Four State Sleep Staging From a Multilayered Algorithm Using Electrocardiographic and Actigraphic Data.

PURPOSE: Sleep studies are important to evaluate sleep and sleep-related disorders. The standard test for evaluating sleep is polysomnography, during which several physiological signals are recorded separately and simultaneously with specialized equipment that requires a technologist. Simpler recordings that can model the results of a polysomnography would provide the benefit of expanding the possibilities of sleep recordings. METHODS: Using the publicly available sleep data set from the multiethnic study of atherosclerosis and 1769 nights of sleep, we extracted a distinct data subset with engineered features of the biomarkers collected by actigraphic, oxygenation, and electrocardiographic sensors. We then applied scalable models with recurrent neural network and Extreme Gradient Boosting (XGBoost) with a layered approach to produce an algorithm that we then validated with a separate data set of 177 nights. RESULTS: The algorithm achieved an overall performance of 0.833 accuracy and 0.736 kappa in classifying into four states: wake, light sleep, deep sleep, and rapid eye movement (REM). Using feature analysis, we demonstrated that heart rate variability is the most salient feature, which is similar to prior reports. CONCLUSIONS: Our results demonstrate the potential benefit of a multilayered algorithm and achieved higher accuracy and kappa than previously described approaches for staging sleep. The results further the possibility of simple, wearable devices for sleep staging. Code is available at https://github.com/NovelaNeuro/nEureka-SleepStaging.

Rethinking bedtime resistance in children with autism: is restless legs syndrome to blame?

STUDY OBJECTIVES: In this study we investigated the clinical correlates of restless legs syndrome in children with autism and report on our experiences with response to treatment. METHODS: A retrospective chart review of children seen in our sleep center from 2016-2019 was performed to identify children with autism and chronic insomnia. Patients underwent clinical assessments for restless legs symptomatology. Overnight polysomnogram, serum ferritin testing, and response to clinical treatment data were collected. RESULTS: A total of 103 children with autism and chronic insomnia were identified (age range 2-19 years). Of these, 41 children (39%) were diagnosed with restless legs syndrome. The diagnosis of restless legs syndrome was associated with significantly lower serum ferritin levels (mean 29 ± 18.62 ng/mL vs non-restless legs syndrome 56.7 ± 17.59, P < .001) and higher periodic limb movements of sleep on polysomnogram (8.12 ± 6.6 vs non-restless legs syndrome 0.06 ± 0.17). The presence of leg kicking, body rocking, or any symptoms involving the legs was highly correlated with the diagnosis of restless legs syndrome. Positive treatment response was noted in nearly all treated patients, including those treated with oral iron supplementation alone (25 children, 23 responders), gabapentin alone (12 children, all responders), and combination therapy (3 children, all responders). CONCLUSIONS: Our findings suggest restless legs syndrome may represent an under-recognized cause of insomnia in children with autism. Initial assessment should include a thorough query of behaviors related to nocturnal motor complaints, because restless legs syndrome may be a treatable cause of sleep disruption.

Sleep for Stroke Management and Recovery Trial (Sleep SMART): Rationale and methods.

RATIONALE: Obstructive sleep apnea is common among patients with acute ischemic stroke and is associated with reduced functional recovery and an increased risk for recurrent vascular events. AIMS AND/OR HYPOTHESIS: The Sleep for Stroke Management and Recovery Trial (Sleep SMART) aims to determine whether automatically adjusting continuous positive airway pressure (aCPAP) treatment for obstructive sleep apnea improves clinical outcomes after acute ischemic stroke or high-risk transient ischemic attack. SAMPLE SIZE ESTIMATE: A total of 3062 randomized subjects for the prevention of recurrent serious vascular events, and among these, 1362 stroke survivors for the recovery outcome. METHODS AND DESIGN: Sleep SMART is a phase III, multicenter, prospective randomized, open, blinded outcome event assessed controlled trial. Adults with recent acute ischemic stroke/transient ischemic attack and no contraindication to aCPAP are screened for obstructive sleep apnea with a portable sleep apnea test. Subjects with confirmed obstructive sleep apnea but without predominant central sleep apnea proceed to a run-in night of aCPAP. Subjects with use (≥4 h) of aCPAP and without development of significant central apneas are randomized to aCPAP plus usual care or care-as-usual for six months. Telemedicine is used to monitor and facilitate aCPAP adherence remotely. STUDY OUTCOMES: Two separate primary outcomes: (1) the composite of recurrent acute ischemic stroke, acute coronary syndrome, and all-cause mortality (prevention) and (2) the modified Rankin scale scores (recovery) at six- and three-month post-randomization, respectively. DISCUSSION: Sleep SMART represents the first large trial to test whether aCPAP for obstructive sleep apnea after stroke/transient ischemic attack reduces recurrent vascular events or death, and improves functional recovery.

