defined by apnea-hypopnea index (AHI) ≥5/h, and 15.3% with a diagnosis of AF. In univariate logistic modelling, individuals with periodic limb movement index (PLMI) ≥30/h had higher odds of AF (odds ratio [OR] 1.96, 95% confidence interval [CI]1.79-2.16, p<0.001) when compared to patients with PLMI <15/h. After multivariate adjustment (for age, race, sex, history of smoking, hypertension, diabetes, coronary artery disease, heart failure, cerebrovascular disease, renal disease, iron deficiency anemia, chronic obstructive pulmonary disease, AHI, arousal index), in mild SDB patients, a PLMI ≥30/h or periodic limb movement arousal index (PLMAI) ≥5/h had significantly higher odds of AF than those with PLMI <15/h (OR 1.21, 95% CI 1.00-1.47, p=0.048) or PLMAI <1/h (OR 1.27, 95% CI 1.03-1.56, p=0.024)., Conclusions: Frequent PLMS are independently associated with AF prevalence in patients with mild SDB. Further studies are needed to better understand the relationship with incident AF., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Purpose of Review: This article provides an update on six sleep-related movement disorders: restless legs syndrome (RLS), periodic limb movement disorder, sleep-related leg cramps, bruxism, rhythmic movement disorder, and propriospinal myoclonus, with an emphasis on RLS., Recent Findings: RLS is a common sensorimotor disorder that impairs quality of life. RLS is frequently comorbid to neurologic, psychiatric, vascular, and inflammatory diseases. Accumulating evidence implicates the pathophysiology of RLS as a state of dopamine dysfunction and iron deficiency that occurs on a background of genetic susceptibility conferred by 6 gene polymorphisms. Multiple treatments approved by the US Food and Drug Administration (FDA) are available. Dopamine agonists and α2δ calcium channel ligands are considered first-line treatments, but these treatments have very different side effect profiles that should be taken into consideration., Summary: Sleep-related movement disorders are frequently encountered in clinical practice. For some disorders, particularly RLS and periodic limb movement disorder, our understanding of biology, epidemiology, and treatment is advanced. For others, much work is needed to determine optimal treatment strategies.

Purpose: Periodic limb movements in sleep (PLMS) are related to arousal, sympathetic activation, and increases in blood pressure (BP), but whether they are part of the arousal process or causative of it is unclear. Our objective was to assess the temporal distribution of arousal-related measures around PLMS., Methods: Polysomnographic recordings of six patients with restless legs syndrome were analyzed. We analyzed 15 PLMS, plus three 5-s epochs before and after each movement, for every patient. Mean values per epoch of blood pressure (BP), heart rate (HR), and electroencephalographic (EEG) power were calculated. For each patient, six 5-s epochs of undisturbed sleep were analyzed as controls., Results: Alpha + beta EEG power, systolic BP, and HR were significantly increased following PLMS. The EEG power and HR increases were noticed in the first epoch after PLMS, whereas that of systolic BP was observed in the second and third epochs following a PLMS. No significant changes occurred in the epochs of undisturbed sleep., Conclusions: The results suggest that PLMS are followed by arousal-related nervous system events. Given the high frequency of PLMS throughout the night, they could be a potential risk factor for nocturnal arrhythmias and hypertension, in addition to causing sleep deprivation.

Restless legs syndrome is a frequent neurological disorder with potentially serious and highly distressing treatment complications. The role and potential implications of periodic leg movements during sleep range from being a genetic risk marker for restless legs syndrome to being a cardiovascular risk factor. The diagnosis of restless legs syndrome in patients with daytime movement disorders is challenging and restless legs syndrome needs to be differentiated from other sleep-related movement disorders. This article provides an update on the diagnosis of restless legs syndrome as an independent disorder and the role of periodic leg movements and reviews the association of restless legs syndrome with Parkinson's disease and other movement disorders. © 2017 International Parkinson and Movement Disorder Society., (© 2017 International Parkinson and Movement Disorder Society.)

Objectives: Apelin is an antioxidant and anti-inflammatory molecule secreted by adipose tissue and has a protective effect on cardiac and neuronal tissue. Recent studies have reported that the risk of vascular disease is increased in restless legs syndrome (RLS). We aimed to measure plasma levels of apelin in patients with RLS. Additionally, we wanted to determine if there is any relationship between apelin levels and RLS disease severity and the periodic leg movement index (PLMI)., Method: A total of 14 RLS patients with moderate-to-severe symptoms and 14 age- and body mass index (BMI)-matched healthy controls participated in the study. All participants had no concomitant medical disorder nor took medications. The international RLS rating scale (IRLSS) was used to determine disease severity. Polysomnography (PSG) served to exclude other sleep disorders such as sleep-related breathing disorders and to measure sleep parameters., Results: The mean plasma apelin level was significantly lower in the patient group compared to the control group independent of IRLSS score and PSG findings (p = 0.004). After comparison between the RLS patient group and control group, the patient group was divided into two subgroups based on a PLMI above or below 15 events per hour. A reduced mean apelin level was observed in the patient group having a PLMI above 15 compared to the patient group with PLMI below 15 and the control group (p = 0.003). There was no correlation between plasma apelin levels and disease severity and PLMI in the two patient subgroups., Conclusions: RLS patients especially those with a PLMI above 15 have low plasma apelin levels independent of disease severity and sleep parameters such as sleep duration and quality. Decreased apelin levels may explain the increased risk for vascular diseases in those patients.

Study Objectives: To describe a group of patients referred because of abnormal sleep behaviors that were suggestive of rapid eye movement (REM) sleep behavior disorder (RBD) in whom video-polysomnography ruled out RBD and showed the reported behaviors associated with vigorous periodic limb movements during sleep (PLMS)., Aims and Methods: Clinical history and video-polysomnography review of patients identified during routine visits in a sleep center., Results: Patients were 15 men and 2 women with a median age of 66 (range: 48-77) years. Reported sleep behaviors were kicking (n = 17), punching (n = 16), gesticulating (n = 8), falling out of bed (n = 5), assaulting the bed partner (n = 2), talking (n = 15), and shouting (n = 10). Behaviors resulted in injuries in 3 bed partners and 1 patient. Twelve (70.6%) patients were not aware of displaying abnormal sleep behaviors that were only noticed by their bed partners. Ten (58.8%) patients recalled unpleasant dreams such as being attacked or chased. Video-polysomnography showed (1) frequent and vigorous stereotyped PLMS involving the lower limbs, upper limbs, and trunk (median PLMS index 61.2; median PLMS index in NREM sleep 61.9; during REM sleep only 8 patients had PLMS and their median PLMS index in REM sleep was 39.5); (2) abnormal behaviors (e.g., punching, groaning) during some of the arousals that immediately followed PLMS in NREM sleep; and (3) ruled out RBD and other sleep disorders such as obstructive sleep apnea. Dopaminergic agents were prescribed in 14 out of the 17 patients and resulted in improvement of abnormal sleep behaviors and unpleasant dreams in all of them. After dopaminergic treatment, follow-up video-polysomnography in 7 patients showed a decrease in the median PLMS index from baseline (108.9 vs. 19.2, p = .002) and absence of abnormal behaviors during the arousals., Conclusions: Abnormal sleep behaviors and unpleasant dreams simulating RBD symptomatology may occur in patients with severe PLMS. In these cases, video-polysomnography ruled out RBD and identified prominent PLMS followed by arousals containing abnormal behaviors. Our cases represent an objectively documented subtype of periodic limb movement disorder causing abnormal sleep behaviors., (© Sleep Research Society 2016. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)