Preschoolers with recurrent wheezing have a high prevalence of sleep disordered breathing.

Objective: Sleep-disordered breathing (SDB) is highly prevalent in school children with poorly-controlled asthma. However, this association has not been assessed in preschoolers with recurrent wheeze, nor in those at risk for asthma. We hypothesized that preschoolers with asthma risk (positive asthma predictive index [API]) have a higher prevalence of SDB and higher inflammatory biomarkers (blood-hsCRP and urinary-LTE4) levels than those with negative API.Method: Children 2 to 5 years of age with recurrent wheezing were classified as positive or negative API. SDB was determined by the pediatric sleep questionnaire (PSQ) and its subscale (PSQSub6). Demographic characteristics, spirometry, blood hsCRP and urinary LTE4 were assessed.Results: We enrolled 101 preschoolers: 70 completed all measurements, 55.4% were males, mean age 4.07 ± 0.87 years, 45% overweight or obese, 70% had positive API, 87.5% had rhinitis. The prevalence of SDB measured by PSQ was 40.8% and by PSQSub6 was 29.6%. However, the proportion of SDB was similar between positive and negative API groups. The hsCRP (mean ± SD) was higher in the positive than in negative API (3.58 ± 0.58 and 1.32 ± 0.36 mg/L, p = 0.69, respectively); moreover, no differences in urinary LTE4 were found between groups. No correlation of PSQ (+) or PSQSub6 (+) with hsCRP and uLTE4 was found. However, preschoolers with positive API had significantly more post-bronchodilator percentage change in FEF25-75 than negative API (24.14 ± 28.1 vs. 4.13 ± 21.8, respectively, p = 0.01).Conclusions: In preschoolers with recurrent wheezing, we should be investigating for the coexistence of SDB, using early screening methods for detecting those conditions.

[Bad sleeping habits in infants: Risk factor for sudden infant death syndrome. Pilot study]. / Malos hábitos de sueño en lactantes: Factor de riesgo para síndrome de muerte súbita del lactante. Estudio piloto.

INTRODUCTION: The American Academy of Pediatrics recommends, through the implementation of the "Back to Sleep (BTS)" campaign, the supine sleeping position for infant sleeping since it prevents to prevent Sudden Infant Death Syndrome (SIDS). OBJECTIVE: To describe the sleeping position of a group of infants and the risk factors associated with sudden infant death syndrome (SIDS). SUBJECTS AND METHOD: Prospective pilot study, including infants < 45 days of life in well-child care visits at a medical center. EXCLUSION CRITERIA: Preterm-born infant (gestational age < 37 weeks) and/or comorbidities (pulmonary, metabolic, cardiologic). A brief parental questionnaire was conducted regarding general demographic data and sleep habits. The questioner was based on the BISQ - Spanish version, due to the lack of validated instruments for infants < 3-month-old. RESULTS: We included a sample of 100 infants between 16.78 ± 12.88 days old (57% girls). Mothers were the main information source (84%). 79% of the infants slept in supine position, 19% slept on their sides, and 2% in prone position. Regarding the place where the infants slept, 66% did in their crib in the parents' room and 31% slept in parents' bed. 74% of infants fell asleep while being fed. 28% of infants were exposed to passive smoking at home. 91% of parents were informed about safe sleep positions, reporting that pediatricians were the main source of information (54%). Conclu sion: We found a high percentage of infants < 45 days of life who slept in an unsafe position, and frequently co-sleep with their parents. Thus, it is important to implement local SIDS prevention campaigns to reinforce safe infant sleep.

Nocturnal Oximetry-based Evaluation of Habitually Snoring Children.

