Impaired sleep is associated with tau deposition on 18F-flortaucipir PET and accelerated cognitive decline, accounting for medications that affect sleep.

BACKGROUND: Impaired sleep is commonly associated with Alzheimer's disease (AD), although the underlying mechanisms remain unclear. Furthermore, the moderating effects of sleep-affecting medications, which have been linked to AD pathology, are incompletely characterized. Using data from the Alzheimer's Disease Neuroimaging Initiative, we investigated whether a medical history of impaired sleep, informant-reported nighttime behaviors, and sleep-affecting medications are associated with beta-amyloid and tau deposition on PET and cognitive change, cross-sectionally and longitudinally. METHODS: We included 964 subjects with 18F-florbetapir PET scans. Measures of sleep impairment and medication use were obtained from medical histories and the Neuropsychiatric Inventory Questionnaire. Multivariate models, adjusted for covariates, were used to assess associations among sleep-related features, beta-amyloid and tau, and cognition. Cortical tau deposition, categorized by Braak stage, was assessed using the standardized uptake value peak alignment (SUVP) method on 18F-flortaucipir PET. RESULTS: Medical history of sleep impairment was associated with greater baseline tau in the meta-temporal, Braak 1, and Braak 4 regions (p = 0.04, p < 0.001, p = 0.025, respectively). Abnormal nighttime behaviors were also associated with greater baseline tau in the meta-temporal region (p = 0.024), and greater cognitive impairment, cross-sectionally (p = 0.007) and longitudinally (p < 0.001). Impaired sleep was not associated with baseline beta-amyloid (p > 0.05). Short-term use of selective serotonin reuptake inhibitors and benzodiazepines slightly weakened the sleep-tau relationship. CONCLUSIONS: Sleep impairment was associated with tauopathy and cognitive decline, which could be linked to increased tau secretion from neuronal hyperactivity. Clinically, our results help identify high-risk individuals who could benefit from sleep-related interventions aimed to delay cognitive decline and AD.

Detection and Prediction of Sleep Disorders by Covert Bed-Integrated RF Sensors.

OBJECTIVE: Respiratory disturbances during sleep are a prevalent health condition that affects a large adult population. The gold standard to evaluate sleep disorders including apnea is overnight polysomnography, which requires a trained technician for live monitoring and post-processing scoring. Currently, the disorder events can hardly be predicted using the respiratory waveforms preceding the events. The objective of this paper is to develop an autonomous system to detect and predict respiratory events reliably based on real-time covert sensing. METHODS: A bed-integrated radio-frequency (RF) sensor by near-field coherent sensing (NCS) was employed to retrieve continuous respiratory waveforms without user's awareness. Overnight recordings were collected from 27 patients in the Weill Cornell Center for Sleep Medicine. We extracted respiratory features to feed into the random-forest machine learning model for disorder detection and prediction. The technician annotation, derived from observation by polysomnography, was used as the ground truth during the supervised learning. RESULTS: Apneic event detection achieved a sensitivity and specificity up to 88.6% and 89.0% for k-fold validation, and 83.1% and 91.6% for subject-independent validation. Prediction of forthcoming apneic events could be made up to 90 s in advance. Apneic event prediction achieved a sensitivity and specificity up to 81.3% and 82.1% for k-fold validation, and 80.5% and 82.4% for subject-independent validation. The most important features for event detection and prediction can be assessed in the learning model. CONCLUSION: A bed-integrated RF sensor can covertly and reliably detect and predict apneic events. SIGNIFICANCE: Predictive warning of the sleep disorders in advance can intervene serious apnea, especially for infants, servicemen, and patients with chronic conditions.

Neurologic and psychiatric features of impending neurodegeneration in iRBD.

