Revisiting the maintenance of wakefulness test: from intra-/inter-scorer agreement to normative values in patients treated for obstructive sleep apnea

The Maintenance of Wakefulness Test is widely used to objectively assess sleepiness and make safety-related decisions, but its interpretation is subjective and normative values remain debated. Our work aimed to determine normative thresholds in non-subjectively sleepy patients with well-treated obstructive sleep apnea, and to assess intra- and inter-scorer variability. We included maintenance of wakefulness tests of 141 consecutive patients with treated obstructive sleep apnea (90% men, mean (SD) age 47.5 (9.2) years, mean (SD) pre-treatment apnea-hypopnea index of 43.8 (20.3) events/h). Sleep onset latencies were independently scored by two experts. Discordant scorings were reviewed to reach a consensus and half of the cohort was double-scored by each scorer. Intra- and inter-scorer variability was assessed using Cohen's kappa for 40, 33, and 19 min mean sleep latency thresholds. Consensual mean sleep latencies were compared between four groups according to subjective sleepiness (Epworth Sleepiness Scale score < versus ≥11) and residual apnea-hypopnea index (< versus ≥15 events/h). In well-treated non-sleepy patients (n = 76), the consensual mean (SD) sleep latency was 38.4 (4.2) min (lower normal limit [mean - 2SD] = 30 min), and 80% of them did not fall asleep. Intra-scorer agreement on mean sleep latency was high but inter-scorer was only fair (Cohen's kappa 0.54 for 33-min threshold, 0.27 for 19-min threshold), resulting in changes in latency category in 4%-12% of patients. A higher sleepiness score but not the residual apnea-hypopnea index was significantly associated with a lower mean sleep latency. Our findings suggest a higher than usually accepted normative threshold (30 min) in this context and emphasise the need for more reproducible scoring approaches.

Sleepiness should be reinvestigated through the lens of clinical neurophysiology: A mixed expertal and big-data Natural Language Processing approach

Historically, the field of sleep medicine has revolved around electrophysiological tools. However, the use of these tools as a neurophysiological method of investigation seems to be underrepresented today, from both international recommendations and sleep centers, in contrast to behavioral and psychometric tools. The aim of this article is to combine a data-driven approach and neurophysiological and sleep medicine expertise to confirm or refute the hypothesis that neurophysiology has declined in favor of behavioral or self-reported dimensions in sleep medicine for the investigation of sleepiness, despite the use of electrophysiological tools. Using Natural Language Processing methods, we analyzed the abstracts of the 18,370 articles indexed by PubMed containing the terms 'sleepiness' or 'sleepy' in the title, abstract, or keywords. For this purpose, we examined these abstracts using two methods: a lexical network, enabling the identification of concepts (neurophysiological or clinical) related to sleepiness in these articles and their interconnections; furthermore, we analyzed the temporal evolution of these concepts to extract historical trends. These results confirm the hypothesis that neurophysiology has declined in favor of behavioral or self-reported dimensions in sleep medicine for the investigation of sleepiness. In order to bring sleepiness measurements closer to brain functioning and to reintroduce neurophysiology into sleep medicine, we discuss two strategies: the first is reanalyzing electrophysiological signals collected during the standard sleep electrophysiological test; the second takes advantage of the current trend towards dimensional models of sleepiness to situate clinical neurophysiology at the heart of the redefinition of sleepiness.

Sleepiness and the transition from wakefulness to sleep

The transition from wakefulness to sleep is a progressive process that is reflected in the gradual loss of responsiveness, an alteration of cognitive functions, and a drastic shift in brain dynamics. These changes do not occur all at once. The sleep onset period (SOP) refers here to this period of transition between wakefulness and sleep. For example, although transitions of brain activity at sleep onset can occur within seconds in a given brain region, these changes occur at different time points across the brain, resulting in a SOP that can last several minutes. Likewise, the transition to sleep impacts cognitive and behavioral levels in a graded and staged fashion. It is often accompanied and preceded by a sensation of drowsiness and the subjective feeling of a need for sleep, also associated with specific physiological and behavioral signatures. To better characterize fluctuations in vigilance and the SOP, a multidimensional approach is thus warranted. Such a multidimensional approach could mitigate important limitations in the current classification of sleep, leading ultimately to better diagnoses and treatments of individuals with sleep and/or vigilance disorders. These insights could also be translated in real-life settings to either facilitate sleep onset in individuals with sleep difficulties or, on the contrary, prevent or control inappropriate sleep onsets.