RATIONALE: The vast majority of children around the world undergoing adenotonsillectomy for obstructive sleep apnea-hypopnea syndrome (OSA) are not objectively diagnosed by nocturnal polysomnography because of access availability and cost issues. Automated analysis of nocturnal oximetry (nSpO2), which is readily and globally available, could potentially provide a reliable and convenient diagnostic approach for pediatric OSA. METHODS: Deidentified nSpO2 recordings from a total of 4,191 children originating from 13 pediatric sleep laboratories around the world were prospectively evaluated after developing and validating an automated neural network algorithm using an initial set of single-channel nSpO2 recordings from 589 patients referred for suspected OSA. MEASUREMENTS AND MAIN RESULTS: The automatically estimated apnea-hypopnea index (AHI) showed high agreement with AHI from conventional polysomnography (intraclass correlation coefficient, 0.785) when tested in 3,602 additional subjects. Further assessment on the widely used AHI cutoff points of 1, 5, and 10 events/h revealed an incremental diagnostic ability (75.2, 81.7, and 90.2% accuracy; 0.788, 0.854, and 0.913 area under the receiver operating characteristic curve, respectively). CONCLUSIONS: Neural network-based automated analyses of nSpO2 recordings provide accurate identification of OSA severity among habitually snoring children with a high pretest probability of OSA. Thus, nocturnal oximetry may enable a simple and effective diagnostic alternative to nocturnal polysomnography, leading to more timely interventions and potentially improved outcomes.

[Prevalence and risk factors for sleep-disordered breathing in chilean schoolchildren]. / Trastornos respiratorios del sueño en niños escolares chilenos: prevalencia y factores de riesgo.

OBJECTIVES: To describe the prevalence of sleep-disordered breathing (SDB) in Chilean schoolchil dren and study associated risk factors. PATIENTS AND METHOD: We carried out a transversal and des criptive study. Questionnaires were sent to the parents of children attending first year of elementary school in the Metropolitan Region (Santiago), the Biobío Region (Concepción, Chillán, Yumbel) and the Magallanes Region (Porvenir and Puerto Natales). Anthropometric data, school performan ce, household characteristics, indoor pollutants, medical history, and current symptoms of asthma, allergic rhinitis, and atopic dermatitis were recorded. The nutritional status was determined accor ding to z-BMI. A pediatric sleep questionnaire validated in Spanish (PSQ) was applied. RESULTS: 564 questionnaires were analyzed, the median age was six years (range 5 to 9), 44.9% male. The SDB prevalence was 17.7% (n = 100): 6% in Vitacura (Metropolitan Region), 28.7% in Chillán (Biobío Region), and 36.4% in Puerto Natales (Magallanes Region) (p = 0.001). The group with SDB had a higher proportion of men (54.5 vs 42.8%, p = 0.033), lower academic performance (overall grade point average 6.36 ± 0.48 vs 6.56 ± 0.34, p = 0.001), lower maternal higher education (44.4% vs 69.9%, p = 0.001), and higher exposure to indoor pollutants than those without SDB. After the multivariate analysis, symptoms of rhinitis in the last 12 months (OR 4.79, 95% CI 2.20-10.43) and lower maternal educational level (OR 3.51; 95% CI 1.53-8.02) remained as predictors of SDB. Con clusions: Chilean schoolchildren have a high prevalence of SDB with demographic differences. It was associated with social risk factors, more specific factors of lung damage, and worse sleep quality and quantity.

Relation between asthma and sleep disordered breathing in children: is the association causal?

Over the last few decades, asthma and sleep disordered breathing (SDB) in children have experienced similar increases in prevalence, and have both been shown to have airway inflammation, leading investigators to postulate an association between asthma and SDB. However, whether this relationship is causal or not needs to be proven. In this manuscript, we use the most widely accepted epidemiologic criteria for causality, the Bradford Hill criteria, to test step-by-step whether the relation between asthma and SBD in children is causal or not. We found studies supporting 8 of the 9 criteria (strength, consistency, specificity, biological gradient, coherence and biological plausibility, experiment, and analogy) for association between asthma and SDB. However, we did not find any study showing temporality or directionality between asthma and SDB. Therefore, establishing a causal association between asthma and SDB is not yet possible.

[Diagnosis of respiratory sleep disorders in newborns with suspected apneas: comparison between nocturnal saturometry and polygraphy]. / Diagnóstico de los trastornos respiratorios del sueño en recién nacidos con sospecha de apneas: comparación entre la saturometría nocturna y la poligrafía.

