Daytime sleepiness associated with poor sustained attention in middle and late adulthood

Resting-state electroencephalography (EEG) microstates of healthy individuals following mild sleep deprivation

Mild sleep deprivation is widespread in many societies worldwide. Electroencephalography (EEG) microstate analysis provides information on spatial and temporal characteristics of resting brain network, serving as an indicator of neurophysiological activities at rest. This study seeks to investigate potential neural markers in EEG following mild sleep deprivation of a single night using EEG microstate analysis. Six-minute resting EEG was conducted on thirty healthy adults within 6 hours of waking in the morning and after at least 18 h of sleep deprivation. Translated and validated Malay language Karolinska Sleepiness Scale was used to assess the participants' degree of sleepiness. Microstate characteristics analysis was conducted on the final 24 subjects based on four standard microstate maps. Microstate C shows a significant increase in mean duration, coverage and occurrence, while microstate D has significantly higher occurrence after sleep deprivation. This study demonstrates notable changes in resting state EEG microstates following mild sleep deprivation. Present findings deepen our understanding of the brain's spatiotemporal dynamics under this condition and suggest the potential utility of neural markers in this domain as components of composite markers for sleep deprivation.

Hilaire MA, Arrona-Palacios A, Czeisler CA, Duffy JF. Time of Day and Sleep Deprivation Effects on Risky Decision Making

Previous research has revealed that daily variations in human neurobehavioral functions are driven in part by the endogenous circadian system. The objective of this study was to explore whether there exists a circadian influence on performance regarding a risky decision-making task and to determine whether the performance changes with sleep deprivation (SD). Thirteen participants underwent a 39 h constant routine (CR) protocol, during which they remained awake in constant conditions and performed the BART (balloon analogue risk task) every two hours. The mean pumps (gains) (p < 0.001) and balloons popped (losses) (p = 0.003) exhibited variation during the CR. The reaction time (RT) also showed significant variation across the CR (p < 0.001), with slower mean RTs in the morning hours following SD. A greater risk propensity was observed around midday before SD and a lower risk propensity after 29.5 h of being awake. The sensitivity to punishment varied during the CR, but did not follow a predictable trend. Further research using real monetary incentives and neurophysiological measures is warranted to elucidate these findings.

Factors affecting the psychomotor vigilance of nurses working night shift

BACKGROUND

Shifts and long working hours decrease the psychomotor vigilance of healthcare workers especially when working night shifts. Working night shifts adversely affects nurses' health and impacts patient safety.

AIM

The purpose of this study is to identify factors affecting the psychomotor vigilance of nurses working night shift.

METHODS

This descriptive cross-sectional study was carried out with 83 nurses who were working in a private hospital in Istanbul and voluntarily participated in this study between April 25 and May 30, 2022. Data were collected using "Descriptive Characteristics Form," "Psychomotor Vigilance Task," "Pittsburgh Sleep Quality Index," and "Epworth Sleepiness Scale." The "STROBE checklist" for cross-sectional studies was utilized in order to report the findings of the study.

RESULTS

When time-dependent variation of the nurses' psychomotor vigilance task performances on the night shift was examined, it was observed that the nurses' mean reaction time and number of lapses increased at the end of the night shift. Age, smoking, physical activity, daily water consumption, daytime sleepiness, and sleep quality were found as the factors affecting nurses' psychomotor vigilance.

CONCLUSION

The psychomotor vigilance task performances of nurses working night shift are affected by age and a variety of behavioral factors.

IMPLICATIONS FOR NURSING AND HEALTH POLICY

Suggestions for nursing policy include the implementation of workplace health promotion programs in order to increase the attention level of nurses in order to ensure employee and patient health and safety and create a healthy working environment.

Targeting Slow Wave Sleep Deficiency in Late-Life Depression: A Case Series With Propofol

Slow wave sleep (SWS), characterized by large electroencephalographic oscillations, facilitates crucial physiologic processes that maintain synaptic plasticity and overall brain health. Deficiency in older adults is associated with depression and cognitive dysfunction, such that enhancing sleep slow waves has emerged as a promising target for novel therapies. Enhancement of SWS has been noted after infusions of propofol, a commonly used anesthetic that induces electroencephalographic patterns resembling non-rapid eye movement sleep. This paper 1) reviews the scientific premise underlying the hypothesis that sleep slow waves are a novel therapeutic target for improving cognitive and psychiatric outcomes in older adults, and 2) presents a case series of two patients with late-life depression who each received two propofol infusions. One participant, a 71-year-old woman, had a mean of 2.8 minutes of evening SWS prior to infusions (0.7% of total sleep time). SWS increased on the night after each infusion, to 12.5 minutes (5.3% of total sleep time) and 24 minutes (10.6% of total sleep time), respectively. Her depression symptoms improved, reflected by a reduction in her Montgomery-Asberg Depression Rating Scale (MADRS) score from 26 to 7. In contrast, the other participant, a 77-year-old man, exhibited no SWS at baseline and only modest enhancement after the second infusion (3 minutes, 1.3% of total sleep time). His MADRS score increased from 13 to 19, indicating a lack of improvement in his depression. These cases provide proof-of-concept that propofol can enhance SWS and improve depression for some individuals, motivating an ongoing clinical trial (ClinicalTrials.gov NCT04680910).