Objective evaluation of excessive daytime sleepiness

Excessive daytime sleepiness (EDS) is multifactorial. It combines, among other things, an excessive propensity to fall asleep ("physiological sleepiness") and a continuous non-imperative sleepiness (or drowsiness/hypo-arousal) leading to difficulties remaining awake and maintaining sustained attention and vigilance over the long term ("manifest sleepiness"). There is no stand-alone biological measure of EDS. EDS measures can either capture the severity of physiological sleepiness, which corresponds to the propensity to fall asleep, or the severity of manifest sleepiness, which corresponds to behavioral consequences of sleepiness and reduced vigilance. Neuropsychological tests (The psychomotor vigilance task (PVT), Oxford Sleep Resistance Test (OSLeR), Sustained Attention to Response Task (SART)) explore manifest sleepiness through several sustained attention tests but the lack of normative values and standardized protocols make the results difficult to interpret and use in clinical practice. Neurophysiological tests explore the two main aspects of EDS, i.e. the propensity to fall asleep (Multiple sleep latency test, MSLT) and the capacity to remain awake (Maintenance of wakefulness test, MWT). The MSLT and the MWT are widely used in clinical practice. The MSLT is recognized as the "gold standard" test for measuring the severity of the propensity to fall asleep and it is a diagnostic criterion for narcolepsy. The MWT measures the ability to stay awake. The MWT is not a diagnostic test as it is recommended only to evaluate the evolution of EDS and efficacy of EDS treatment. Even if some efforts to standardize the protocols for administration of these tests have been ongoing, MSLT and MWT have numerous limitations: age effect, floor or ceiling effects, binding protocol, no normal or cutoff value (or determined in small samples), and no or low test-retest values in some pathologies. Moreover, the recommended electrophysiological set-up and the determination of sleep onset using the 30‑sec epochs scoring rule show some limitations. New, more precise neurophysiological techniques should aim to detect very brief periods of physiological sleepiness and, in the future, the brain local phenomenon of sleepiness likely to underpin drowsiness, which could be called "physiological drowsiness".

Better characterizing sleep beliefs for personalized sleep health promotion: the French sleep beliefs scale validation study

Background

The Sleep Beliefs Scale (SBS) is a well-known tool to design and monitor personalized sleep health promotion at an individual and population level. The lack of an established French version limits the development of effective interventions targeting these populations. Thus, the aim of this study was to validate the French version of the SBS in a representative sample of the general population.

Methods

Quota sampling was used to recruit 1,004 participants (18-65 years, mean age: 43 years, 54% of female) who underwent an online survey to complete the SBS, and to assess sleep schedules, sleep quality and disorders, and mental health. Cronbach's α coefficient, confirmatory factor analysis, item-internal consistency (IIC), and item discriminant validity (IDV) of the SBS were computed to assess internal validity while bivariate associations with sleep schedules, sleep quality and disorders, and mental health were used to assess external convergent and discriminant validity.

Results

The mean score on the SBS was 12.3 ± 4.9. Item 19 ("Quiet & Dark") showed the highest rate of correct answers (n = 801, 79.8%), while item 20 ("Recovering sleep") showed the lowest rate of correct answers (n = 246, 24.5%). Overall, the SBS showed satisfactory internal consistency (α = 0.87) and confirmed the three-factor structure proposed by the original study. All items were found consistent (IIC > 0.4) and discriminant (IIC > IDV) except for item 20 ("recovering lost sleep by sleeping for a long time"). Females, older participants, and subjects with short time-in-bed, poor sleep quality, insomnia, and circadian rhythm disorder had higher SBS scores while participants with depressive symptoms had lower SBS scores.

Conclusion

We successfully translated and validated the French version of the SBS in a representative sample, making it a reliable instrument for researchers and clinicians to assess and target sleep beliefs. Correct answers vary from 25 to 80% which underlines the importance of continuing sleep health promotion campaigns by targeting poorly understood behaviors. Our findings also shed light on the fickleness of beliefs that are prone to vary within individuals across time, in step with societal changes. Several associated factors were identified, thus contributing to our understanding of sleep beliefs and offering insights for personalized approaches to enhance sleep health and overall well-being.

Sleep timing, workplace well-being and mental health in healthcare workers

INTRODUCTION

Healthcare workers face an elevated risk of burnout, sleep disorders, and mental health issues, potentially stemming from the misalignment of their circadian rhythm due to nonstandard work schedules. This cross-sectional survey aims to examine the connections between sleep timing, workplace well-being (including burnout and absenteeism), and mental health outcomes (specifically depression and poor sleep) in healthcare workers. Additionally, the survey takes into account individual and professional factors, as well as the interaction with work schedules.

METHODS

The study encompasses 4,971 healthcare workers from both public and private healthcare facilities in France, including nurses, nursing assistants, and physicians recruited during the third wave of the COVID-19 pandemic. The Maslach Burnout Inventory assesses burnout, the Center for Epidemiologic Studies Depression Scale measures depression, and the Pittsburgh Sleep Quality Index evaluates poor sleep. Sleep timing is categorized into morning, neutral, and evening timing, referred to as midsleep. Multivariate logistic regression analysis is conducted to explore the relationships between sleep timing and burnout, depression, and poor sleep, while adjusting for various factors.

RESULTS

The findings reveal that 56.5% of participants experience burnout, 29.8% report depression, and 64.5% report poor sleep. Nurses and nursing assistants exhibit a higher prevalence of poor sleep. Morning sleep timing is associated with burnout among those with fixed schedules and with depression among those with shift schedules. Among physicians, both morning and evening sleep timing are associated with depression, while morning sleep timing is linked to poor sleep across all subgroups.

INTERPRETATION

This study suggests that the misalignment between healthcare workers' internal circadian rhythm and their work schedules may contribute to an increased risk of burnout, depression, and poor sleep. Occupational health services and policymakers should recognize the potential for enhancing workplace well-being and mental health outcomes by enabling healthcare workers to maintain sleep schedules that accommodate their needs.