INTRODUCTION: Night Continuous Saturometry (CSO2) is used in Neonatal Units to detect events of hypoxemia in Newborns (NB) with apnea episodes. Polygraphy (PG) has a larger number of measuring channels. Our goal was to evaluate the diagnostic performance of CSO2 compared to Polygra phy in NB with suspected sleep apneas. PATIENTS AND METHOD: Results of CSO2 and PG performed simultaneously in RN with suspected apneas were retrospectively analyzed over a three-year period. A 2-channel Masimo Radical-7® pulse oximeter and an Apnea Link Plus® polygraph with 5 simulta neous recording channels were used. Altered PG was defined as: desaturation index under 80% per hour > 1 and/or number of desaturations under 80% > 20 seconds greater than one in the whole va lidated registry and/or hypoapnea apnea index > 1 event per hour. In parallel, altered SpO2C was de fined when one or both of the 80% saturation criteria were altered. Sensitivity, specificity, predictive values and Likelihood Ratio (LLR) for CSO2 were calculated. Results were expressed in absolute value, with 95% confidence interval. RESULTS: Simultaneous 40 CSO2 and PG were performed; 80% (32/40) of them were preterm infants, 60% (24/40) males. 38% (15/40) of the CSO2 and 15% (6/40) of the PGs were altered (p < 0.05). CSO2 has a 100% Sensitivity, 74% Specificity, 40% VPP, 100% VPN, LLR + 3.78 and LLR-0. CONCLUSION: In the studied NB, CSO2 has a high diagnostic value, however, it may present false positives; It is suggested to use as a screening method and to perform diagnostic confirmation with another sleep test, such as PG.

[Polygraphy in hospitalized children under 3 months]. / Poligrafía en menores de 3 meses hospitalizados.

Apnea and apparently lethal events have great etiological diversity thus complementary tests may help diagnosis. The aim of this study was to describe the results of polygraph studies of children under 3 months hospitalized with suspected apnea. PATIENTS AND METHODS: Retrospective case series. Children under 3 months with suspected apnea were considered and in whom a polygraphy (PG) was performed during hospitalization. General data, the apnea/hypopnea index (AHI), index of central. apnea, obstructive apnea index, average and minimum saturation were recorded. Desaturation index (ID) below 80% higher 1 per hour, one or more events of desaturation below 80% for more than 20 seconds or an AHI greater than or equal 1 were considered as criteria of sleep disorder breathing (SLB). Descriptive analysis was performed and the associations between AHI and saturation parameters were determined. RESULTS: 51 patients, 32 males, entered the study. 15,6% had altered PG. In 5 of them coexisted more than one diagnostic criterion. Iin 15,6% of the patients was observed an IAH greater 1, in 7.8% a desaturation index below 80% and in 11,8% a desaturation index under 80% for 20 seconds greater than 1. The AHI was associated with the parameters of saturation. CONCLUSION: Most of the patients had normal PG and among patients with a suggestive SLB a pattern of respiratory immaturity prevailed, which is characteristic of this age.

Elevated IL-3 and IL-12p40 levels in the lower airway of infants with RSV-induced bronchiolitis correlate with recurrent wheezing.

Respiratory Syncytial Virus (RSV) is the first cause of hospitalization due to bronchiolitis in infants. RSV bronchiolitis has been linked to asthma and recurrent wheezing, however the mechanisms behind this association have not been elucidated. Here, we evaluated the cytokine and chemokine profiles in the airways in infants with RSV bronchiolitis. Nasopharyngeal Aspirates (NPA) and Bronchoalveolar Lavage Fluids (BALF) from infants hospitalized due to RSV bronchiolitis and healthy controls were analyzed for cytokine and chemokine production. We observed elevated levels of Th2 cytokines (IL-3, IL-4, IL-10 and IL-13), pro-inflammatory cytokines and chemokines (IL-1ß, IL-6, TNF-ß, MCP-1/CCL2, MIP-1α/CCL3 and IL-8/CXCL8) in BALF from infants with RSV bronchiolitis, as compared to controls. We found a direct correlation of IL-3 and IL-12p40 levels with the development of recurrent wheezing later in life. These results suggest that IL-3 and IL-12p40 could be considered as molecular predictors for recurrent wheezing due to RSV infection.

