Working memory impairment and its associated sleep-related respiratory parameters in children with obstructive sleep apnea

Summary of drug therapy to treat cognitive impairment-induced obstructive sleep apnea

Obstructive sleep apnea (OSA) is a severe sleep disorder associated with intermittent hypoxia and sleep fragmentation. Cognitive impairment is a signifi- cant and common OSA complication often described in such patients. The most commonly utilized methods in clinical OSA treatment are oral appliances and continuous positive airway pressure (CPAP). However, the current therapeutic methods for improving cognitive function could not achieve the expected efficacy in same patients. Therefore, further understanding the molecular mechanism behind cognitive dysfunction in OSA disease will provide new treatment methods and targets. This review briefly summarized the clinical manifestations of cognitive impairment in OSA disease. Moreover, the pathophysiological molecular mechanism of OSA was outlined. Our study concluded that both SF and IH could induce cognitive impairment by multiple signaling pathways, such as oxidative stress activation, inflammation, and apoptosis. However, there is a lack of effective drug therapy for cognitive impairment in OSA. Finally, the therapeutic potential of some novel compounds and herbal medicine was evaluated on attenuating cognitive impairment based on certain preclinical studies.

Serum neurofilament light reflects cognitive dysfunctions in children with obstructive sleep apnea

Background

In children, obstructive sleep apnea (OSA) can cause cognitive dysfunctions. Amyloid-beta and tau are elevated in OSA. Neurofilament light (NfL) is a marker of neuro-axonal damage, but there are no reports of NfL for OSA. The objective was to investigate the serum levels of NfL and tau in children with or without OSA and explore their relationship with cognitive dysfunctions caused by OSA.

Methods

This retrospective case–control study included children diagnosed with adenoid tonsil hypertrophy from July 2017 to September 2019 at the Second Affiliated Hospital of Xi’an Jiaotong University. Correlations between cognitive scores and tau and NfL were examined.

Results

Fifty-six OSA and 49 non-OSA children were included. The serum NfL levels were higher in the OSA group (31.68 (27.29–36.07) pg/ml) than in the non-OSA group (19.13 (17.32–20.95) pg/ml) (P < 0.001). Moreover, NfL was correlated with the course of the disease, apnea–hypopnea index (AHI), obstructive apnea index (OAI), obstructive apnea–hypopnea index (OAHI), average oxygen saturation (SaO₂), respiratory arousal index (RAI), and cognitive dysfunctions evaluated by the Chinese Wechsler Intelligence Scale for Children (C-WISC) (all P < 0.05). The area under the receiver operating characteristics curve (AUC) of NfL was 0.816 (95%CI: 0.736–0.897). Multiple regression analysis revealed that NfL was significantly associated with verbal intelligence quotient (VIQ), performance intelligence quotient (PIQ) and full-scale intelligence quotient (FIQ) (P < 0.001, respectively).

Conclusions

Serum NfL levels are associated with the severity of cognitive dysfunctions in children diagnosed with adenoid tonsil hypertrophy and might be a candidate noninvasive, objective marker to identify cognitive dysfunctions in children with OSA.

Impact of mask use on face recognition: an eye-tracking study

We examined how mask use affects performance and eye movements in face recognition and whether strategy change reflected in eye movements is associated with performance change. Eighty-eight participants performed face recognition with masked faces either during learning only, during recognition only, or during both learning and recognition. As compared with the baseline condition where faces were unmasked during both learning and recognition, participants had impaired performance in all three scenarios, with larger impairment when mask conditions during learning and recognition did not match. When recognizing unmasked faces, whether the faces were learned with or without a mask on did not change eye movement behavior. Nevertheless, when recognizing unmasked faces that were learned with a mask on, participants who adopted more eyes-focused patterns had less performance impairment as compared with the baseline condition. When recognizing masked faces, participants had more eyes-focused patterns and more consistent gaze transition behavior than recognizing unmasked faces regardless of whether the faces were learned with or without a mask on. Nevertheless, when recognizing masked faces that were learned without a mask, participants whose gaze transition behavior was more consistent had less performance impairment as compared with the baseline condition. Thus, although eye movements during recognition were mainly driven by the mask condition during recognition but not that during learning, those who adjusted their strategy according to the mask condition difference between learning and recognition had better performance. This finding has important implications for identifying populations vulnerable to the impact of mask use and potential remedial strategies.