Association between circadian sleep regulation and cortical gyrification in young and older adults

The circadian system orchestrates sleep timing and structure and is altered with increasing age. Sleep propensity, and particularly REM sleep is under strong circadian control and has been suggested to play an important role in brain plasticity. In this exploratory study, we assessed whether surface-based brain morphometry indices are associated with circadian sleep regulation and whether this link changes with age. Twenty-nine healthy older (55-82 years; 16 men) and 28 young participants (20-32 years; 13 men) underwent both structural magnetic resonance imaging and a 40-h multiple nap protocol to extract sleep parameters over day and night time. Cortical thickness and gyrification indices were estimated from T1-weighted images acquired during a classical waking day. We observed that REM sleep was significantly modulated over the 24-h cycle in both age groups, with older adults exhibiting an overall reduction in REM sleep modulation compared to young individuals. Interestingly, when taking into account the observed overall age-related reduction in REM sleep throughout the circadian cycle, higher day-night differences in REM sleep were associated with increased cortical gyrification in the right inferior frontal and paracentral regions in older adults. Our results suggest that a more distinctive allocation of REM sleep over the 24-h cycle is associated with regional cortical gyrification in aging, and thereby point towards a protective role of circadian REM sleep regulation for age-related changes in brain organization.

The Bordeaux Sleepiness Scale (BOSS): a new questionnaire to measure sleep-related driving risk

STUDY OBJECTIVES

Sleepiness is a well-known risk factor for traffic accidents. Our study presents a new questionnaire, the Bordeaux Sleepiness Scale (BOSS), specifically designed to evaluate sleep-related driving risk in patients with sleep disorders.

METHODS

The BOSS was designed by gathering data on sociodemographics, sleepiness, driving items, and traffic accident exposure (kilometers driven) in the past year of 293 patients followed for sleep disorders at a French sleep clinic. It was then validated on data from a large population-based cohort of 7,296 highway drivers. Its performance was compared to the Epworth sleepiness scale and to self-reported episodes of severe sleepiness at the wheel. Receiver operating characteristic curves were computed.

RESULTS

The sensitivity and specificity of the BOSS (cutoff = 3) to predict sleep-related near-misses or accidents was, respectively, 82% and 74%, with an area under the receiver operating characteristic curve of 0.83. In a cohort of patients and a large population-based cohort, the area under the curve of the BOSS was significantly larger than that of the Epworth sleepiness scale (P < .001). Although the areas under the curve were equivalent between the BOSS and sleepiness at the wheel, the specificity of the BOSS was higher.

CONCLUSIONS

The BOSS scale combining exposure (kilometers driven) and self-perception of situational sleepiness provides a simple and reliable evaluation of sleep-related driving risk. This short, specific questionnaire should be promoted as a first-line tool to evaluate the risk of traffic accidents in sleepy patients.

CITATION

Philip P, Micoulaud-Franchi J-A, Taillard J, et al. The Bordeaux Sleepiness Scale (BOSS): a new questionnaire to measure sleep-related driving risk. J Clin Sleep Med. 2023;19(5):957-965.

Emotional Exhaustion, a Proxy for Burnout, Is Associated with Sleep Health in French Healthcare Workers without Anxiety or Depressive Symptoms: A Cross-Sectional Study

Burnout is frequent among healthcare workers, and sleep problems are suspected risk factors. The sleep health framework provides a new approach to the promotion of sleep as a health benefit. The aim of this study was to assess good sleep health in a large sample of healthcare workers and to investigate its relationship with the absence of burnout among healthcare workers while considering anxiety and depressive symptoms. A cross-sectional Internet-based survey of French healthcare workers was conducted in summer 2020, at the end of the first COVID-19 lockdown in France (March to May 2020). Sleep health was assessed using the RU-SATED v2.0 scale (RegUlarity, Satisfaction, Alertness, Timing, Efficiency, Duration). Emotional exhaustion was used as a proxy for overall burnout. Of 1069 participating French healthcare workers, 474 (44.3%) reported good sleep health (RU-SATED > 8) and 143 (13.4%) reported emotional exhaustion. Males and nurses had a lower likelihood of emotional exhaustion than females and physicians, respectively. Good sleep health was associated with a 2.5-fold lower likelihood of emotional exhaustion and associations persisted among healthcare workers without significant anxiety and depressive symptoms. Longitudinal studies are needed to explore the preventive role of sleep health promotion in terms of the reduction in burnout risk.

Systematic Item Content and Overlap Analysis of Self-Reported Multiple Sleep Disorder Screening Questionnaires in Adults

Sleep disorders are defined on the basis of diagnostic criteria presented in medical classifications. However, no consensus has emerged on the exact list of operational symptoms that should be systematically investigated in the field of sleep medicine. We propose a systematic analysis of sleep symptoms that figure in a set of self-reported multiple sleep disorder screening questionnaires for adult populations, to identify the content overlap of symptoms that probe the presence of central sleep symptoms, and to highlight the potential level of heterogeneity among sleep disorder questionnaires. The method comprises three steps: (i) the selection of self-reported multiple sleep disorder screening questionnaires; (ii) item extraction and selection; (iii) the extraction of symptoms from items. Frequency of sleep symptoms and content overlap (Jaccard Index) are analyzed. We extracted 469 items that provide 60 different symptoms from 12 questionnaires. Insomnia, somnolence, and sleep-related breathing symptoms were found in all the questionnaires. The mean overlap among all questionnaires evaluated with the Jaccard Index is 0.44, i.e., moderate similarity. Despite limitations related to the selection of questionnaires and the symptom extraction and harmonization, this study underlines the need to standardize sleep symptom contents for sleep medicine in order to enhance the practicability, reliability, and validity of sleep disorder diagnoses.