Spirometry interpretation feasibility among pre-school children according to the European Respiratory Society and American Thoracic Society Guidelines / Factibilidad de la interpretación de espirometrías en preescolares según criterios ATS/ERS.

INTRODUCTION: Spirometry is the most used test to evaluate pulmonary function. Guidelines that defined acceptability and repeatability criteria for its implementation and interpretation among preschoolers were published in 2007. Our objective was to quantify the actual compliance with these criteria among pre-school patients. METHODS: A review was performed on the baseline spirometry measured in patients aged 2 to 5 years in the Pediatric Respiratory Laboratory of the Pontificia Universidad Católica de Chile, who were admitted due to recurrent or persistent coughing or wheezing. Only those results obtained in patients who took the test for the first time were considered. They were analyzed by international standards. RESULTS: A total of 93 spirometry results (mean age 57.4 ± 8.6 months, 48 males) were obtained, of which 44 (47%) met all acceptable criteria, 87 (93%) obtained expiratory time of ≥ 0.5seconds, and 67 (72%) of the patients had an end-expiratory flow of ≤10% from peak flow. The variation in the measurement of forced vital capacity (FVC) and forced expiratory volume in one second (FEV1) was very low (intraclass correlation coefficient > 0.9). CONCLUSION: It was possible to meet the acceptability and repeatability criteria for spirometry among pre-school children in our Center, which was similar to previous reports. As in older children, this test is fully recommended for pre-school children who require lung function studies.

Treatment of obstructive sleep apnea in infants with trisomy 21 using oral appliances.

Objective : To perform a retrospective study to evaluate the effect of oral appliances, aimed at increasing the pharyngeal space, on obstructive sleep apnea (OSA) in infants with trisomy 21 (TS21). Design and Setting : Retrospective study in a tertiary referral center. Intervention : We analyzed data from 51 consecutive infants (mean age, 2.7 months) who underwent polysomnography (PSG) and were offered our treatment concept. Primary study variable was the mixed-obstructive apnea index (MOAI); OSA was defined as a MOAI ≥ 1. Results : Twenty-seven infants (53%) had OSA. Their median MOAI improved from 2.3 (1 to 13) to 0 (0 to 0.2; P < .05). Seven of these infants were treated with an appliance that included some type of velar extension to move the tongue base forward. Of the 24 infants without OSA at admission, follow-up PSG results were available for 13. Three infants from this group had developed OSA by the time of a repeat PSG. Conclusion : In patients with TS21, OSA may already develop in infancy. Early treatment may improve OSA. Oral appliances with some type of velar extension may be considered as an alternative to other treatment procedures.

[Prevalence of sudden death syndrome among children]. / Síndrome de muerte súbita del lactante: prevalencia y cambios en los últimos años en Chile.

BACKGROUND: The sudden infant's death syndrome (SD) is the leading cause of death in children under one year. Despite advances in its study, the pathogenesis has not been yet fully elucidated. AIM: To assess the prevalence of SD in Chilean infants and its changes in recent years. MATERIAL AND METHODS: Review of birth and death databases of the Ministry of Health from 1997 to 2009. All cases diagnosed as SD, according to the lnternational Classification of Diseases, 10th edition, were selected. A demographic analysis was performed and mortality rates for each year were calculated. RESULTS: We identified 1442 cases of SD (847 males, 517 deaths at home). The median age of death was 2 months (0 to 11.0 months). Ninety six percent of deaths occurred in children aged <6 months. Mortality rate for SD was 0.45/1000 live births. There was a 23% reduction between 1997 and 2009. When analyzing geographic distribution, more cases were found in the Southern latitudes of the country. CONCLUSIONS: The overall rate of SD in Chile is higher than in European countries and in North America. The observed decrease in cases over the years is still far from optimal.