Moderate-to-high risk of obstructive sleep apnea with excessive daytime sleepiness is associated with postoperative neurocognitive disorders: a prospective one-year follow-up cohort study

Background

Few studies found that obstructive sleep apnea (OSA) may be related to postoperative neurocognitive disorders (PND) including postoperative delirium (POD) and cognitive decline (POCD) in the early postoperative period. However, the results are controversial and need further verification, and no research has explored the effect of OSA on the incidence of PND during the 1-year follow-up periods. Furthermore, OSA patients with excessive daytime sleepiness (EDS) as a severe phenotype have more significant neurocognitive impairments, but the relationship between OSA with EDS and PND within 1 year after surgery has not been studied.

Objectives

To explore the effect of moderate-to-high risk of OSA and the moderate-to-high risk of OSA with EDS on PND within 1 year after surgery.

Methods

In this prospective cohort study, including 227 older patients, moderate-to-high risk of OSA (using STOP-BANG), subjective EDS (using Epworth Sleepiness Scale), and objective EDS (using Actigraphy) were selected as exposures. Key outcomes included POD during hospitalization (using Confusion Assessment Method-Severity), POCD at discharge, 1-month and 1-year after surgery (using Mini-Mental State Examination and Telephone Interview for Cognitive Status-40). We applied multiple logistic regression models to estimate the effect of moderate-to-high risk of OSA and moderate-to-high risk of OSA with EDS on PND.

Results

In the multivariate analysis, moderate-to-high risk of OSA was not associated with POD during hospitalization and POCD at discharge, 1-month, and 1-year after surgery (p > 0.05). However, the moderate-to-high risk of OSA with subjective EDS was related to POCD at discharge compared to the moderate-to-high risk of OSA or normal group (no moderate-to-high risk of OSA and no EDS) (p < 0.05). In addition, moderate-to-high risk of OSA with objective EDS was associated with POCD at discharge, 1-month, and 1-year postoperatively compared to the moderate-to-high risk of OSA or normal group (p < 0.05).

Conclusion

Moderate-to-high risk of OSA with EDS, not moderate-to-high risk of OSA alone, was a clinically helpful predictor for POCD within 1-year after surgery and should be routinely assessed before surgery.

The beneficial effects of integrating a personalized telephone-delivered component into digital cognitive behavioral therapy for insomnia in a large, hospital-based population

OBJECTIVES

Although digital cognitive behavior therapy for insomnia (D-CBTI) has been shown to be a viable treatment for insomnia, lacking flexibility of response and direct practitioner-to-patient contact and comfort potentially limited its efficacy. Integrating personalized telephone sessions into D-CBTI may overcome these obstacles, potentially providing additional clinical benefit to chronic insomnia patients. We evaluate the clinical effectiveness of telephone plus D-CBTI (TD-CBTI) versus D-CBTI alone.

METHODS

Insomnia patients were selected consecutively from the Sleep Medicine Center, West China Hospital from March 2020 to February 2021. Insomnia was defined by Diagnostic and Statistical Manual for Mental Disorders criteria with symptoms lasting ≥3 months. Standard D-CBTI was administered through the APP "SUMIAN," which provided fully automated, interactive and standard CBTI over six weekly treatments. TD-CBTI added weekly 10-15 min personalized telephone-based sessions to D-CBTI.

RESULTS

One hundred and seven patients received D-CBTI and 465 patients received TD-CBTI. Pre-to posttreatment differences of ISI and most sleep diary reported sleep indexes were comparable between groups. However, TD-CBTI patients showed significantly increased odds of SE based remission (167%, OR = 2.67, 95% CI 1.34-5.23), and significantly increased odds of reduction of sleep medications (352%, OR = 4.52, 95% CI 1.27-10.05).

CONCLUSIONS

This study demonstrates that integration of personalized telephone sessions into D-CBTI treatment, provides increased clinical benefit to insomnia patients, particularly for successful discontinuation of sleep medications.