Exploring the relationship of sleep, cognition, and cortisol in sickle cell disease

Background

Neurocognitive impairment is common in people with Sickle Cell Disease (SCD) and evidence is accumulating that sleep disturbances play a role. The interaction between cortisol and sleep in the general population is associated with cognition as well as general wellbeing but there are few data in SCD. We aimed to understand the relationship between cortisol and sleep in individuals with SCD and explored associations with cognition.

Methods

Forty-five participants of black heritage (SCD: N = 27, 9–29 years, 16 females; Controls: N = 18, 11–25 years, 13 females) were recruited from the community between 2018 - 2020. Participants completed standardized questionnaires about their sleep behaviour and wore actigraphy MotionWatch8 for 7 nights to assess nocturnal sleep patterns. Salivary cortisol samples were taken on wakening and 3 times after 14:00. Cognition was assessed using the Wechsler Intelligence Scales for children and adults.

Results

People with SCD took longer to fall asleep and experienced greater wake bouts, mobile minutes and fragmented sleep compared to controls. Although non-significant, people with SCD experienced lower morning cortisol, with a flattened diurnal cortisol ratio compared to controls. Interestingly, SCD participants, but not controls, with low diurnal variation scored lowest on processing speed (PSI) and perceptual reasoning index (PRI). A moderator analysis revealed that the effect of morning cortisol and diurnal cortisol ratio on PRI by group health (i.e., SCD and healthy controls) depended on sleep quality.

Discussion

Sleep and cortisol may play a crucial role in the expression of cognitive difficulties seen in SCD. This should be considered for the development of interventions to optimise cognitive functioning and sleep. This, in turn, could positively impact on secretion of cortisol and general health in SCD.

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We examined sleep patterns, cortisol and cognition in 27 participants with Sickle Cell Disease (SCD) and 18 healthy controls.

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People with SCD had lower cognitive scores compared to healthy controls.

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People with SCD took longer to fall asleep, had greater wake bouts, mobile minutes, and fragmented sleep.

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People with SCD experienced a flattened diurnal cortisol profile.

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Sleep disturbances might interfere with diurnal cortisol rhythm and contribute to lower cognitive scores .

Self-Reported Sleep and Executive Function in Early Primary School Children

The study investigated the associations between children’s self-reported habitual sleep disturbance and multidimensional executive function (EF). Two hundred and four 7–9-year-old typically developing children completed the Sleep Self-Report and finished the Red-Blue Test, Wisconsin Card Sorting Test, and Backward Digit Span Test, indexing different EF components including inhibitory control, cognitive flexibility, and working memory. Results revealed that all the three EF components were significantly correlated with sleep. However, cognitive flexibility was no longer significantly related to sleep when the other EF components – inhibitory control and working memory – were controlled for. Meanwhile, inhibitory control, as well as working memory, was still significantly related to sleep after controlling for the other EF components. Results suggest that children’s self-reported sleep might be associated directly with inhibitory control and working memory, but indirectly with cognitive flexibility.

Clinical predictors of working memory performance in obstructive sleep apnoea patients before and during extended wakefulness

STUDY OBJECTIVES

Extended wakefulness (EW) and obstructive sleep apnoea (OSA) impair working memory (WM), but their combined effects are unclear. This study examined the impact of EW on WM function in OSA patients and identified clinical predictors of WM impairment.