[Studies of sleep and therapeutic actions in children and adolescents with craniofacial anomalies]. / Estudios de sueño y conducta terapéutica en niños y adolescentes con alteraciones craneofaciales.

OBJECTIVE: To describe the presence of obstructive sleep apnea syndrome (OSAS) in children with craniofacial anomalies (CFA), associate biodemographic characteristics and polygraph variables, and analyze the therapeutic management decided after the sleep study and the evaluation by a multidisciplinary team. PATIENTS AND METHOD: Retrospective study. Polygraphs were performed on patients aged between 1 month and 19 years with CFA. An initial and projected management was established categorized into ventilatory support, tracheostomy, surgery, dental, and medical treatment. Descrip tive and inferential statistics were performed, evaluating the association between demographic and polygraph variables and therapeutic management. RESULTS: 34 patients were included with a median age of 4.0 years (IQR 0.9 - 6.5). Diagnosis was 41.2% cleft lip and palate, 35.3% craniosynostosis, and 23.5% micrognathia. Polygraphs were altered in 70.6% of the cases; of these, 26.5% were diagnosed as mild, 5.9% moderate, and 38.2% severe OSAS. There was an association between minimum satu ration and diagnosis of OSAS (p = 0.0036), and in the presence of OSAS with the initial management applied (p=0.0013). There was no significant relationship between the different types of CFA with the initial therapeutic management (p = 0.6565). Initial and projected managements, respectively: Venti latory support (11.8% and 2.9%), tracheostomy (11.8% and 0%), surgery (35.2% and 26.5%), dental (20.6% and 53%), and medical treatment (20.6% and 17.6 %). CONCLUSIONS: 70% of the patients with CFA presented OSAS. The greatest severity was found in Cleft Lip and Palatine and Craniosynostosis. Therapeutic management was mainly oriented towards initial surgical and planned dental treatments based on the diagnosis of OSAS and not on the type of CFA.

Improve sleep in critically ill patients: Study protocol for a randomized controlled trial for a multi-component intervention of environment control in the ICU.

INTRODUCTION: In critically ill patients, sleep and circadian rhythms are greatly altered. These disturbances have been associated with adverse consequences, including increased mortality. Factors associated with the ICU environment, such as exposure to inadequate light and noise levels during the day and night or inflexible schedules of daily care activities, have been described as playing an essential role in sleep disturbances. The main objective of this study is to evaluate the impact of the use of a multifaceted environmental control intervention in the ICU on the quantity and quality of sleep, delirium, and post-intensive care neuropsychological impairment in critically ill patients. METHODS: This is a prospective, parallel-group, randomized trial in 56 critically ill patients once they are starting to recover from their acute illness. Patients will be randomized to receive a multifaceted intervention of environmental control in the ICU (dynamic light therapy, auditory masking, and rationalization of ICU nocturnal patient care activities) or standard care. The protocol will be applied from enrollment until ICU discharge. Baseline parameters, light and noise levels, polysomnography and actigraphy, daily oscillation of plasma concentrations of Melatonin and Cortisol, and questionnaires for the qualitative evaluation of sleep, will be assessed during the study. In addition, all patients will undergo standardized follow-up before hospital discharge and at 6 months to evaluate neuropsychological impairment. DISCUSSION: This study is the first randomized clinical trial in critically ill patients to evaluate the effect of a multicomponent, non-pharmacological environmental control intervention on sleep improvement in ICU patients. The results will provide data about the potential synergistic effects of a combined multi-component environmental intervention in ICU on outcomes in the ICU and long term, and the mechanism of action. TRIAL REGISTRATION: ClinicalTrials.gov, NCT. Registered on January 10, 2023. Last updated on 24 Jan 2023.

Primary snoring in school children: prevalence and neurocognitive impairments.