EEG-based drowsiness analysis using OpenBCI and deep learning approaches to establish driving safety

Drowsiness is the inactivated state of the brain and observed during the transition from awaken state to sleepy state. This inactive state diminishes an individual’s attention and leads to accidents during professional or personal activities. The prediction of this inactive (drowsiness) state using AI plays a substantial role in the avoidance of accidents. The advancements in the field of Artificial Intelligence and Neuroscience approaches are used for the prediction of this inactive drowsy state. In order to prevent these devastating accidents, the state of drowsiness of the driver has to be be monitored. Electroencephalogram (EEG) is a predominant tool adopted to examine various states of the brain effectually. It is generally known as Brain-Computer Interface System. The EEG channels are used for predicting the inactive state while implementing the real-time applications. However, the researchers face various challenges during execution based on the classification and channel selection process. This research concentrates on modelling and efficient drowsiness prediction methods and intends to bridge the gap encountered in the existing approaches. A novel stacked Long Short-Term Memory(s - LSTM) with Deep Fully Connected- Convolutional Neural Network (DFC - CNN) is used to learn and memorize the long-term feature dependencies and attains essential information based on time-series prediction. Single and multi-channel EEG data is considered to measure the statistical characteristics of available EEG signals. The online available OpenBCI sleep analysis data is used for performing the experimentation, and run in GoogleColab environment. The proposed s - LSTM model provides a better trade-off compared to existing approaches. The model generalization is improved with the validation of combined feature subjects. Here, metrics like prediction accuracy, RMSE, false positives, scaling coefficients related to false positives are measured to show the significance of the model.

The EEG correlates and dangerous behavioral consequences of drowsy driving after a single night of mild sleep deprivation

OBJECTIVE

Here, we investigated the behavioral, cognitive, and electrophysiological impact of mild, acute sleep loss via simultaneously recorded behavioral and electrophysiological measures of vigilance during a "real-world", simulated driving task.

METHODS

Participants (N = 34) visited the lab for two testing days where their brain activity and vigilance were simultaneously recorded during a driving simulator task. The driving task lasted approximately 70 mins and consisted of tailgating the lead car at high speed, which braked randomly, requiring participants to react quickly to avoid crashing. The night before testing, participants either slept from 12am-9am (Normally Rested), or 1am-6am (Sleep Restriction).

RESULTS

After a single night of mild sleep restriction, sleepiness was increased, participants took longer to brake, missed more braking events, and crashed more often. Brain activity showed more intense alpha burst activity and significant changes in EEG spectral power frequencies related to arousal (e.g., delta, theta, alpha). Importantly, increases in amplitude and number of alpha bursts predicted delays in reaction time when braking.

CONCLUSIONS

The findings of this study suggest that a single night of mild sleep loss has significant, negative consequences on driving performance and vigilance, and a clear impact on the physiology of the brain in ways that reflect reduced arousal.

SIGNIFICANCE

Understanding neural and cognitive changes associated with sleep loss may lead to important advancements in identifying and preventing potentially dangerous sleep-related lapses in vigilance.

Severity of Daytime Sleepiness and Parkinsonian-Like Symptoms in Korean Adults Aged 50-64 Years

Background and Purpose

While excessive daytime sleepiness can predate Parkinson’s disease in late-life, its association with parkinsonian-like (P-L) symptoms in middle age are unknown. Since neurodegeneration can appear decades before a diagnosis of Parkinson’s disease, identifying clinical features associated with this early progression is important. The purpose of this study was to determine the association of daytime sleepiness with P-L symptoms in a population-based sample of middle-aged Korean adults.

Methods

During 2013 and 2014, daytime sleepiness and P-L symptoms were assessed in 2,063 males and females aged 50–64 years who were participating in the Korean Genome and Epidemiology Study. The severity of daytime sleepiness was quantified by the score on the Epworth Sleepiness Scale (ESS). Self-reported P-L symptoms included nine motor disorders commonly associated with Parkinson’s disease. Participants with parkinsonism and related conditions are excluded.

Results

The prevalence of excessive daytime sleepiness (ESS score >10) was 7.0%. The frequencies of P-L symptoms ranged from 0.5% (for “trouble buttoning buttons”) to 18.4% (for “handwriting smaller than it once was”). After adjustment for covariates and multiple testing, the relative odds of P-L symptoms comparing the 80th and 20th percentiles of ESS scores was 1.6 (p=0.001) for “voice is softer than it once was,” 2.1 (p<0.001) for “balance when walking is poor,” and 1.5 (p=0.002) for “loss of facial expression.” The prevalence of excessive daytime sleepiness increased from 6.3% to 19.8% when the number of symptoms increased from zero to three (p=0.004).

Conclusions

In Korean adults aged 50–64 years, daytime sleepiness is significantly associated with P-L symptoms. Whether coexisting daytime sleepiness and P-L symptoms predate extrapyramidal and other impairments in later life warrants further investigation.

Associations between Sleep and Work-Related Cognitive and Emotional Functioning in Police Employees

AIM

We aimed to examine the cross-sectional and longitudinal associations between sleep and work-related impaired cognitive and emotional functioning in police employees.

METHODS

This study included 410 participants (52% men) employed in a police district in Norway at baseline, of which 50% also participated in the study at 6 months later follow-up. The questionnaires included items measuring work schedule, sleep length, insomnia, as well as impaired cognitive and emotional functioning at work.