Validity and diagnostic performance of a virtual reality-based supermarket application "MEMOSHOP" for assessing episodic memory in normal and pathological aging

Objective

MEMOSHOP is a virtual reality (VR)-based supermarket application for assessing episodic memory in aging. The aim of this study was to examine its construct validity against the gold standard paper-and-pencil neuropsychological test for clinical memory assessment in mild cognitive impairment (MCI) in older adults.

Methods

Patients with isolated subjective cognitive complaints (SCCs) or MCI were recruited in the Bordeaux Memory Clinic (MEMENTO cohort). Cognitively normal elderly controls were also recruited. MEMOSHOP allows a near-ecological evaluation of episodic memory during a usual daily life activity, i.e. shopping at the supermarket. MEMOSHOP and the gold standard Free and Cued Selective Reminding Test (FCSRT: French adaptation) were administered to all participants to assess episodic memory. Non-parametric tests and receiver operating characteristic curves were computed to compare their performances.

Results

Twenty-nine patients (21 females, age = 71 years ±7) and 29 matched controls were evaluated. The performance trends observed with MEMOSHOP and FCSRT on free and cued recall were associated (p < .01) and comparable (p < .0001), without any participants' groups interaction. Although easier than FCSRT in free recall for participants, MEMOSHOP demonstrated better diagnostic performance based on cued recall in isolated SCCs/MCI patients (p < .05).

Conclusion

MEMOSHOP demonstrated its reliability and validity for VR-based episodic memory assessment in the early stage of MCI and is potentially of interest for use in memory clinic settings.

A Systematic Review of Sleep–Wake Disorder Diagnostic Criteria Reliability Studies

The aim of this article is to provide a systematic review of reliability studies of the sleep–wake disorder diagnostic criteria of the international classifications used in sleep medicine. Electronic databases (ubMed (1946–2021) and Web of Science (—2021)) were searched up to December 2021 for studies computing the Cohen’s kappa coefficient of diagnostic criteria for the main sleep–wake disorder categories described in the principal classifications. Cohen’s kappa coefficients were extracted for each main sleep–wake disorder category, for each classification subtype, and for the different types of methods used to test the degree of agreement about a diagnosis. The database search identified 383 studies. Fifteen studies were analyzed in this systematic review. Insomnia disorder (10/15) and parasomnia disorder (7/15) diagnostic criteria were the most studied. The reliability of all sleep–wake disorders presented a Cohen’s kappa with substantial agreement (Cohen’s kappa mean = 0.66). The two main reliability methods identified were “test–retest reliability” (11/15), principally used for International Classification of Sleep Disorders (ICSD), and “joint interrater reliability” (4/15), principally used for Diagnostic and Statistical Manual of Mental Disorders (DSM) subtype diagnostic criteria, in particularl, the DSM-5. The implications in terms of the design of the methods used to test the degree of agreement about a diagnosis in sleep medicine are discussed.

0409 Self-perceived sleep during the Maintenance of Wakefulness Test: how does it predict accidental risk in patients with sleep disorders?

Introduction

The objective of this study is to determine whether the feeling of having slept or not during the Maintenance of Wakefulness Test (MWT) is associated with the occurrence of self-reported sleep-related traffic near misses and accidents in patients with sleep disorders.

Methods

This study was conducted in patients hospitalized in a French sleep center to perform a 4 × 40 min MWT. Relationship between mean sleep latency on the MWT, feeling of having slept or not during MWT trials and sleep-related near misses and accidents reported during the past year was analyzed.

Results

One hundred and ninety-two patients suffering from OSAS, idiopathic hypersomnia, narcolepsy, restless leg syndrome or insufficient sleep syndrome were included. One hundred and sixty-five patients presented no or one misjudgment of feeling of having slept during MWT trials while 27 presented more than two misjudgments. Almost half of the latter (48.1%) reported a sleepiness-related traffic near miss or accident in the past year versus only one third (27.9%) for the former (p &lt; 0.05). Multivariate logistic regression showed that patients with more than two misjudgments had a 2.52-fold (95% CI, 1.07–5.95, p &lt; 0.05) increase in the risk of reporting a sleepiness-related near miss/accident.

Conclusion

Misjudgment in self-perceived sleep during the MWT is associated with the occurrence of self-reported sleepiness-related traffic near misses and accidents in the past year in patients suffering from sleep disorders. Asking about the perception of the occurrence of sleep during the MWT could be used to improve driving risk assessment in addition to sleep latencies.

Support (If Any)

This was not an industry supported study. This project was supported by a grant from the French Sleep Society (SFRMS).

0046 Circadian misalignment is associated with Covid-19 infection

Introduction

Sleep disturbances are frequently reported in patients infected by Covid-19, but the role of sleep-wake behaviors as a risk factor to contract Covid-19 has up to now poorly been studied. The aim of this study was to explore the relationship between usual sleep-wake behaviors and the risk of Covid-19 infection in a population of subjects suspect of contact or infection with SARS-CoV-2.

Methods

Cross-sectionnal monocentric study set during a non-confined period in winter 2021. Recruitment took place in a Covid-19 ambulatory screening platform. Subjects between 18 and 45 years old were included whether they were symptomatic or not, healthcare workers or not, in contact with a Covid-19 case or not. They were asked about their usual sleep-wake behaviors. Usual sleep duration and sleep timing were explored during workdays and free days. Circadian misalignment was defined as at least 2 hours shift of circadian alignment (defined as the difference between mid‐sleep during workdays and mid‐sleep during free days, mid sleep as the middle between bedtime and getting up time).