Introduction: Idiopathic rapid eye movement (REM) sleep behavior disorder (iRBD) is linked to Parkinson's disease and other alpha-synucleinopathies, but various subsets of iRBD may not carry equal risk (i.e., those with depression are at higher risk than those without). Here, we prospectively focus on neurologic and psychiatric aspects of subjects with iRBD, in an attempt to determine what factors are prominent in those who undergo phenoconversion as opposed to those who do not. Methods: We analyzed data from the "REM Sleep Behavior Disorder Associations with Parkinson's Disease Study (RAPiDS)" cohort both at baseline and then at follow-up evaluations (1 to 3 years later) utilizing several neurologic batteries, including the Movement Disorder Society's Unified Parkinson's Disease Rating Scale (MDS-UPDRS), the Montreal Cognitive Assessment (MoCA), the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP), the 10-M Walk Test (10MWT), and the Epworth Sleepiness Scale. Determination of phenoconversion was ascertained from physical examination and medical chart review from the initial evaluation onward. Results: Of those who completed both evaluations, there were 33 subjects with iRBD, with an average age of 63.1 ± 12.8 years, with 9 women and 24 men. Of these, 8 (24%) iRBD subjects developed neurodegenerative illness, and demonstrated multiple areas of neurologic and psychiatric signs and symptoms, such as speech and movement problems as well as anxiety and depression. Conclusions: Our data adds to the literature regarding risk of phenoconversion in those with iRBD. Further study will be needed, but it is clear that not all subjects with iRBD present the same risk for neurodegeneration.

Deduced Respiratory Scores on COVID-19 Patients Learning from Exertion-Induced Dyspnea.

Dyspnea is one of the most common symptoms of many respiratory diseases, including COVID-19. Clinical assessment of dyspnea relies mainly on self-reporting, which contains subjective biases and is problematic for frequent inquiries. This study aims to determine if a respiratory score in COVID-19 patients can be assessed using a wearable sensor and if this score can be deduced from a learning model based on physiologically induced dyspnea in healthy subjects. Noninvasive wearable respiratory sensors were employed to retrieve continuous respiratory characteristics with user comfort and convenience. Overnight respiratory waveforms were collected on 12 COVID-19 patients, and a benchmark on 13 healthy subjects with exertion-induced dyspnea was also performed for blind comparison. The learning model was built from the self-reported respiratory features of 32 healthy subjects under exertion and airway blockage. A high similarity between respiratory features in COVID-19 patients and physiologically induced dyspnea in healthy subjects was observed. Learning from our previous dyspnea model of healthy subjects, we deduced that COVID-19 patients have consistently highly correlated respiratory scores in comparison with normal breathing of healthy subjects. We also performed a continuous assessment of the patient's respiratory scores for 12-16 h. This study offers a useful system for the symptomatic evaluation of patients with active or chronic respiratory disorders, especially the patient population that refuses to cooperate or cannot communicate due to deterioration or loss of cognitive functions. The proposed system can help identify dyspneic exacerbation, leading to early intervention and possible outcome improvement. Our approach can be potentially applied to other pulmonary disorders, such as asthma, emphysema, and other types of pneumonia.

Risk of post-acute sequelae of SARS-CoV-2 infection associated with pre-coronavirus disease obstructive sleep apnea diagnoses: an electronic health record-based analysis from the RECOVER initiative.

STUDY OBJECTIVES: Obstructive sleep apnea (OSA) has been associated with more severe acute coronavirus disease-2019 (COVID-19) outcomes. We assessed OSA as a potential risk factor for Post-Acute Sequelae of SARS-CoV-2 (PASC). METHODS: We assessed the impact of preexisting OSA on the risk for probable PASC in adults and children using electronic health record data from multiple research networks. Three research networks within the REsearching COVID to Enhance Recovery initiative (PCORnet Adult, PCORnet Pediatric, and the National COVID Cohort Collaborative [N3C]) employed a harmonized analytic approach to examine the risk of probable PASC in COVID-19-positive patients with and without a diagnosis of OSA prior to pandemic onset. Unadjusted odds ratios (ORs) were calculated as well as ORs adjusted for age group, sex, race/ethnicity, hospitalization status, obesity, and preexisting comorbidities. RESULTS: Across networks, the unadjusted OR for probable PASC associated with a preexisting OSA diagnosis in adults and children ranged from 1.41 to 3.93. Adjusted analyses found an attenuated association that remained significant among adults only. Multiple sensitivity analyses with expanded inclusion criteria and covariates yielded results consistent with the primary analysis. CONCLUSIONS: Adults with preexisting OSA were found to have significantly elevated odds of probable PASC. This finding was consistent across data sources, approaches for identifying COVID-19-positive patients, and definitions of PASC. Patients with OSA may be at elevated risk for PASC after SARS-CoV-2 infection and should be monitored for post-acute sequelae.

Development and palliative care staff reactions to a sleep regulation educational intervention.