PURPOSE: We aimed to investigate the prevalence of primary snoring (PS) and its association with neurocognitive impairments. METHODS: Data from a community-based study in 1,114 primary school children were used to identify children who never (N = 410) or habitually snored (N = 114). In order to separate children with PS from those with upper airway resistance syndrome (UARS) or obstructive sleep apnoea (OSA), home polysomnography was conducted in all habitually snoring children. Neurocognitive impairments and poor school performance were compared between children who never snored, PS, and UARS/OSA. RESULTS: Polysomnography was successfully conducted in 92 habitual snorers. Of these, 69 and 23 had PS and UARS/OSA, respectively. Prevalence [95% confidence interval (95% CI)] of PS was 6.1% (4.5-7.7). Compared to children who had never snored, children with PS had more hyperactive (39% vs. 20%) and inattentive behaviour (33% vs. 11%), as well as poor school performance in mathematics (29% vs. 16%), science (23% vs. 12%), and spelling (33% vs. 20%; all P values <0.05). PS was a significant risk factor (odds ratio; 95% CI) for hyperactive behaviour (2.8; 1.6-4.8), inattentive behaviour (4.4; 2.4-8.1), as well as daytime sleepiness (10.7; 4.0-28.4). PS was also an independent risk factor for poor school performance in mathematics (2.6; 1.2-5.8), science (3.3; 1.2-8.8), and spelling (2.5; 1.1-5.5). Odds ratios throughout were similar to the UARS/OSA group. CONCLUSIONS: Children with non-hypoxic, non-apnoeic PS may exhibit significant neurocognitive impairments. Consequences may be similar to those associated with UARS or OSA. If confirmed, PS is not "benign" and may require treatment.

Neurocognitive Consequences in Children with Sleep Disordered Breathing: Who Is at Risk?

Sleep-disordered breathing (SDB) is a prevalent disease in children characterized by snoring and narrowing of the upper airway leading to gas exchange abnormalities during sleep as well as sleep fragmentation. SDB has been consistently associated with problematic behaviors and adverse neurocognitive consequences in children but causality and determinants of susceptibility remain incompletely defined. Since the 1990s several studies have enlightened these associations and consistently reported poorer academic performance, lower scores on neurocognitive tests, and behavioral abnormalities in children suffering from SDB. However, not all children with SDB develop such consequences, and severity of SDB based on standard diagnostic indices has often failed to discriminate among those children with or without neurocognitive risk. Accordingly, a search for discovery of markers and clinically useful tools that can detect those children at risk for developing cognitive and behavioral deficits has been ongoing. Here, we review the advances in this field and the search for possible detection approaches and unique phenotypes of children with SDB who are at greater risk of developing neurocognitive consequences.

Risk factors and consequences of excessive autonomic activation during sleep in children.

PURPOSE: The aim of this study was to assess risk factors for excessive autonomic activation during sleep (EAAS) and its association with sleep problems, impaired behavior, and poor academic performance in primary school children. METHODS: Data from a community-based study on 997 primary school children were used. Based on nocturnal home pulse oximetry, autonomic activation during sleep was defined as a pulse rate increase by more than 20%. Children with ≥35.9 autonomic activations per hour (i.e., ≥ the 95(th) centile) were classified as suffering from EAAS and compared with controls. Sleep problems, impaired behavior, and academic performance were assessed by parental questionnaires and analysis of school reports. RESULTS: According to the above-mentioned definition, EAAS was diagnosed in 52 children (67% male). Risk factors for EAAS were male gender (odds ratio [95% confidence interval]: 2.06 [1.14-3.72]) and presence of symptoms of sleep-disordered breathing (3.48 [1.29-9.43]). Children with EAAS had a higher prevalence of hyperactive behavior (39.2% vs. 26.0%; p = 0.05) and enuresis (5.8% vs. 0.8%; p = 0.017) but not of poor academic performance. The association with hyperactive behavior was confirmed in a subsample (n = 119) using the Strengths and Difficulties Questionnaire. Mean (SD) score of the hyperactive-inattentive scale was 4.5 (2.8) for EAAS and 3.4 (2.7) for non-EAAS (p = 0.04). CONCLUSION: EAAS may be a marker of sleep disruption in children and may predict the occurrence of enuresis and hyperactive behavior.

Alternatives to surgery in children with mild OSA.