Results

One thousand eighteen subjects were included in our study (acceptance rate: 10.8%, 39% of men, mean age of 28±8). Habitual mean sleep duration was equivalent in both groups (7h47 vs 7h49, p=0.733). Circadian misalignment greater than 2 hours concerned 33% of subjects in the Covid-19 group versus 20% of the control group (p=0.026). After adjustment on age, gender, BMI and work schedules, subjects presenting a circadian misalignment superior to 2 hours had 2.07 more chances to be tested positive than subjects which respected on identical sleep-wake timing between workdays and free days (OR=2.07, 95%CI= [1.12-3.80], p=0.024).

Conclusion

Altered sleep not only is present in subjects infected by Covid-19 but could be responsible of a higher change to be infected. Chronobiological impact on immune system and higher chances to be exposed to social contacts could explain our findings which deserve to be confirmed through a future large cohort study. Ultimately regular sleep-wake pattern could constitute a privileged prevention target to fight Covid-19 infection.

Support (If Any)

 

Smartphone-based virtual agents and insomnia management: A proof-of-concept study for new methods of autonomous screening and management of insomnia symptoms in the general population

Insomnia is the most frequent sleep disorder, and the COVID-19 crisis has massively increased its prevalence in the population, due to psychosocial stress or direct viral contamination. KANOPEE_2 is a smartphone-based application that provides interactions with a virtual agent to autonomously screen and alleviate insomnia symptoms through an intervention programme giving personalized advices regarding sleep hygiene, relaxation techniques and stimulus-control. In this proof-of-concept study, we tested the effects of KANOPEE_2 among users from all over the country (France) who downloaded the app between 1 June and 26 October 2020 (to focus on effects after the end of COVID-19 confinement). Outcome measures include insomnia severity (Insomnia Severity Index) and sleep/wake schedules measured by a sleep diary. One-thousand and thirty-four users answered the screening interview (M_age  = 43.76 years; SD = 13.14), and 108 completed the two-step programme (M_age  = 46.64 years; SD = 13.63). Of those who answered the screening, 42.8% did not report sleep complaints, while 57.2% presented mild-to-severe insomnia symptoms. At the end of the intervention, users reported significantly fewer sleep complaints compared with the beginning of the intervention (Insomnia Severity Index_beginning  = 13.58; Insomnia Severity Index_end  = 11.30; p < 0.001), and significantly increased their sleep efficiency (sleep efficiency_beginning  = 76.46%; sleep efficiency_end  = 80.17%; p = 0.013). KANOPEE_2 is a promising solution both to provide autonomous evaluation of individuals' sleep hygiene and reduce insomnia symptoms over a brief and simple intervention. These results are very encouraging for addressing the issue of insomnia management in people exposed to major psychosocial stress and the consequences of COVID-19 infection.

Sleep in Normal Aging, Homeostatic and Circadian Regulation and Vulnerability to Sleep Deprivation

In the context of geriatric research, a growing body of evidence links normal age-related changes in sleep with many adverse health outcomes, especially a decline in cognition in older adults. The most important sleep alterations that continue to worsen after 60 years involve sleep timing, (especially early wake time, phase advance), sleep maintenance (continuity of sleep interrupted by numerous awakenings) and reduced amount of sigma activity (during non-rapid eye movement (NREM) sleep) associated with modifications of sleep spindle characteristics (density, amplitude, frequency) and spindle-Slow Wave coupling. After 60 years, there is a very clear gender-dependent deterioration in sleep. Even if there are degradations of sleep after 60 years, daytime wake level and especially daytime sleepiness is not modified with age. On the other hand, under sleep deprivation condition, older adults show smaller cognitive impairments than younger adults, suggesting an age-related lower vulnerability to extended wakefulness. These sleep and cognitive age-related modifications would be due to a reduced homeostatic drive and consequently a reduced sleep need, an attenuation of circadian drive (reduction of sleep forbidden zone in late afternoon and wake forbidden zone in early morning), a modification of the interaction of the circadian and homeostatic processes and/or an alteration of subcortical structures involved in generation of circadian and homeostatic drive, or connections to the cerebral cortex with age. The modifications and interactions of these two processes with age are still uncertain, and still require further investigation. The understanding of the respective contribution of circadian and homeostatic processes in the regulation of neurobehavioral function with aging present a challenge for improving health, management of cognitive decline and potential early chronobiological or sleep-wake interventions.

Sleep deprivation therapy to reset the circadian pacemaker in a non-24-hour sleep-wake disorder: a case report

NONE

Non-24-hour sleep-wake disorder is 1 of several chronic circadian rhythm sleep-wake disorders. It is defined as progressive daily shifts in sleep onset and wake times. It mainly affects patients who are sight-impaired, is relatively rare in sighted patients, and is difficult to treat, with no guidelines. This case report discusses non-24-hour sleep-wake disorder in a sighted young man who complained of alternating severe insomnia and excessive sleepiness, with a sleep agenda and actigraphic data showing a daily delay of approximately 2 hours. A novel therapy by total sleep deprivation followed by a combination of morning light therapy and nocturnal melatonin administration was efficient in stopping his free-running sleep-wake pattern both immediately and in the long term. The treatment combination for 6 months resulted in stable circadian entrainment to a 24-hour cycle. Compliance with chronotherapy was maintained over the course of follow-up.