BACKGROUND: In palliative care, sleep and circadian rhythm problems are common symptoms. Nonpharmacological interventions are available; however, health care providers are not aware of these or lack the knowledge to effectively implement in practice. This study reports the content and design development of the PRIME™ (Program for Improving & Managing Environments for Sleep) sleep online educational intervention as well as the evaluation of the intervention by practicing nurses with a focus on perceived acceptability and satisfaction. METHODS: Development of the education employed a multi-step process that assesses the current state of the science in this area (literature reviews), the needs of regional target recipients (hospice/palliative care staff), expert recommendations and views of a national pool of hospice/palliative workers. A cross-sectional, descriptive study with key staff informants evaluated the acceptability and usability of the modules using both scale-response items to rate the content and design of the modules and overall satisfaction and five open-response questions to suggest changes to the educational intervention. RESULTS: Among 31 palliative care professionals, most rated the content and design favorably. A total of 20 participants provided suggestions to improve the educational intervention. Their comments were categorized into six themes: Integration into Practice; Content, Exercises and Material Provided by Modules; User Interface and Design; and Adapt and Expand Modules for Public, Family and Caregivers. CONCLUSIONS: The data suggest that the PRIME™ educational intervention can be an effective tool to train direct-care palliative care professionals on interventions for use in their daily practice. We also demonstrated that the educational intervention is feasible to deliver online and that the online modules appealed to respondents, suggesting that future delivery of the educational intervention can use the same or similar modes of presentation.

Systematic review: auditory stimulation and sleep.

STUDY OBJECTIVES: Auditory stimulation devices (white and pink noise) are used to mask sounds and facilitate relaxation and sleep; however, the effectiveness of this intervention is not well established. This systematic review examined the scientific literature for the effect of specific types of auditory stimulation on sleep outcomes in adults. METHODS: The PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) statement guided this review. Searches were conducted in 9 databases for intervention studies that could easily be employed in clinical practice. We excluded other types of auditory stimulation (music alone, binaural tones, and synchronization). Two reviewers screened abstracts and full-text articles for eligibility, with conflicts resolved by a third reviewer, and extracted data. Risk of bias was assessed with the Effective Public Health Practice Project Quality Assessment Tool for Quantitative Studies. RESULTS: Thirty-four studies reported results of 1,103 persons participating in 3 categories of interventions: white noise (18), pink noise (11), and 6 multiaudio (some combination of white, pink, music, or silence). Nineteen studies had positive findings in terms of improving sleep outcomes: 6 white noise (33%), 9 pink noise (81.9%), and 4 multiaudio (66.7%). Multiaudio had the lowest (better) risk of bias (mean/standard deviation: 1.67/0.82) compared to white (2.38/0.69) and pink noise (2.36/0.81). CONCLUSIONS: Although there was no strong evidence to support use of auditory stimulation, none of the studies reported any adverse effects with short-term application of auditory stimulation during sleep. Future research needs to include confounding factors that can affect outcomes, including one's noise sensitivity, personality, and other conditions or medications that may affect sleep. CITATION: Capezuti E, Pain K, Alamag E, Chen XQ, Philibert V, Krieger AC. Systematic review: auditory stimulation and sleep. J Clin Sleep Med. 2022;18(6):1697-1709.

Obstructive Sleep Apnea: Non-positive Airway Pressure Treatments.

Undiagnosed and untreated obstructive sleep apnea (OSA) is associated with health comorbidities and negatively affects quality of life. Alternative treatments should be considered in patients who are unable to tolerate or benefit from positive airway pressure treatment. When properly indicated, positional devices, oral appliances, airway surgery, and hypoglossal nerve stimulation have been shown to be effective in treating OSA. Hypoglossal nerve stimulation is a successful second-line treatment with low associated morbidity and complication rate.

The effects of white noise on sleep and duration in individuals living in a high noise environment in New York City.