Precision medicine requires coordinated and integrated evidence-based combinatorial approaches so that diagnosis and treatment can be tailored to the individual patient. In this context, the treatment approach to mild obstructive sleep apnea (OSA) is fraught with substantial debate as to what is mild OSA, and as to what constitutes appropriate treatment. As such, it is necessary to first establish a proposed consensus of what criteria need to be employed to reach the diagnosis of mild OSA, and then examine the circumstances under which treatment is indicated, and if so, whether and when anti-inflammatory therapy (AIT), rapid maxillary expansion (RME), and/or myofunctional therapy (MFT) may be indicated.

Past, present, and future of sleep medicine research in Latin America.

NONE: Sleep medicine is a relatively young field with exponential growth in development and research in the last decades. Parallel to the advances in the United States, Latin America also had its beginnings in sleep medicine housed in neuroscience laboratories. Since the very first Latin American meeting in 1985, and the first sleep society in 1993, sleep research has undergone significant development in subsequent years. From contributions in animal research that allowed understanding of the activity of the brain during sleep to the studies that improved our knowledge of sleep disorders in humans, Latin America has become a scientific hub for expansion of sleep research. In this article, we present a historical account of the development of sleep medicine in Latin America, the current state of education and the achievements in research throughout history, and the latest advances in the trending areas of sleep science and medicine. These findings were presented during World Sleep Society meeting in Vancouver in 2019 and complement the work on sleep societies and training published by Vizcarra-Escobar et al in their article "Sleep societies and sleep training programs in Latin America" (J Clin Sleep Med. 2020;16(6):983-988).

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

OBJECTIVE: To analyze and identify differences in sleep spindles in children with restless sleep disorder (RSD), restless legs syndrome (RLS) and normal controls. METHODS: PSG (polysomnography) from children with RSD, RLS and normal controls were analyzed. Sleep spindle activity was detected on one frontal and one central electrode, for each epoch of N2 and N3 sleep. Sleep spindle density, duration and intensity (density × duration) were then obtained and used for analysis. RESULTS: Thirty-eight children with RSD, twenty-three children with RLS and twenty-nine controls were included. The duration of frontal spindles in sleep stage N2 was longer in children with RSD than in controls. Frontal spindle density and intensity tended to be increased in RSD children. No significant differences were found for central spindles. CONCLUSION: Children with RSD had longer frontal spindles. This finding may contribute to explain the occurrence of excessive movement activity during sleep and the presence of daytime symptoms. SIGNIFICANCE: Recent research has demonstrated that children with RSD have increased NREM instability and sympathetic activation during sleep. Analyzing sleep spindles in children with RSD in comparison with children with RLS and controls adds to our understanding of the pathophysiology or RSD and its effects on daytime impairment.

Association of sleep spindle activity and sleepiness in children with sleep-disordered breathing.

STUDY OBJECTIVES: The association of snoring and sleep-disordered breathing (SDB) with daytime sleepiness is well documented; however, the exact mechanisms, and especially the role of sleep microstructure that may account for this association remain incompletely understood. In a cohort of children with SDB, we aimed to compare sleep spindle activity between children with daytime sleepiness versus those without daytime sleepiness. METHODS: Children with SDB who reported daytime sleepiness were recruited and compared with age- and sex-matched SDB controls. Polysomnographic recordings were analyzed evaluating sleep spindle activity. A statistical comparison was carried out in both groups to assess the association between sleepiness and sleep spindle activity. RESULTS: Thirty-three children with SDB (mean age: 7.5 ± 1.7 years) were included, 10 with and 23 without daytime sleepiness. Spindle activity was lower in children with daytime sleepiness compared with those without; in stage N2, median (interquartile range) sleep spindle indexes were 77.5 (37.3) and 116.9 (71.2) (P = .015), respectively. CONCLUSIONS: Spindles were significantly reduced in children with SDB and daytime sleepiness. The exact mechanisms of this association remain unknown and future research is needed in order to establish the exact role of sleep spindle activity on daytime symptoms in children with SDB.