Automatic analysis of single-channel sleep EEG in a large spectrum of sleep disorders

STUDY OBJECTIVES

To assess the performance of the single-channel automatic sleep staging (AS) software ASEEGA in adult patients diagnosed with various sleep disorders.

METHODS

Sleep recordings were included of 95 patients (38 women, 40.5 ± 13.7 years) diagnosed with insomnia (n = 23), idiopathic hypersomnia (n = 24), narcolepsy (n = 24), and obstructive sleep apnea (n = 24). Visual staging (VS) was performed by two experts (VS1 and VS2) according to the American Academy of Sleep Medicine rules. AS was based on the analysis of a single electroencephalogram channel (Cz-Pz), without any information from electro-oculography nor electromyography. The epoch-by-epoch agreement (concordance and Conger's coefficient [κ]) was compared pairwise (VS1-VS2, AS-VS1, AS-VS2) and between AS and consensual VS. Sleep parameters were also compared.

RESULTS

The pairwise agreements were: between AS and VS1, 78.6% (κ = 0.70); AS and VS2, 75.0% (0.65); and VS1 and VS2, 79.5% (0.72). Agreement between AS and consensual VS was 85.6% (0.80), with the following distribution: insomnia 85.5% (0.80), narcolepsy 83.8% (0.78), idiopathic hypersomnia 86.1% (0.68), and obstructive sleep disorder 87.2% (0.82). A significant low-amplitude scorer effect was observed for most sleep parameters, not always driven by the same scorer. Hypnograms obtained with AS and VS exhibited very close sleep organization, except for 80% of rapid eye movement sleep onset in the group diagnosed with narcolepsy missed by AS.

CONCLUSIONS

Agreement between AS and VS in sleep disorders is comparable to that reported in healthy individuals and to interexpert agreement in patients. ASEEGA could therefore be considered as a complementary sleep stage scoring tool in clinical practice, after improvement of rapid eye movement sleep onset detection.

Self-perceived sleep during the Maintenance of Wakefulness Test: how does it predict accidental risk in patients with sleep disorders?

STUDY OBJECTIVES

To determine whether the feeling of having slept or not during the Maintenance of Wakefulness Test (MWT) is associated with the occurrence of self-reported sleep-related traffic near misses and accidents in patients with sleep disorders.

METHODS

This study was conducted in patients hospitalized in a French sleep center to perform a 4*40 min MWT. Relationship between mean sleep latency on the MWT, feeling of having slept or not during MWT trials and sleep-related near misses and accidents reported during the past year was analyzed.

RESULTS

192 patients suffering from OSAS, idiopathic hypersomnia, narcolepsy, restless leg syndrome or insufficient sleep syndrome were included. 165 patients presented no or one misjudgment of feeling of having slept during MWT trials while 27 presented more than two misjudgments. Almost half of the latter (48.1%) reported a sleepiness-related traffic near miss or accident in the past year versus only one third (27.9%) for the former (P<.05). Multivariate logistic regression showed that patients with more than two misjudgments had a 2.52-fold (95% CI, 1.07-5.95, P<.05) increase in the risk of reporting a sleepiness-related near miss/accident.

CONCLUSIONS

Misjudgment in self-perceived sleep during the MWT is associated with the occurrence of self-reported sleepiness-related traffic near misses and accidents in the past year in patients suffering from sleep disorders. Asking about the perception of the occurrence of sleep during the MWT could be used to improve driving risk assessment in addition to sleep latencies.

Brain reactivity to humorous films is affected by insomnia

STUDY OBJECTIVES

Emotional reactivity to negative stimuli has been investigated in insomnia, but little is known about emotional reactivity to positive stimuli and its neural representation.

METHODS

We used 3T fMRI to determine neural reactivity during the presentation of standardized short, 10-40-s, humorous films in insomnia patients (n=20, 18 females, aged 27.7 +/- 8.6 years) and age-matched individuals without insomnia (n=20, 19 females, aged 26.7 +/- 7.0 years), and assessed humour ratings through a visual analogue scale (VAS). Seed-based functional connectivity was analysed for left and right amygdala networks: group-level mixed-effects analysis (FLAME; FSL) was used to compare amygdala connectivity maps between groups.

RESULTS

fMRI seed-based analysis of the amygdala revealed stronger neural reactivity in insomnia patients than in controls in several brain network clusters within the reward brain network, without humour rating differences between groups (p = 0.6). For left amygdala connectivity, cluster maxima were in the left caudate (Z=3.88), left putamen (Z=3.79) and left anterior cingulate gyrus (Z=4.11), while for right amygdala connectivity, cluster maxima were in the left caudate (Z=4.05), right insula (Z=3.83) and left anterior cingulate gyrus (Z=4.29). Cluster maxima of the right amygdala network were correlated with hyperarousal scores in insomnia patients only.

CONCLUSIONS

Presentation of humorous films leads to increased brain activity in the neural reward network for insomnia patients compared to controls, related to hyperarousal features in insomnia patients, in the absence of humor rating group differences. These novel findings may benefit insomnia treatment interventions.