METHODS

Following polysomnography (PSG), 56 OSA patients (Mean ± SD, age 49.5 ± 8.9, AHI 38.1 ± 25.0) completed WM 2-back performance tasks 10 times over 24 hours of wakefulness to assess average accuracy and completion times measured after 6-12 hours awake (baseline) compared to 18-24 hours awake (EW). Hierarchical cluster analysis classified participants with poorer versus better WM performance at baseline and during EW. Clinical predictors of performance were examined via regression and receiver operator characteristic (ROC) analyses.

RESULTS

WM performance decreased following EW and showed consistent correlations with age, ESS, total sleep time and hypoxemia (O2 nadir and mean O2 desaturation) at baseline and with EW (all p<0.01). O2 nadir and age were significant independent predictors of performance at baseline (adjusted R 2=0.30, p<0.01), while O2 nadir and ESS were predictors of WM following EW (adjusted R 2=0.38, p<0.001). ROC analysis demonstrated high sensitivity and specificity of models to predict poorer vs better performing participants at baseline (83% and 69%) and during EW (84% and 74%).

CONCLUSIONS

O2 nadir, age and sleepiness show prognostic value for predicting WM impairment in both rested and sleep deprived OSA patients and may guide clinicians in identifying patients most at risk of impaired WM under both rested and heightened sleep pressure conditions.

Assessment of event-related evoked potentials and China-Wechsler intelligence scale for cognitive dysfunction in children with obstructive sleep apnea

OBJECTIVE

To explore the relationship between obstructive sleep apnea (OSA) and cognitive impairment by combining event-related evoked potentials (ERPs) and China-Wechsler Younger Children Scale (C-WISC) in children with sleep-disordered breathing (SDB) with vs. without OSA.

METHODS

This was a retrospective case-control study of all consecutive children (n = 148) with adenoid tonsil hypertrophy between July 2017 and March 2019 at the Hospital.

RESULTS

The children were divided into the OSA (n = 102) and non-OSA (n = 46) groups. The apnea-hypopnea index (AHI), obstructive apnea index (OAI), and obstructive apnea-hypopnea index (OAHI) in the OSA group were elevated compared with those of the non-OSA group (all P < 0.001). The mean oxygen saturation (SaO₂) and SaO₂ nadir were lower in the OSA group compared with the non-OSA group (both P < 0.001). The respiratory arousal index (RAI) values in the OSA group were larger than those of the non-OSA group (P < 0.001). The P300 and N100 latencies in the OSA group were longer than those of the non-OSA group (both P < 0.001). Pearson's correlation analysis revealed correlations of the P300 peak latency with full-scale intelligence quotient (FIQ) (P < 0.001 and r = -0.527), verbal intelligence quotient (VIQ) (P < 0.001 and r = -0.448), and performance intelligence quotient (PIQ) (P < 0.001 and r = -0.515). There was a correlation between the N100 peak latency and PIQ (P = 0.026 and r = -0.183).

CONCLUSION

ERPs, as an objective measurement, might help assess cognitive impairment in children with OSA.

Diagnostic accuracy of level IV portable sleep monitors versus polysomnography for pediatric obstructive sleep apnea: a systematic review and meta-analysis

BACKGROUND

Obstructive sleep apnea (OSA) is one of the common sleep-related breathing disorders in children. However, polysomnography (PSG) is an expensive and labor-intensive diagnostic modality that may not always be feasible, especially in low-income countries or in non-tertiary hospitals. Portable monitors (PMs), a new approach for OSA diagnosis, have become more widely used with lower intolerance and cost in recent years. We aimed to analyze the diagnostic performance of Level IV PMs compared with PSG for the diagnosis of pediatric OSA.

METHODS

PubMed and Embase databases were searched for studies published in English up to December 31, 2020 evaluating the diagnostic accuracy of Level IV PMs against the apnea-hypopnea index (AHI) measured using overnight in-laboratory polysomnography (PSG) in children and adolescents. A random-effects bivariate model was used to estimate the summary sensitivity and specificity of oximetry-based statistical classifiers. A qualitative evaluation of studies was performed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) rating.