RESULTS

The results showed that insomnia was related to impaired work-related emotional functioning measured at baseline, and to impaired cognitive functioning measured at both baseline and follow-up. Sleep length and rotating shift work were not associated with future decline in cognitive or emotional functioning.

CONCLUSION

Our study indicates that the relationship between insomnia and emotional functioning at work may be transient, whereas insomnia can be related to both immediate and future impaired cognitive functioning. Replication of the findings in larger samples is advised. The findings call for an emphasis on the prevention and treatment of sleep problems among police employees as a mean of maintaining and improving cognitive and emotional functioning at work, and thereby reducing the risk for impaired performance and negative health and safety outcomes.

Fidelity of Information Processing on a Psychomotor Vigilance Task Predicts Changes in Self-Reported Sleepiness Ratings

INTRODUCTION

Daytime sleepiness is a common problem. Although sleepiness is primarily assessed at the self-report unit of analysis, factors that contribute to an individual's experience and report of sleepiness remain poorly understood. While sleepiness is known to impact vigilance performance, the impact of vigilance performance on sleepiness reports is less well understood. We aimed to explore how performance on a psychomotor vigilance task (PVT) relates to changes in self-reported sleepiness in a rested condition.

METHODS

Participants were 66 adults (Mdn=23, range 18-49 years old), 47% female, 88% white, with a wide range of insomnia symptoms. Participants rated their sleepiness on a scale from 1 (not sleepy) to 10 (extremely sleepy) at the start (pre) and the end (post) of a 10-minute computerized PVT. Ordinal regression determined whether mean reciprocal reaction time, a measure of overall performance, or the log-transformed signal-to-noise ratio (LSNR), a measure of fidelity of information processing, predicted post-sleepiness, adjusting for pre-sleepiness, insomnia, and potential confounds.

RESULTS

Lower LSNR predicted greater change in sleepiness (pre-to-post PVT) and higher post-sleepiness even after adjusting for pre-sleepiness, mean reciprocal reaction time, insomnia, and other potential confounds (p<0.05).

DISCUSSION

When adjusting for insomnia symptoms and potential confounds, participants with lower fidelity of information processing reported higher sleepiness than they had reported at the start of the PVT. Possible mechanisms and explanations are discussed in relation to a 3-factor model of sleep-wake states. This line of research may contribute to innovative approaches to assessing and treating sleepiness.

Increased nocturnal arterial pulsation frequencies of obstructive sleep apnoea patients is associated with an increased number of lapses in a psychomotor vigilance task

Objectives

Besides hypoxaemia severity, heart rate variability has been linked to cognitive decline in obstructive sleep apnoea (OSA) patients. Thus, our aim was to examine whether the frequency domain features of a nocturnal photoplethysmogram (PPG) can be linked to poor performance in the psychomotor vigilance task (PVT).

Methods

PPG signals from 567 suspected OSA patients, extracted from Type 1 diagnostic polysomnography, and corresponding results of PVT were retrospectively examined. The frequency content of complete PPGs was determined, and analyses were conducted separately for men (n=327) and women (n=240). Patients were grouped into PVT performance quartiles based on the number of lapses (reaction times ≥500 ms) and within-test variation in reaction times. The best-performing (Q1) and worst-performing (Q4) quartiles were compared due the lack of clinical thresholds in PVT.

Results

We found that the increase in arterial pulsation frequency (APF) in both men and women was associated with a higher number of lapses. Higher APF was also associated with higher within-test variation in men, but not in women. Median APF (β=0.27, p=0.01), time spent under 90% saturation (β=0.05, p<0.01), female sex (β=1.29, p<0.01), older age (β=0.03, p<0.01) and subjective sleepiness (β=0.07, p<0.01) were significant predictors of belonging to Q4 based on lapses. Only female sex (β=0.75, p<0.01) and depression (β=0.91, p<0.02) were significant predictors of belonging to Q4 based on the within-test variation.

Conclusions

In conclusion, increased APF in PPG provides a possible polysomnography indicator for deteriorated vigilance especially in male OSA patients. This finding highlights the connection between cardiorespiratory regulation, vigilance and OSA. However, our results indicate substantial sex-dependent differences that warrant further prospective studies.

EEG and behavioural correlates of mild sleep deprivation and vigilance

OBJECTIVE

The current study investigated the behavioral, cognitive, and electrophysiological impact of mild (only a few hours) and acute (one night) sleep loss via simultaneously recorded behavioural and physiological measures of vigilance.

METHODS

Participants (N = 23) came into the lab for two testing days where their brain activity and vigilance were recorded and assessed. The night before the testing session, participants either slept from 12am to 9am (Normally Rested), or from 1am to 6am (Sleep Restriction).