Does Homeostatic Sleep Pressure Buildup Explain Objective Excessive Daytime Sleepiness in Adults With ADHD? An Exploratory Study

Background: Excessive daytime sleepiness (EDS) is central in Attention deficit hyperactivity disorder (ADHD) but its causes remain unclear. The aim of this study was to explore objective EDS and homeostatic sleep pressure buildup, evaluated by power theta-alpha frequency (PTAF), in drug-free sleepy adults with ADHD and controls. Methods: Participants were placed during a 36-h period of extended wakefulness under constant routine protocol to strictly control sleep time, sleep duration, and circadian zeitgebers. Results: Eight drug-free sleepy patients with ADHD and 7 matched controls were included. The ADHD group had significantly shorter sleep latency on the Maintenance of Wakefulness Test (MWT) throughout extended wakefulness than the control group. There was no significant difference between the groups in PTAF evolution during extended wakefulness and in kinetic sleep pressure buildup, evaluated by the time constant of saturating exponential function. Limitations: The sample was small, so the findings cannot be generalized. Moreover, psychiatric comorbidities and circadian regulation should be taken into account in future studies. Conclusion: In very controlled conditions, mean sleep latency on the MWT during the whole extended wakefulness was significantly shorter in sleepy patients with ADHD than in control subjects. However, the difficulty to remain awake during soporific circumstances observed in these patients with ADHD cannot be explained by changes in the kinetic of sleep pressure buildup. Clinical Trials Registration: www.clinicaltrials.gov/, Identifier: NCT02217371.

Smartphone-Based Virtual Agents to Help Individuals With Sleep Concerns During COVID-19 Confinement: Feasibility Study

BACKGROUND

The COVID-19 crisis and consequent confinement restrictions have caused significant psychosocial stress and reports of sleep complaints, which require early management, have increased during recent months. To help individuals concerned about their sleep, we developed a smartphone-based app called KANOPEE that allows users to interact with a virtual agent dedicated to autonomous screening and delivering digital behavioral interventions.

OBJECTIVE

Our objective was to assess the feasibility of this app, in terms of inclusion rate, follow-up rate, perceived trust and acceptance of the virtual agent, and effects of the intervention program, in the context of COVID-19 confinement in France.

METHODS

The virtual agent is an artificial intelligence program using decision tree architecture and interacting through natural body motion and natural voice. A total of 2069 users aged 18 years and above downloaded the free app during the study period (April 22 to May 5, 2020). These users first completed a screening interview based on the Insomnia Severity Index (ISI) conducted by the virtual agent. If the users were positive for insomnia complaints (ISI score >14), they were eligible to join the 2-stage intervention program: (1) complete an electronic sleep diary for 1 week and (2) follow personalized sleep recommendations for 10 days. We collected and analyzed the following measures: sociodemographic information, ISI scores and sleep/wake schedules, and acceptance and trust of the agent.

RESULTS

Approximately 76% (1574/2069) of the app users completed the screening interview with the virtual agent. The virtual agent was well accepted by 27.4% (431/1574) of the users who answered the acceptance and trust questionnaires on its usability, satisfaction, benevolence, and credibility. Of the 773 screened users who reported sleep complaints (ISI score >14), 166 (21.5%) followed Step 1 of the intervention, and only 47 of those (28.3%) followed Step 2. Users who completed Step 1 found that their insomnia complaints (baseline mean ISI score 18.56, mean ISI score after Step 1 15.99; P<.001) and nocturnal sleep quality improved significantly after 1 week. Users who completed Step 2 also showed an improvement compared to the initial measures (baseline mean ISI score 18.87, mean ISI score after Step 2 14.68; P<.001). Users that were most severely affected (ISI score >21) did not respond to either intervention.

CONCLUSIONS

These preliminary results suggest that the KANOPEE app is a promising solution to screen populations for sleep complaints and that it provides acceptable and practical behavioral advice for individuals reporting moderately severe insomnia.

Objective Level of Alertness and Inhibitory Control Predict Highway Driving Impairment in Adults With ADHD

Objective: It remains unclear whether daytime impairments in ADHD patients are better explained by an altered level of alertness and/or by cognitive deficits. The aim of this study was to determine the respective contribution of these factors on driving performance in ADHD adults. Method: ADHD adults (n = 39) and healthy controls (n = 18) underwent a nocturnal polysomnography (PSG) followed by a Maintenance of Wakefulness Test (MWT), a simulated driving task, and a neuropsychological evaluation. Results: ADHD patients had shorter mean sleep latency on the MWT and worse driving performance than controls. They also made more errors on attention and executive functioning tests. Logistic regression analyses showed that inhibition deficits and objective daytime sleepiness predicted highway driving performance in ADHD. Conclusion: Our study shows that not only inhibitory control deficits but also pathological level of alertness independently contribute to highway driving impairment in ADHD patients, providing a better understanding of the pathophysiological mechanisms involved in ADHD.

Maintenance of wakefulness test: how does it predict accident risk in patients with sleep disorders?

STUDY OBJECTIVE

To determine whether the objective level of alertness measured by the Maintenance of Wakefulness Test (MWT) is associated with the occurrence of self-reported sleepiness-related traffic near misses and accidents related to sleepiness in patients with sleep disorders.

METHODS

This case-control study was conducted over a three-year period in four French sleep centers during a 4∗40 min MWT in patients driving more than 5000 Km/year. Relationship between mean sleep latency on the MWT (MWT latency) and age, sex, driving, sleepiness-related near misses and accidents reported during the previous year, and sleep disorder characteristics was analyzed.