RESULTS

In total, 20 studies involving 7062 participants were included in this systematic review. Among these articles, seven studies (oximetry based on new mathematical classifiers) involving 5098 individuals satisfied the criteria for quantitative synthesis. Compared with AHI evaluation measured by PSG, different PM systems achieved diagnostic accuracy with variable degrees of success. A meta-analysis showed a pooled sensitivity of 74% (95% confidence interval [CI]: 66-80%) and pooled specificity of 90% (95% CI: 85-94%). The area under the summary receiver operating characteristic (SROC) curve was 0.89 (95% CI: 0.86-0.92).

CONCLUSION

This study showed the potential of Level IV PMs for screening pediatric OSA patients. Oximetry based on new mathematical classifiers may provide a simple and effective alternative to PSG in the diagnosis of pediatric OSA especially in the context of appropriate clinical evaluation.

Validity and reliability of the Thai version of the pediatric obstructive sleep apnea screening tool

OBJECTIVE

Obstructive sleep apnea (OSA) is highly prevalent in children and requires an expensive and relatively unavailable sleep study for diagnosis. This study was undertaken to translate the previously validated pediatric OSA screening tool (POSAST) to the Thai language and assess its accuracy and test-retest reliability in at-risk symptomatic children.

STUDY DESIGN

Prospective cross-sectional cohort study.

METHODS

Pediatric patients clinically referred for suspected OSA who underwent overnight polysomnography (PSG) were recruited, and caregivers completed the Thai version of the POSAST. The same questionnaire was completed again after 2-4 weeks. The reliability of the questionnaire was determined by internal consistency and test-retest reliability. The validity of the questionnaire was assessed by constructing receiver operating characteristic (ROC) curves to identify the equation-derived score and total additive score cutoff points that identify high risk for moderate and severe OSA (AHI of ≥ 5 events/h).

RESULTS

One hundred and ten subjects completed the study. The mean age was 8.4 ± 2.9 years. The mean apnea-hypopnea index (AHI) was 10.9 ± 11.9 events/h. Test-retest reliability (Pearson correlation coefficient = 0.96, p < .001) and internal consistency between each question (Cronbach's alpha coefficient = 0.82, p < .001) were excellent. An equation-derived score cut-off of 1.9 yielded 78.4% sensitivity, 50.0% specificity, 76.3% positive predictive value (PPV), and 52.9% negative predictive value (NPV), while a total additive score cut-off of 8 corresponded to 81.1% sensitivity, 52.8% specificity, 77.9% PPV, and 57.6% NPV for diagnosing moderate and severe OSA (AHI ≥ 5 events/h).

CONCLUSION

The internal consistency and reproducibility of the Thai version of the POSAST are satisfactory, display acceptable validity, and the instrument can be used for screening symptomatic Thai children for OSA.

Pediatric obstructive sleep apnea revisited: Perioperative considerations for the pediatric Anesthesiologist

Pediatric obstructive sleep apnea presents in up to 7% of children and represents a constellation from nasal turbulence to cessation in gas exchange. There are numerous end organ sequelae including neurocognitive morbidity associated with persistent OSA. Adenotonsillectomy (AT), the first line therapy for pediatric OSA, has not been demonstrated to reduce all end organ morbidity, specifically neurological and behavioral morbidity. Furthermore, certain at-risk populations are at higher risk from neurocognitive morbidity. Precise knowledge and perioperative planning is required to ensure optimal evidence-based practices in children with OSA. This comprehensive review covers the seminal perioperative implications of OSA, including preoperative polysomnography, pharmacotherapeutics, and postoperative risk stratification.