RESULTS

Vigilance was reduced and sleepiness was increased in the Sleep Restricted vs. Normally Rested condition, and this was exacerbated over the course of performing the vigilance task. As well, sleep restriction resulted in more intense alpha bursts. Lastly, EEG spectral power differed in Sleep Restricted vs. Normally Rested conditions as sleep onset progressed, particularly for frequencies reflecting arousal (e.g., delta, alpha, beta).

CONCLUSIONS

The findings of this study suggest that only one night of mild sleep loss significantly increases sleepiness and, importantly, reduces vigilance. In addition, this sleep loss has a clear impact on the physiology of the brain in ways that reflect reduced arousal.

SIGNIFICANCE

Understanding the neural correlates and cognitive processes associated with loss of sleep may lead to important advancements in identifying and preventing deleterious or potentially dangerous, sleep-related lapses in vigilance.

The Relationship between Performance of Attention Task and Suicidal Ideation in Korean Patients with Mood Disorders

OBJECTIVE

We examined the performance of attention tests related to suicidal ideation in mood disorder patients and to explain the difference of attention test performance in relation to suicidal ideation after controlling clinical and psychological variables of mood disorder patients.

METHODS

Seventy-three in- and outpatients with major depressive disorder (n=41) or bipolar disorder (n=32) completed a self-rating questionnaire assessing socio-demographic characteristics, and clinical and psychological variables. Comprehensive Attention Test (CAT) also was conducted.

RESULTS

Thirty-three patients were the high-suicidal ideation (SI) group, and forty patients were the low-SI group. The errors of commission (CEs) of visual sustained attention in the high-SI group was 6.3 times higher on average than that of the low-SI group. After controlling for sex, age, and diagnosis, a higher number of CEs on visual sustained attention tasks predicted higher SI score. However, after controlling for sex, age, diagnosis, and depressive mood, this predictive ability was no longer observed.

CONCLUSION

This study showed that CE on the visual sustained attention task seems to influence suicidal ideation as a result of interaction with depressive symptoms.

Sustained vigilance is negatively affected by mild and acute sleep loss reflected by reduced capacity for decision making, motor preparation, and execution

Study Objectives

The behavioral and cognitive consequences of severe sleep deprivation are well understood. Surprisingly, relatively little is known about the neural correlates of mild and acute sleep restriction on tasks that require sustained vigilance for prolonged periods of time during the day.

Methods and Results

Event-related potential (ERP) paradigms can reveal insight into the neural correlates underlying visual processing and behavioral responding that is impaired with reduced alertness, as a consequence of sleep loss. Here, we investigated the impact of reduced vigilance following at-home mild sleep restriction to better understand the associated behavioral consequences and changes in information processing revealed by ERPs. As expected, vigilance was reduced (e.g. increased lapses and response slowing) that increased over the course of the experiment in the "sleep restricted" (5 hr sleep) compared with the "sleep-extension" (9 hr sleep) condition. Corresponding to these lapses, we found decreased positivity of visually evoked potentials in the Sleep Restriction vs. Sleep Extension condition emerging from 316 to 449 ms, maximal over parietal/occipital cortex. We also investigated electrophysiological signs of motor-related processing by comparing lateralized readiness potentials (LRPs) and found reduced positivity of LRPs in the Sleep Restriction vs. Sleep Extension condition at 70-40 ms before, and 115-158 ms after a response was made.

Conclusions

These results suggest that even a single night of mild sleep restriction can negatively affect vigilance, reflected by reduced processing capacity for decision making, and dulls motor preparation and execution.

Impaired neurobehavioral alertness quantified by the psychomotor vigilance task is associated with depression in the Wisconsin Sleep Cohort study

BACKGROUND

Excessive daytime sleepiness plays an important role in the presentation and course of mood disorders. Standard objective measures of daytime sleep propensity are of little to no value in depressive illness. This study examined the psychomotor vigilance task (PVT), an objective measure of neurobehavioral alertness, and its cross-sectional and longitudinal associations with depressive symptomatology in the Wisconsin Sleep Cohort Study.

METHODS

The sample consisted of 1569 separate 10-min PVT assessments conducted in 942 unique individuals. Cross-sectional and longitudinal conditional logistic regression models were used to estimate associations between the primary outcome of depression symptomatology (adjusted Zung scale≥50) and six separate PVT variables: mean reciprocal reaction time (1/RT); total lapses (RTs≥500 msec; LAPSE); total false responses (FALSE); reciprocal of the mean of the 10% fastest (FAST) and 10% slowest (SLOW) RTs; and slope of the linear regression line for all transformed 1/RTs (SLOPE).

RESULTS

In fully-adjusted cross-sectional models, 1/RT, LAPSE, FAST, and SLOW were each significantly associated with depression, such that worse neurobehavioral alertness was associated with higher odds of depressive symptomatology. Similar, though attenuated, findings were observed in fully-adjusted conditional longitudinal models that examined within-subject changes in depression status in the subset of participants with repeated PVT assessments. FALSE and SLOPE were not associated with depression in either cross-sectional or conditional longitudinal models.