INTRODUCTION: Undisturbed sleep has been shown to be important for both health and quality of life (Medic et al. [7]). The World Health Organization estimates that nearly 25% of the population suffers from disturbed sleep due to environmental noise (Health TWECfEa, [2]). Sleep disturbance associated with elevated noise levels is particularly prevalent in metropolitan areas. Our study tested the hypothesis that white noise would improve sleep in New Yorkers complaining of sleep difficulty due to elevated sound levels. METHODS: Ten adult participants were included in this study. All participants were recruited from a New York City based sleep clinic. Inclusion criteria was based on the presence of sleep disturbance and the reporting of high levels of environmental noise in participants' sleep location. The study was conducted using a within-subject, ABA design, with baseline, treatment phase, followed by another baseline (washout) period. Each phase lasted one-week, during which noise level and sleep were assessed. The treatment consisted of the application of a white noise device (Dohm Classic by Marpac, LLC) in the participants' bedroom. Sleep parameters were measured subjectively using the Consensus Sleep Diary (Carney et al. [15]), and objectively using a Motionlogger Actigraph. RESULTS: Paired sample t-tests were conducted to evaluate the hypothesis that white noise improves sleep in a high noise environment. Significance was found on the variables WASO, as measured by actigraphy, t(9) = 3.438, p = 0.007 and sleep latency as measured by sleep diary, t(9) = 2.947, p = 0.016. There was a trend toward significance on the number of awakenings during the night, as measured by sleep diary, t(9) = 2.622, p = 0.028 (Holm's sequential correction of p-value required a value of <0.01 to find significance on this comparison) and sleep efficiency (actigraph), t(9) = -2.121, p = 0.063. CONCLUSION: Our data show that white noise significantly improved sleep based on subjective and objective measurements in subjects complaining of difficulty sleeping due to high levels of environmental noise. This suggests that the application of white noise may be an effective tool in helping to improve sleep in those settings.

The Importance of Mask Selection on Continuous Positive Airway Pressure Outcomes for Obstructive Sleep Apnea. An Official American Thoracic Society Workshop Report.

Continuous positive airway pressure (CPAP) remains the major treatment option for obstructive sleep apnea (OSA). The American Thoracic Society organized a workshop to discuss the importance of mask selection for OSA treatment with CPAP. In this workshop report, we summarize available evidence about the breathing route during nasal and oronasal CPAP and the importance of nasal symptoms for CPAP outcomes. We explore the mechanisms of air leaks during CPAP treatment and possible alternatives for leak control. The impact of nasal and oronasal CPAP on adherence, residual apnea-hypopnea index, unintentional leaks, and pressure requirements are also compared. Finally, recommendations for patient and partner involvement in mask selection are presented, and future directions to promote personalized mask selection are discussed.

Increased platelet activation in sleep apnea subjects with intermittent hypoxemia.

PURPOSE: Obstructive sleep apnea (OSA) is independently associated with increased risk for stroke and other cardiovascular diseases. Since activated platelets play an important role in cardiovascular disease, the objective of this study was to determine whether platelet reactivity was altered in OSA subjects with intermittent nocturnal hypoxemia. METHODS: Thirty-one subjects, without hypertension or cardiovascular disease and not taking medication, participated in the study. Subjects were stratified based on OSA-related oxygen desaturation index (ODI) recorded during overnight polysomnography. Platelet reactivity to a broad panel of agonists (collagen, thrombin, protease-activated receptor1 hexapeptide, epinephrine, ADP) was measured by monitoring platelet aggregation and ATP secretion. Expression of platelet activation markers CD154 (CD40L) and CD62P (P-selectin) and platelet-monocyte aggregates (PMA) was quantified by flow cytometry. RESULTS: Epinephrine-induced platelet aggregation was substantially decreased in OSA subjects with significant intermittent hypoxemia (ODI ≥ 15) compared with subjects with milder hypoxemia levels (ODI < 15) (area under curve, p = 0.01). In addition, OSA subjects with ODI ≥ 15 exhibited decreased thrombin-induced platelet aggregation (p = 0.02) and CD40L platelet surface expression (p = 0.05). Platelet responses to the other agonists, CD62P platelet surface expression, and PMA levels were not significantly different between groups. Reduction in platelet responses to epinephrine and thrombin, and decreased CD40L surface marker expression in significant hypoxemic OSA individuals, is consistent with their platelets being in an activated state. CONCLUSIONS: Increased platelet activation was present in otherwise healthy subjects with intermittent nocturnal hypoxemia due to underlying OSA. This prothrombotic milieu in the vasculature is likely a key contributing factor toward development of thrombosis and cardiovascular disease. TRIAL REGISTRATION: NCT00859950.

Comorbid neuropsychiatric and autonomic features in REM sleep behavior disorder.