Polysomnographic Outcomes After Observation for Mild Obstructive Sleep Apnea in Children Younger Than 3 Years

OBJECTIVE

Mild obstructive sleep apnea (OSA), particularly in young children, is often treated with observation. However, there is little evidence regarding the outcomes with this approach. Our aim was to assess the impact of observation on sleep for children aged <3 years with mild OSA.

STUDY DESIGN

Case-control study.

SETTING

Pediatric tertiary care center.

METHODS

We reviewed cases of children (<3 years old) diagnosed with mild OSA (obstructive apnea-hypopnea index, 1-5 events/h) who were treated with observation between 2012 and 2017 and had at least 2 polysomnograms performed 3 to 12 months apart. Demographic data and comorbid diagnoses were collected.

RESULTS

Twenty-six children met inclusion criteria; their median age was 7.2 months (95% CI, 1.2-22.8). Nine (35%) were female and 24 (92%) were White. Their median body mass index percentile was 39 (95% CI, 1-76). Comorbidities included cardiac disease (42.3%), laryngomalacia (42.3%), allergies (34.6%), reactive airway disease (23.1%), and prematurity (7.7%). The obstructive apnea-hypopnea index significantly decreased from 2.7 events/h (95% CI, 1-4.5) to 1.3 (95% CI, 0-4.5; P = .013). There was no significant improvement in median saturation nadir (baseline, 86%; P = .76) or median time with end-tidal carbon dioxide >50 mm Hg (baseline, 0 minutes; P = .34). OSA resolved in 8 patients (31%) and worsened in 1 (3.8%). Only race was a significant predictor of resolution per regression analysis; however, only 2 non-White children were included.

CONCLUSION

In our cohort, resolution of mild OSA occurred in 31% of patients treated with 3 to 12 months of observation. The presence of laryngomalacia, asthma, and allergies did not affect resolution. Larger studies are needed to better identify factors (including race) associated with persistent OSA and optimal timing of intervention for these children.

LEVEL OF EVIDENCE

4.

The relationship between inflammation and neurocognitive dysfunction in obstructive sleep apnea syndrome

Obstructive sleep apnea syndrome (OSAS), a state of sleep disorder, is characterized by repetitive apnea, chronic hypoxia, oxygen desaturation, and hypercapnia. Previous studies have revealed that intermittent hypoxia (IH) conditions in OSAS patients elicited neuron injury (especially in the hippocampus and cortex), leading to cognitive dysfunction, a significant and extraordinary complication of OSAS patients. The repeated courses of airway collapse and obstruction in OSAS patients resulted in apnea and arousal during sleep, leading to IH and excessive daytime sleepiness (EDS) and subsequently contributing to the development of inflammation. IH-mediated inflammation could further trigger various types of cognitive dysfunction. Many researchers have found that, besides continuous positive airway pressure (CPAP) treatment and surgery, anti-inflammatory substances might alleviate IH-induced neurocognitive dysfunction. Clarifying the role of inflammation in IH-mediated cognitive impairment is crucial for potentially valuable therapies and future research in the related domain. The objective of this article was to critically review the relationship between inflammation and cognitive deficits in OSAS.

Diagnostic meta-analysis of the Pediatric Sleep Questionnaire, OSA-18, and pulse oximetry in detecting pediatric obstructive sleep apnea syndrome

The aim of this meta-analysis was to compare the pooled sensitivity and specificity of the Pediatric Sleep Questionnaire (PSQ), Obstructive Sleep Apnea Questionnaire (OSA-18), and pulse oximetry (PO) according to OSAS severity. Three electronic databases were searched for studies evaluating sensitivity and specificity of the three tools against the apnea-hypopnea index measured using overnight in-laboratory or in-home polysomnography in children and adolescents from inception until January 11, 2020. A random-effects bivariate model was used to estimate the summary sensitivity and specificity of the tools. We identified 39 studies involving 6131 clinical and community children (aged 2.9-16.7 y). The PSQ exhibited the highest sensitivity (74%) for detecting symptoms of mild pediatric OSAS. The PSQ and PO had comparable sensitivity in screening moderate and severe pediatric OSAS (0.82 and 0.89 vs 0.83 and 0.83, respectively). PO yielded superior specificity in detecting mild, moderate, and severe pediatric OSAS (86%, 75%, and 83%, respectively) than did the PSQ and OSA-18 (all p < 0.05). Age, percentage of girls, index test criteria, methodology quality, and sample size significantly moderated sensitivity and specificity. For early detection of pediatric OSAS, the combined use of PSQ and PO is recommended when polysomnography is not available. PROSPERO REGISTRATION NUMBER: CRD42018090571.