CONCLUSIONS

These findings suggest components of the PVT are associated with depressive symptomatology. Further research is indicated to clarify the role of the PVT in the assessment of hypersomnolence in mood disorders.

Slow-wave activity surrounding stage N2 K-complexes and daytime function measured by psychomotor vigilance test in obstructive sleep apnea

STUDY OBJECTIVE

To better understand the inter-individual differences in neurobehavioral impairment in obstructive sleep apnea (OSA) and its treatment with continuous positive airway pressure (CPAP), we examined how changes in sleep electroencephalography (EEG) slow waves were associated with next-day psychomotor vigilance test (PVT) performance.

METHODS

Data from 28 OSA subjects (Apnea-Hypopnea Index with 3% desaturation and/or with an associated arousal [AHI3A] > 15/hour; AHI3A = sum of all apneas and hypopneas with 3% O2 desaturation and/or an EEG arousal, divided by total sleep time [TST]), who underwent three full in-lab nocturnal polysomnographies (NPSGs: chronic OSA, CPAP-treated OSA, and acute OSA), and 19 healthy sleepers were assessed. Four 20-minute PVTs were performed after each NPSG along with subjective and objective assessment of sleepiness. Three EEG metrics were calculated: K-complex (KC) Density (#/minute of N2 sleep), change in slow-wave activity in 1-second envelopes surrounding KCs (ΔSWAK), and relative frontal slow-wave activity during non-rapid eye movement (NREM) (%SWA).

RESULTS

CPAP treatment of OSA resulted in a decrease in KC Density (chronic: 3.9 ± 2.2 vs. treated: 2.7 ± 1.1; p < 0.01; mean ± SD) and an increase in ΔSWAK (chronic: 2.6 ± 2.3 vs. treated: 4.1 ± 2.4; p < 0.01) and %SWA (chronic: 20.9 ± 8.8 vs. treated: 26.6 ± 8.6; p < 0.001). Cross-sectionally, lower ΔSWAK values were associated with higher PVT Lapses (chronic: rho = -0.55, p < 0.01; acute: rho = -0.46, p = 0.03). Longitudinally, improvement in PVT Lapses with CPAP was associated with an increase in ΔSWAK (chronic to treated: rho = -0.48, p = 0.02; acute to treated: rho = -0.5, p = 0.03). In contrast, OSA severity or global sleep quality metrics such as arousal index, NREM, REM, or TST were inconsistently associated with PVT Lapses.

CONCLUSION

Changes in EEG slow waves, in particular ∆SWAK, explain inter-individual differences in PVT performance better than conventional NPSG metrics, suggesting that ΔSWAK is a night-time correlate of next-day vigilance in OSA.

Self-Reported Sleep, Anxiety, and Cognitive Performance in a Sample of U.S. Military Active Duty and Veterans

Unhealthy sleep can interfere with U.S. military service members affective and cognitive functioning, and increase accident and injury risks. This study examined the relationship between U.S. active duty and veterans' (n = 233) self-reported sleep (Pittsburgh Sleep Quality Index), anxiety (Zung Self-Rating Anxiety Scale), and cognitive performance (Automated Neuropsychological Assessment Metric). Statistical analyses included Pearson product moment correlations and multivariate analysis of variance, with Tukey-b post-hoc tests, with a p < 0.05 significance level. Higher education, abstinence from sleep aids, longer time in active duty service, and being on active duty were correlated with better sleep and lower anxiety. Greater sleep disturbance, poor sleep quality, and sleepiness-related daytime dysfunction were associated with greater anxiety and slower response times, and lower response accuracy. Statistically controlling for anxiety diminished the magnitude and significance of the correlations between sleep and cognitive performance, suggesting that reducing anxiety will improve sleep and diminish cognitive performance effects. These findings suggest the need for addressing both sleep and anxiety for those with diagnosed sleep disorders, as well as using a procedural systems approach to decrease anxiety during missions that demand outstanding cognitive performance.

The relationships between improvements in daytime sleepiness, fatigue and depression and psychomotor vigilance task testing with CPAP use in patients with obstructive sleep apnea

OBJECTIVE

The purpose of this study was to determine if the subjective improvements in daytime sleepiness, fatigue and depression experienced by patients with obstructive sleep apnea (OSA) with continuous positive airway pressure (CPAP) therapy predict an objective improvement in vigilance, and whether patients with mild-to-moderate OSA differ from patients with severe OSA in this regard.

METHODS

A total of 182 patients underwent psychomotor vigilance task (PVT) testing and measurements of subjective daytime sleepiness, fatigue and depression at baseline and after a minimum of one month of adherent CPAP use at an adequate pressure.