OBJECTIVE: Our aim is to define the extent of comorbidities in order to improve clinical care of patients with idiopathic rapid eye movement sleep behavior disorder (iRBD) utilizing the REM Sleep Behavior Disorder Associations with Parkinson's Disease Study (RAPiDS) cohort. METHODS: Consecutive adult study participants with iRBD confirmed on polysomnogram (PSG) were prospectively recruited from the Weill Cornell Center for Sleep Medicine. Evaluations comprised multiple facets of sleep, neurological, autonomic, and psychiatric function. RESULTS: Participants evaluated included 30 individuals with iRBD, with mean 1.5 ±â€¯2.3 years from PSG to neuropsychiatric evaluation. Mean age was 59.5 ±â€¯16.0 years at time of PSG, and 6/30 were women. Urinary difficulties were reported in 14/30 (47%): slight 7 (23%), mild 4 (13%), moderate 2 (7%), and severe 1 (3.0%). Ten out of 29 (34%) had abnormal Montreal Cognitive Assessment (MoCA) scores and the mean was 26.5 ±â€¯3.2. The distribution of MoCA scores was significantly associated with urinary problems insofar as the more severe urinary problems were, the lower the MoCA scores (p = 0.04). CONCLUSIONS: In this RAPiDS cohort, we detected an unexpectedly high occurrence of non-motor dysfunction. Our results point to the need for screening patients with iRBD for complaints that are actionable, for example those affecting mood, cognition, urinary function, and bowel function. We propose the term RBD+ to be used to identify such individuals. For the quality of life in patients diagnosed with RBD, a closer look by the clinician should be enacted, with appropriate referrals and workup.

Non-pharmacological solutions to sleep and circadian rhythm disruption: voiced bedside experiences of hospice and end-of-life staff caregivers.

BACKGROUND: Sleep disturbance is a significant issue, particularly for patients with advanced terminal illness. Currently, there are no practice-based recommended approaches for managing sleep and circadian disruptions in this population. To address this gap, a cross-sectional focus group study was performed engaging 32 staff members at four hospices/end-of-life programs in three demographically diverse counties in New York State. METHODS: Participants responded to structured open-ended questions. Responses were transcribed and subjected to qualitative content analysis. The themes and recommendations for improved practice that emerged were tabulated using Atlas TI qualitative software. RESULTS: This report details the experiences of hospice and end-of-life care staff in managing sleep and circadian disruptions affecting patients and analyzes their recommendations for improving care. Caregivers involved in the study described potential interventions that would improve sleep and reduce circadian disruptions. They particularly highlighted a need for improved evaluation and monitoring systems, as well as sleep education programs for both formal and informal caregivers. CONCLUSIONS: The voiced experiences of frontline hospice and end-of-life caregivers confirmed that disruption in sleep and circadian rhythms is a common issue for their patients and is not effectively addressed in current research and practice. The caregivers' recommendations focused on management strategies and underscored the need for well-tested interventions to promote sleep in patients receiving end-of-life care. Additional research is needed to examine the effectiveness of systematic programs that can be easily integrated into the end-of-life care process to attenuate sleep disturbances.

A systematic review of non-pharmacological interventions to improve nighttime sleep among residents of long-term care settings.

BACKGROUND: Disturbances in sleep and circadian rhythms are common among residents of long-term care facilities. In this systematic review, we aim to identify and evaluate the literature documenting the outcomes associated with non-pharmacological interventions to improve nighttime sleep among long-term care residents. METHODS: The Preferred Reporting Items for Systematic Reviews guided searches of five databases (MEDLINE, Embase, CINAHL, Scopus, and Cochrane Library) for articles reporting results of experimental or quasi-experimental studies conducted in long-term care settings (nursing homes, assisted-living facilities, or group homes) in which nighttime sleep was subjectively or objectively measured as a primary outcome. We categorized each intervention by its intended use and how it was administered. RESULTS: Of the 54 included studies evaluating the effects of 25 different non-pharmacological interventions, more than half employed a randomized controlled trial design (n = 30); the others used a pre-post design with (n = 11) or without (n = 13) a comparison group. The majority of randomized controlled trials were at low risk for most types of bias, and most other studies met the standard quality criteria. The interventions were categorized as environmental interventions (n = 14), complementary health practices (n = 12), social/physical stimulation (n = 11), clinical care practices (n = 3), or mind-body practices (n = 3). Although there was no clear pattern of positive findings, three interventions had the most promising results: increased daytime light exposure, nighttime use of melatonin, and acupressure. CONCLUSIONS: Non-pharmacological interventions have the potential to improve sleep for residents of long-term care facilities. Further research is needed to better standardize such interventions and provide clear implementation guidelines using cost-effective practices.

An Integrative Review of Nonpharmacological Interventions to Improve Sleep among Adults with Advanced Serious Illness.