Enhancing Executive Control: Attention to Balance, Breath, and the Speed Versus Accuracy Tradeoff

Malleability of executive control and its enhancement through yoga training is unclear. In Study 1, participants (yoga group; n = 27, mean = 23.27 years) were tested on executive control tasks pre- and post-8 weeks of yoga training. The training focused on attention to postural control during yoga asanas and respiratory control during pranayama-breathing (30 min each of postural and breath control training, biweekly). Yoga training was assessed via performance ratings as to how well a posture was executed and by examining errors that reflected inattention/failures in postural and breath control. We also explored whether attentional demands on motor and respiratory control were associated with three components of executive control (working memory, cognitive flexibility, and inhibition) during nine executive control tasks. Partial correlation results revealed that the three components of executive control might be differentially impacted by postural and breath control and selectively associated with either speed or accuracy (except for cognitive flexibility). Attentional demands influenced the link between postural, breath, and cognitive control. In Study 2, comparisons between a yoga group and a gender-matched control group (control group; n = 27, mean = 23.33 years) pointed toward higher working memory accuracy and a better speed-accuracy tradeoff in inhibitory control in the yoga group. A ceiling-practice effect was addressed by examining yoga practice learning (i.e., practice-induced change in postural and breath control reflected in ratings and errors) on executive control performance across two sets of tasks: repeatedly tested (pre- and post-8 weeks) and non-repeatedly tested (post-8 weeks). Attention to motor and respiratory control during yoga might be considered as a potential mechanism through which specific components of executive control in young adults might be enhanced potentially via altering of speed-accuracy tradeoff.

Related biomarkers of neurocognitive impairment in children with obstructive sleep apnea

OBJECTIVES

Different experiment approaches have demonstrated that children with obstructive sleep apnea (OSA) exhibit neurocognitive and behavioral deficits. This review summarized the potential biomarkers of OSA-associated neurocognitive impairment in children.

METHODS

A scoping review of studies on children with OSA that evaluated the potential value of different markers in identifying neurocognitive impairment was undertaken. Additionally, the biomarkers were categorized according to the different research methods, including brain imaging studies, serological indicators and urine markers.

RESULTS

Majority of the studies that evaluated blood biomarkers, plasma insulin growth factor-1 (IGF-1) and Alzheimer's disease (AD)-related biomarkers appeared to exhibit a favorable profile, and could discriminate between OSA children with or without neurocognitive impairments. Brain imaging studies and urinary neurotransmitters could also be helpful for screening OSA cognitive morbidity in children.

CONCLUSION

Due to limited research methods available in children, the cognitive susceptibility of children with OSA has been rarely studied. The main reason for this may be the limited research methods in children. Numerous study populations of children and complex psychological tests are required, which involve major labor and costs.Multi-center prospective studies are needed to identify suitable biomarkers for the timely prediction and effective intervention to prevent neurocognitive impairment in children with OSA and to explore further opportunities in this arena.

Cognitive and Behavioral Consequences of Sleep Disordered Breathing in Children

There is now a plethora of evidence that children with sleep disordered breathing (SDB) show deficits in neurocognitive performance, behavioral impairments, and school performance. The following review will focus on the neurobehavioral impacts of SDB, pediatric sleep investigation challenges, potential mechanisms of behavioral and cognitive deficits in children with SDB, and the impact of SDB treatment.