RESULTS

Patients with both mild-to-moderate (n = 92) and severe (n = 90) OSA experienced improvements in subjective daytime sleepiness, fatigue and depression, but objective improvement in vigilance was only seen in patients with severe OSA. In patients with severe OSA, while a correlation was found between improvements in daytime sleepiness and some PVT parameters, changes in subjective daytime sleepiness, fatigue and depression scores were not predictive of objective improvement in vigilance while controlling for all these subjective symptoms and for age, gender, body mass index, apnea-hypopnea index/respiratory event index and total sleep time/total recording time with pulse oximetry below 90%.

CONCLUSIONS

We found no predictive relationship between subjective improvements in daytime sleepiness, fatigue and depression and objective vigilance with CPAP use in patients with OSA. These results suggest that subjective complaints of daytime impairment and objective measures of vigilance in patients with OSA should be assessed separately while evaluating the efficacy of CPAP therapy on daytime functioning.

Measurement properties of tools used to assess depression in adults with and without autism spectrum conditions: A systematic review

Depression is the most commonly experienced mental health condition in adults with autism spectrum conditions (ASC). However, it is unclear what tools are currently being used to assess depression in ASC, or whether tools need to be adapted for this group. This systematic review therefore aimed to identify tools used to assess depression in adults with and without ASC, and then evaluate these tools for their appropriateness and measurement properties. Medline, PsychINFO and Web of Knowledge were searched for studies of depression in: (a) adults with ASC, without co‐morbid intellectual disability; and (b) adults from the general population without co‐morbid conditions. Articles examining the measurement properties of these tools were then searched for using a methodological filter in PubMed, and the quality of the evidence was evaluated using the COSMIN checklist. Twelve articles were identified which utilized three tools to assess depression in adults with ASC, but only one article which assessed the measurement properties of one of these tools was identified and thus evaluated. Sixty‐four articles were identified which utilized five tools to assess depression in general population adults, and fourteen articles had assessed the measurement properties of these tools. Overall, two tools were found to be robust in their measurement properties in the general population—the Beck Depression Inventory (BDI‐II), and the patient health questionnaire (PHQ‐9). Crucially only one study was identified from the COSMIN search, which showed weak evidence in support of the measurement properties of the BDI‐II in an ASC sample. Implications for effective measurement of depression in ASC are discussed. Autism Res2018, 11: 738–754. © 2018 The Authors Autism Research published by International Society for Autism Research and Wiley Periodicals, Inc.

Lay Summary

Depression is the most common mental health problem experienced by adults with autism. However, the current study found very limited evidence regarding how useful tools developed for the general population are for adults with autism. We therefore suggest how these tools could be adapted to more effectively assess depression in adults with autism, and improve these individuals access to mental health assessment and support.

The Prevalence of Sleep Disturbance and Its Socio-demographic and Clinical Correlates in First-episode Individuals With Schizophrenia in Rural China

PURPOSE

This study aimed to determine the prevalence and the socio-demographic and clinical correlates of sleep disturbance in first-episode individuals with schizophrenia in rural China and the factors that impact sleep among individuals with schizophrenia.

DESIGN AND METHODS

A total of 104 first-episode individuals with schizophrenia were randomly selected in rural areas in Ningxia, China, in 2015 as the study sample.

FINDINGS

In first-episode individuals with schizophrenia, the prevalence of sleep disturbance was 78.8% (82/104). Sleep disturbance was significantly associated with economic status, living situation, educational level, depressive symptoms, and anxiety symptoms.

PRACTICE IMPLICATIONS

Sleep disturbance is common in first-episode individuals with schizophrenia in rural China and more attention should be paid in clinical practice to improve the sleep quality for individuals with schizophrenia.

Association of Mild Obstructive Sleep Apnea With Cognitive Performance, Excessive Daytime Sleepiness, and Quality of Life in the General Population: The Korean Genome and Epidemiology Study (KoGES)

Study Objectives

Research points to impaired cognitive performance in sleep clinic patients with obstructive sleep apnea (OSA). However, inconsistent findings from various epidemiologic studies make this relationship less generalizable. The current study investigated the association between OSA and functional outcome measures, such as cognition, daytime sleepiness, and quality of life, in a Korean general population sample.

Methods

A total of 1492 participants from the Korean Genome and Epidemiology Study (KoGES) were included in the analyses. The presence of OSA measured by overnight polysomnography (PSG) was defined by apnea-hypopnea index (AHI) >5. Cognitive performance was determined with scores from a comprehensive neuropsychological battery. Excessive daytime sleepiness and quality of life were additionally measured through subjective reports.

Results

After adjusting for various demographic and medical characteristics, OSA was independently associated with lower performance in the Digit Symbol Test (52.73 ± 17.08 vs. 58.72 ± 18.03, OSA vs. not, p = .02). Hypoxia measures were not related to cognitive performance. OSA was associated with higher odds of displaying excessive daytime sleepiness (odds ratio = 1.72, 95% CI: 1.05-2.80), but there was no significant relationship between OSA and quality of life.