Multidisciplinary sleep centers: strategies to improve care of sleep disorders patients.

Current emphasis on patient outcomes within sleep medicine, with a particular focus on quality improvement and contained costs, calls for sleep specialists to develop innovative models for long-term care and management of sleep disorders patients. Multidisciplinary sleep centers can facilitate highest-quality care that is timely and cost-effective. Effective resource use in a multidisciplinary sleep center can help minimize fragmentation of care, reduce effort duplication, and control costs. Proposed strategies to help achieve a balance between quality of care and cost-effectiveness include: (1) multidisciplinary specialty clinics, (2) optimized use of information technology, and (3) adoption of reliable performance measures.

Pediatric restless legs syndrome diagnostic criteria: an update by the International Restless Legs Syndrome Study Group.

BACKGROUND: Specific diagnostic criteria for pediatric restless legs syndrome (RLS) were published in 2003 following a workshop at the National Institutes of Health. Due to substantial new research and revision of the adult RLS diagnostic criteria, a task force was chosen by the International Restless Legs Syndrome Study Group (IRLSSG) to consider updates to the pediatric diagnostic criteria. METHODS: A committee of seven pediatric RLS experts developed a set of 15 consensus questions to review, conducted a comprehensive literature search, and extensively discussed potential revisions. The committee recommendations were approved by the IRLSSG executive committee and reviewed by the IRLSSG membership. RESULTS: The pediatric RLS diagnostic criteria were simplified and integrated with the newly revised adult RLS criteria. Specific recommendations were developed for pediatric application of the criteria, including consideration of typical words used by children to describe their symptoms. Pediatric aspects of differential diagnosis, comorbidity, and clinical significance were then defined. In addition, the research criteria for probable and possible pediatric RLS were updated and criteria for a related condition, periodic limb movement disorder (PLMD), were clarified. CONCLUSIONS: Revised diagnostic criteria for pediatric RLS have been developed, which are intended to improve clinical practice and promote further research.

Pediatric restless legs syndrome: analysis of symptom descriptions and drawings.

The specific aims of this study were to collect and analyze detailed symptom descriptions from patients with pediatric restless legs syndrome, ages 6 to 17 years, as well as assess symptom impact and the usefulness of drawings. Trained qualitative interviewers conducted face-to-face audio-recorded interviews of children and adolescents who met criteria for definite restless legs syndrome. Thirty-three patients in 3 age groups used 16 different categories of descriptors for restless legs sensations, with a mean of 3 or more categories used per patient in each age group. "Need to move/kick," "pain/hurts," "uncomfortable/cannot get comfortable," and "like bugs or ants/crawling" were the most common descriptors. Two-thirds reported daytime sensations, and nearly half had arm involvement. They described impact on sleep, cognitive function, and affect. Drawings provided useful diagnostic information. These detailed empirical data will be useful in clinical practice, as well as in the development of formal diagnostic tools and severity measures.

Restless legs syndrome, periodic leg movements, and periodic limb movement disorder in children.

The characteristic symptoms of restless legs syndrome (RLS) have been known for hundreds of years and were first reported in medicine in the 1600s. Clinicians must consider potential mimics, comorbid, and associated conditions when evaluating children with RLS symptoms. The traditional differentiation of RLS from periodic limb movement disorder (PLMD) is noted in children as well as adults. Because current pediatric RLS research is sparse, this article provides the most up-to-date evidence-based as well as consensus opinion-based information on the subject of childhood RLS and PLMD. Prevalence, pathophysiology, diagnosis, treatment, and clinical associations are discussed.