BACKGROUND: Sleep fragmentation is common among those with advanced serious illness. Nonpharmacological interventions to improve sleep have few, if any, adverse effects and are often underutilized in these settings. OBJECTIVE: We aimed to summarize the literature related to nonpharmacological interventions to improve sleep among adults with advanced serious illness. METHODS: We systematically searched six electronic databases for literature reporting sleep outcomes associated with nonpharmacological interventions that included participants with advanced serious illness during the period of 1996-2016. RESULTS: From a total of 2731 results, 42 studies met the inclusion criteria. A total of 31 individual interventions were identified, each evaluated individually and some in combination with other interventions. Twelve of these studies employed either multiple interventions within an intervention category (n = 8) or a multicomponent intervention consisting of interventions from two or more categories (n = 5). The following intervention categories emerged: sleep hygiene (1), environmental (6), physical activity (4), complementary health practices (11), and mind-body practices (13). Of the 42 studies, 22 demonstrated a statistically significant, positive impact on sleep and represented each of the categories. The quality of the studies varied considerably, with 17 studies classified as strong, 17 as moderate, and 8 as weak. CONCLUSIONS: Several interventions have been demonstrated to improve sleep in these patients. However, the small number of studies and wide variation of individual interventions within each category limit the generalizability of findings. Further studies are needed to assess interventions and determine effectiveness and acceptability.

Alert Workplace From Healthcare Workers' Perspective: Behavioral and Environmental Strategies to Improve Vigilance and Alertness in Healthcare Settings.

OBJECTIVE: This study aims to identify the behavioral and environmental strategies that healthcare workers view as helpful for managing sleepiness, improving alertness, and therefore optimizing workplace safety. BACKGROUND: Reduced alertness is a common issue in healthcare work environments and is associated with impaired cognitive performance and decision-making ability as well as increased errors and injuries. METHOD: We surveyed 136 healthcare professionals at a primary care clinic, an acute care hospital, and a mental health clinic. Nonstructured, semistructured, and structured questionnaires were used to elicit relevant information which was analyzed using qualitative content analysis and logistic regression models, respectively. RESULTS: In order by frequency of endorsement: dietary intervention; physical mobility; cognitive, sensory, or social stimulation; personal lifestyle strategies; and rest/nap opportunities were reported as behavioral strategies used to address workplace alertness. Compared to other environmental features, daylight and thermal comfort were perceived to be more important to addressing workplace alertness ( p < .05). CONCLUSIONS: By optimizing the physical environment and organizational policies and providing education programs, we have an opportunity to support healthcare professionals in managing sleepiness and maintaining alertness at work. In addition, such system level interventions may reduce unhealthy choices such as frequent caffeine intake to keep alert. The development of multidisciplinary evidence-based guidelines is needed to address sleepiness and alertness to improve workplace safety in healthcare facilities.

Heart rate variability in restless legs syndrome and periodic limb movements of Sleep.

INTRODUCTION: The relationship between the autonomic nervous system and restless legs syndrome (RLS) and periodic limb movements of sleep (PLMS) consists of varied and somewhat conflicting reports. In order to further elucidate these complexities, a retrospective analysis of polysomnography (PSG) records and clinical data was performed. METHODS: Records from 233 adult subjects were randomly selected and organized into one of four groups ("non-RLS/PLMS" [n=61], "RLS" [n=60], "PLMS" [n=58], and "RLS/PLMS" [n=54]). Heart rate variability (HRV) analysis was based on 5-minute samples of 2-lead electrocardiogram data isolated from PSG recordings during wakefulness and NREM sleep, and included mean RR interval (labeled "NN") and standard deviation of the RR intervals (labeled "SDNN"), and HRV power, very low frequency (VLF), low frequency (LF), and high frequency (HF) spectral bands. RESULTS: A significant reduction in the VLF band in the PLMS group as compared to the non-RLS/PLMS group (542±674 vs. 969±1025 ms2, p=0.038) was found in wakefulness. Statistically significant differences were seen in the PLMS group as compared to the non-RLS/PLMS group with a reduction in SDNN (p=0.001) and the HF (p=0.001) band, and an increase in HRV power (p=0.001), and the VLF (p=0.005) and LF (p=0.001) bands in NREM sleep. CONCLUSIONS: The PLMS group exhibited reduced basal sympathetic activity in wakefulness, but basal sympathetic predominance during NREM sleep, distinguishing this group from the RLS and RLS/PLMS groups.