How do we recognize the child with OSAS?

Obstructive sleep-disordered breathing includes a spectrum of clinical entities with variable severity ranging from primary snoring to obstructive sleep apnea syndrome (OSAS). The clinical suspicion for OSAS is most often raised by parental report of specific symptoms and/or abnormalities identified by the physical examination which predispose to upper airway obstruction (e.g., adenotonsillar hypertrophy, obesity, craniofacial abnormalities, neuromuscular disorders). Symptoms and signs of OSAS are classified into those directly related to the intermittent pharyngeal airway obstruction (e.g., parental report of snoring, apneic events) and into morbidity resulting from the upper airway obstruction (e.g., increased daytime sleepiness, hyperactivity, poor school performance, inadequate somatic growth rate or enuresis). History of premature birth and a family history of OSAS as well as obesity and African American ethnicity are associated with increased risk of sleep-disordered breathing in childhood. Polysomnography is the gold standard method for the diagnosis of OSAS but may not be always feasible, especially in low-income countries or non-tertiary hospitals. Nocturnal oximetry and/or sleep questionnaires may be used to identify the child at high risk of OSAS when polysomnography is not an option. Endoscopy and MRI of the upper airway may help to identify the level(s) of upper airway obstruction and to evaluate the dynamic mechanics of the upper airway, especially in children with combined abnormalities. Pediatr Pulmonol. 2017;52:260-271. © 2016 Wiley Periodicals, Inc.

Anxiety sensitivity and working memory capacity: Risk factors and targets for health behavior promotion

Understanding the nature and influence of specific risk profiles is increasingly important for health behavior promotion. The purpose of this article is to document the value of two factors-anxiety sensitivity (AS) and working memory capacity (WMC)-for enhancing risk for the initiation and/or maintenance of a range of negative health behaviors. AS is a distress-related risk factor that potentiates avoidance/coping motivations for negative health behaviors. Stress provides the conditions for negative somatic and affective states, and AS amplifies the aversiveness of these experiences and correspondingly hinders adaptive functioning. In contrast, low WMC is hypothesized to exert its effect by decreasing the capacity to filter out current temptations, attenuating a focus on longer-term goals and impairing the application of relevant coping skills at times of stress. In this review, we provide conceptual models for the separate roles of high AS and low WMC in negative health behaviors, review the influence of these factors on specific health behavior exemplars (eating behaviors/obesity, physical activity, smoking, alcohol use, and sleep promotion), provide preliminary evidence for their value as independent treatment targets for health-behavior promotion, and encourage specific research directions in relation to these variables.

Disorders of Sleep and Ventilatory Control in Prader-Willi Syndrome

Prader-Willi syndrome (PWS) is an imprinted genetic disorder conferred by loss of paternal gene expression from chromosome 15q11.2-q13. Individuals with PWS have impairments in ventilatory control and are predisposed toward sleep disordered breathing due to a combination of characteristic craniofacial features, obesity, hypotonia, and hypothalamic dysfunction. Children with PWS progress from failure to thrive during infancy to hyperphagia and morbid obesity during later childhood and onward. Similarly, the phenotype of sleep disordered breathing in PWS patients also evolves over time from predominantly central sleep apnea in infants to obstructive sleep apnea (OSA) in older children. Behavioral difficulties are common and may make establishing effective therapy with continuous positive airway pressure (CPAP) more challenging when OSA persists after adenotonsillectomy. Excessive daytime sleepiness (EDS) is also common in patients with PWS and may continue after OSA is effectively treated. We describe here the characteristic ventilatory control deficits, sleep disordered breathing, and excessive daytime sleepiness seen in individuals with PWS. We review respiratory issues that may contribute to sudden death events in PWS patients during sleep and wakefulness. We also discuss therapeutic options for treating sleep disordered breathing including adenotonsillectomy, weight loss, and CPAP. Lastly, we discuss the benefits and safety considerations related to growth hormone therapy.