Development of the Pediatric Restless Legs Syndrome Severity Scale (P-RLS-SS): a patient-reported outcome measure of pediatric RLS symptoms and impact.

OBJECTIVE: To develop a questionnaire to measure Pediatric Restless Legs Syndrome (P-RLS) symptoms and impact for use in clinical research. METHODS: Questionnaire items were developed based on open-ended, qualitative interviews of 33 children and adolescents diagnosed with definite RLS (ages 6-17 years) and their parents. The draft questionnaire was then tested through cognitive debriefing interviews with 21 of the same children/adolescents and 15 of their parents. This involved the children and parents answering the draft items and then interviewing them about the child's ability to understand and interpret the questionnaire. Expert clinicians provided clinical guidance throughout. RESULTS: Draft severity questions were generated to measure the four-symptom and four-impact domains identified from the concept elicitation interviews: RLS sensations, move/rub due to RLS, relief from move/rub, pain, and impact of RLS on sleep, awake activities, emotions, and tiredness. RLS descriptions, symptoms, and impact were compared between those who had comorbid attention-deficit/hyperactivity disorder and those who did not. Revisions to several questions were made based on the cognitive debriefing interviews and expert clinician review, resulting in a severity scale with 17 morning and 24 evening items. Caution regarding self-administration in children ages 6-8 years is recommended. To complement the child/adolescent measures, a separate parent questionnaire was also developed. CONCLUSIONS: The P-RLS-SS was constructed based on detailed input from children and adolescents with RLS, their parents, and clinical experts, thus providing a scale with strong content validity that is intended to be comprehensive, clinically relevant, and important to patients. Validation of this scale is recommended.

Neurocognitive consequences of sleep deprivation.

Sleep deprivation is associated with considerable social, financial, and health-related costs, in large measure because it produces impaired cognitive performance due to increasing sleep propensity and instability of waking neurobehavioral functions. Cognitive functions particularly affected by sleep loss include psychomotor and cognitive speed, vigilant and executive attention, working memory, and higher cognitive abilities. Chronic sleep-restriction experiments--which model the kind of sleep loss experienced by many individuals with sleep fragmentation and premature sleep curtailment due to disorders and lifestyle--demonstrate that cognitive deficits accumulate to severe levels over time without full awareness by the affected individual. Functional neuroimaging has revealed that frequent and progressively longer cognitive lapses, which are a hallmark of sleep deprivation, involve distributed changes in brain regions including frontal and parietal control areas, secondary sensory processing areas, and thalamic areas. There are robust differences among individuals in the degree of their cognitive vulnerability to sleep loss that may involve differences in prefrontal and parietal cortices, and that may have a basis in genes regulating sleep homeostasis and circadian rhythms. Thus, cognitive deficits believed to be a function of the severity of clinical sleep disturbance may be a product of genetic alleles associated with differential cognitive vulnerability to sleep loss.

Neurocognitive consequences of sleep deprivation.

Deficits in daytime performance due to sleep loss are experienced universally and associated with a significant social, financial, and human cost. Microsleeps, sleep attacks, and lapses in cognition increase with sleep loss as a function of state instability. Sleep deprivation studies repeatedly show a variable (negative) impact on mood, cognitive performance, and motor function due to an increasing sleep propensity and destabilization of the wake state. Specific neurocognitive domains including executive attention, working memory, and divergent higher cognitive functions are particularly vulnerable to sleep loss. In humans, functional metabolic and neurophysiological studies demonstrate that neural systems involved in executive function (i.e., prefrontal cortex) are more susceptible to sleep deprivation in some individuals than others. Recent chronic partial sleep deprivation experiments, which more closely replicate sleep loss in society, demonstrate that profound neurocognitive deficits accumulate over time in the face of subjective adaptation to the sensation of sleepiness. Sleep deprivation associated with disease-related sleep fragmentation (i.e., sleep apnea and restless legs syndrome) also results in neurocognitive performance decrements similar to those seen in sleep restriction studies. Performance deficits associated with sleep disorders are often viewed as a simple function of disease severity; however, recent experiments suggest that individual vulnerability to sleep loss may play a more critical role than previously thought.