Conclusions

Cognition was unexpectedly unaffected overall. However, OSA was associated with impairment in a multidomain test that taps skills generally associated with frontal lobe function. The results suggest that research on protective and adaptive brain mechanisms to OSA stress can provide unique insights into the brain-sleep interface. As the study runs longitudinally, it will enable future studies on the impact of OSA on cognitive decline.

Objective, but Not Subjective, Sleepiness is Associated With Inflammation in Sleep Apnea

Study objectives

Objective and subjective measures of excessive daytime sleepiness (EDS) are only weakly associated. No study, however, has examined whether these two measures of EDS differ in terms of underlying mechanisms and prognostic value. Pro-inflammatory cytokines, that is, interleukin-6 (IL-6) appear to promote sleepiness/fatigue, while the stress hormone cortisol promotes vigilance. We hypothesized that objective sleepiness is associated with increased levels of IL-6 and decreased levels of cortisol.

Methods

We studied 58 obstructive sleep apnea (OSA) patients with clinical EDS and/or cardiovascular comorbidities who underwent 8-hour in-lab polysomnography for four consecutive nights. Objective and subjective daytime sleepiness were measured by Multiple Sleep Latency Test (MSLT), Epworth Sleepiness Scale (ESS), and Stanford Sleepiness Scale (SSS), respectively. Twenty-four-hour profiles of IL-6 and cortisol levels were assessed on the fourth day.

Results

The agreement between objective and subjective EDS in OSA patients was fair (kappa = 0.22). Objective EDS (lower MSLT) in OSA patients was associated with significantly elevated 24-hour (β = -0.34, p = .01), daytime (β = -0.30, p = .02) and nighttime (β = -0.38, p < .01) IL-6 levels, and significantly decreased daytime (β = 0.35, p = .01) cortisol levels. In contrast, subjective EDS (higher ESS/SSS) was not associated with either elevated IL-6 levels or decreased cortisol levels.

Conclusions

Our findings suggest that OSA with objective EDS is the more severe phenotype of the disorder associated with low-grade inflammation, a link to cardiometabolic morbidity and mortality. Compared to subjective EDS, objective EDS is a stronger predictor of OSA severity and may be useful in the clinical management of the disorder.

Sleep Duration of Inpatients With a Depressive Disorder: Associations With Age, Subjective Sleep Quality, and Cognitive Complaints

Sleep complaints and sleep disturbances are common in depression; however, the association of sleep duration and subjective sleep quality has been rarely investigated. Thus, subjective sleep quality and sleep duration were analyzed in depressed inpatients. Questionnaire data comprising clinical and sleep-related questions were sampled over a one-year period from adult inpatients with depressive syndromes. Sleep duration and items related to sleep quality were analyzed by means of group comparisons (sleep duration categories) and correlation analyses. Data of 154 patients (age 58.2±17.0 years, 63.6% women) were analyzed. Mean sleep duration was 7.2±2.1 h (16.9% of patients were below and 7.1% above age-specific recommendations), 25-40% of patients reported almost always daytime sleepiness, non-restorative sleep, attention deficits, or memory complaints with significant correlations between all variables (P<0.05). Sleep duration and sleep quality indicators showed significant curvilinear associations (quadratic contrast, P<0.05); i.e. extremely low and high sleep durations were associated with unfavorable sleep quality and subjective cognitive impairment. Non-recommended low or high sleep durations occur in a substantial proportion of patients with depression, and both were associated with poor sleep quality and subjectively impaired cognitive functions. Clinicians should be aware of these relationships. During hospitalization, a more individualized sleep-wake schedule should be applied.

Obstructive Sleep Apnea With Objective Daytime Sleepiness Is Associated With Hypertension

Subjective daytime sleepiness is considered a significant risk factor of hypertension in patients with obstructive sleep apnea (OSA). In this study, our goal was to examine the joint effect on hypertension of OSA and objective daytime sleepiness measured by the multiple sleep latency test (MSLT). A total of 1338 Chinese patients with OSA and 484 primary snorers were included in the study. All subjects underwent 1 night polysomnography followed by MSLT. The MSLT values were classified into 3 categories: >8 minutes, 5 to 8 minutes, and <5 minutes. Hypertension was defined based either on direct blood pressure measures or on diagnosis by a physician. After controlling for confounders, OSA combined with MSLT of 5 to 8 minutes increased the odds of hypertension by 95% (odds ratio, 1.95; 95% confidence interval, 1.10-3.46), whereas OSA combined with MSLT <5 minutes further increased the odds of hypertension by 111% (odds ratio, 2.11; 95% confidence interval, 1.22-3.31) compared with primary snorers with MSLT >8 minutes. In stratified analyses, the association of hypertension with MSLT in OSA patients was seen among both sexes, younger ages, both obese and nonobese patients, and patients with and without subjective excessive daytime sleepiness. We conclude that objective daytime sleepiness is associated with hypertension in patients with OSA.