Mild obstructive sleep apnoea: clinical relevance and approaches to management

Obstructive sleep apnoea is highly prevalent in the general population worldwide, especially in its mild form. Clinical manifestations correlate poorly with disease severity measured by the apnoea-hypopnoea index (AHI), which complicates diagnosis. Full polysomnography might be more appropriate to assess suspected mild cases because limited ambulatory diagnostic systems are least accurate in mild disease. Treatment options in mild obstructive sleep apnoea include continuous positive airway pressure (CPAP) and oral appliance therapy, in addition to positional therapy and weight reduction when appropriate. The superior efficacy of CPAP in reducing AHI is offset by greater tolerance of oral appliances, especially in mild disease. Although severe obstructive sleep apnoea is associated with adverse health consequences, including cardiometabolic comorbidities, the association with mild disease is unclear, and reports differ regarding the clinical relevance of mild obstructive sleep apnoea. Improved diagnostic techniques and evidence-based approaches to management in mild obstructive sleep apnoea require further research.

Transoral Robotic Surgery for Obstructive Sleep Apnea: A Systematic Review and Meta-Analysis

OBJECTIVE

To perform a systematic review of the international biomedical literature evaluating the effectiveness, complications, and safety of transoral robotic surgery (TORS) for the treatment of obstructive sleep apnea (OSA).

DATA SOURCES

PubMed/MEDLINE, Embase, and EMB Reviews databases were searched up to November 27, 2015.

REVIEW METHODS

Two authors systematically and independently searched for articles on TORS for the treatment of OSA in adults that reported either outcomes for the apnea-hypopnea index (AHI), lowest oxygen saturation percentage (LSAT) or changes in the Epworth Sleepiness Scale (ESS), and/or rates and types of complications associated with the operation.

RESULTS

In total, 181 records were identified and 16 articles met inclusion criteria. Transoral robotic surgery was almost always combined with other sleep surgery procedures. The summary estimate of the decrease in AHI using TORS as part of a multilevel surgical approach was 24.0 (95% confidence interval [CI], 22.1-25.8; P < .001, I(2) = 99%). The summary estimate of a decrease in ESS score was 7.2 (95% CI, 6.6-7.7; P < .001, I(2) = 99%) and of the overall surgical "success" (defined as AHI <20 and 50% reduction) was 48.2% (95% CI, 38.8%-57.7%; P < .001, I(2) = 99%). Three large studies reported on their total complication rates with an average of 22.3% (range, 20.5%-24.7%).

CONCLUSIONS

The initial results for the use of TORS as part of a multilevel surgical approach for OSA are promising for select patients. However, the cost and morbidity may be greater than with other techniques offsetting its advantages in visualization and precision. More prospective studies are needed to determine the optimal role of this tool.

Cognitive deficits in adults with obstructive sleep apnea compared to children and adolescents

Obstructive sleep apnea (OSA) can negatively affect the patient's physical and psychological functioning, as well as their quality of life. A major consequence of OSA is impaired cognitive functioning. Indeed, several studies have shown that OSA mainly leads to deficits in executive functions, attention, and memory. As OSA can present in all age groups, these associated cognitive deficits have been observed in adults, as well as in children and adolescents. However, these cognitive deficits may have a different clinical picture in young patients compared to adults. In this review, we analyze the most affected cognitive domains in adults and children/adolescents with OSA, as evaluated by neuropsychological and neuroimaging studies. We found that deficits in working memory, attention, or executive functions cognitive domains are found in both adults and children with OSA. However, children with OSA also show changes in behavior and phonological processing necessary for proper development. Moreover, we examine the possible OSA treatments in children and adults that can have a positive influence on cognition, and therefore, improve patients' general functioning and quality of life.