RESULTS

Of 377 patients suffering from OSAS, idiopathic hypersomnia, narcolepsy, restless leg syndrome or insufficient sleep syndrome, 176 were included. 74 cases reported an accident or near miss related to sleepiness at the wheel in the past year, and 102 reported no accident/near miss (control patients). Thirty-one (37.8 %) cases and 9 (8.8 %) controls reported being sleepy at the wheel more than once a week (p < 0.0001). After adjusted regression analyses, patients with MWT latency between 19 and 33 minutes had a 3.2- (CI 95%[1.5; 6.8], p < 0.0001) fold increase in risk of reporting a near miss/ accident and patients with MWT latency <19 min had a 5.5- (CI 95%[2.2; 13.8], p = 0.003) fold increase in this risk, compared to the referent group (MWT latency>33 min).

CONCLUSIONS

MWT latency is associated with self-reported, sleepiness-related near misses and accidents related to sleepiness in the past year in patients routinely investigated in sleep clinics. The MWT could be used to assess driving risk together with clinical interviews assessing sleepiness at the wheel.

Excessive Daytime Sleepiness Measurements in Children With Attention Deficit Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) is the most commonly diagnosed neurodevelopmental disorder in childhood. It is a heterogeneous disorder in terms of clinical presentation that is probably due to the frequent occurrence of comorbidity. Children with ADHD more frequently report sleep disorders (notably delayed sleep phase syndrome) and excessive daytime sleepiness (EDS) than typically developing children. The aim of this article is to propose a narrative review of the assessment of EDS in the context of ADHD with first a summary of the subjective and objective tools used to measure it. Secondly, perspectives in terms of electroencephalogram (EEG) markers and neurofeedback are proposed. Then, possibilities for new kinds of evaluation are discussed (virtual reality, ecological momentary assessment, etc.). Lastly, we discuss specific clinical situations with EDS in the context of ADHD as links with narcolepsy, the comorbidity with other psychiatric disorders, and the context of sluggish cognitive tempo.

Acute Intake of a Grape and Blueberry Polyphenol-Rich Extract Ameliorates Cognitive Performance in Healthy Young Adults During a Sustained Cognitive Effort

Despite an increasing level of evidence supporting the individual beneficial effect of polyphenols on cognitive performance, information related to the potential synergistic action of these phytonutrients on cognitive performance during a prolonged cognitive effort is currently lacking. This study investigated the acute and sustained action of a polyphenols-rich extract from grape and blueberry (PEGB), on working memory and attention in healthy students during a prolonged and intensive cognitive effort. In this randomised, cross-over, double blind study, 30 healthy students consumed 600 mg of PEGB or a placebo. Ninety minutes after product intake, cognitive functions were assessed for one hour using a cognitive demand battery including serial subtraction tasks, a rapid visual information processing (RVIP) task and a visual analogical scale. Flow-mediated dilation (FMD) and plasma flavan-3-ols metabolites quantification were also performed. A 2.5-fold increase in serial three subtraction variation net scores was observed following PEGB consumption versus placebo (p < 0.001). A trend towards significance was also observed with RVIP percentage of correct answers (p = 0.058). No treatment effect was observed on FMD. Our findings suggest that consumption of PEGB coupled with a healthy lifestyle may be a safe alternative to acutely improve working memory and attention during a sustained cognitive effort.

Sleep Restriction, Sleep Hygiene, and Driving Safety: The Importance of Situational Sleepiness

Sleep-related accidents are a frequent cause of death and injury in the world. Poor sleep hygiene is responsible for sleep deprivation, which is clearly associated with an increased risk of accidents. Evidence shows that self-reported sleepiness at the wheel and reporting of inappropriate line-crossings are strong predictors of accident risk. Although the Epworth sleepiness scale is widely used in clinical practice, it is not the best to evaluate driving risks. Simple questions on the occurrence of near misses and sleepiness at the wheel should be asked systematically to address the issue of fitness to drive.

Non-REM Sleep Characteristics Predict Early Cognitive Impairment in an Aging Population

Objective: Recent research suggests that sleep disorders or changes in sleep stages or EEG waveform precede over time the onset of the clinical signs of pathological cognitive impairment (e.g., Alzheimer's disease). The aim of this study was to identify biomarkers based on EEG power values and spindle characteristics during sleep that occur in the early stages of mild cognitive impairment (MCI) in older adults. Methods: This study was a case-control cross-sectional study with 1-year follow-up of cases. Patients with isolated subjective cognitive complaints (SCC) or MCI were recruited in the Bordeaux Memory Clinic (MEMENTO cohort). Cognitively normal controls were recruited. All participants were recorded with two successive polysomnography 1 year apart. Delta, theta, and sigma absolute spectral power and spindle characteristics (frequency, density, and amplitude) were analyzed from purified EEG during NREM and REM sleep periods during the entire second night. Results: Twenty-nine patients (8 males, age = 71 ± 7 years) and 29 controls were recruited at T0. Logistic regression analyses demonstrated that age-related cognitive impairment were associated with a reduced delta power (odds ratio (OR) 0.072, P < 0.05), theta power (OR 0.018, P < 0.01), sigma power (OR 0.033, P < 0.05), and spindle maximal amplitude (OR 0.002, P < 0.05) during NREM sleep. Variables were adjusted on age, gender, body mass index, educational level, and medication use. Seventeen patients were evaluated at 1-year follow-up. Correlations showed that changes in self-reported sleep complaints, sleep consolidation, and spindle characteristics (spectral power, maximal amplitude, duration, and frequency) were associated with cognitive impairment (P < 0.05). Conclusion: A reduction in slow-wave, theta and sigma activities, and a modification in spindle characteristics during NREM sleep are associated very early with a greater risk of the occurrence of cognitive impairment. Poor sleep consolidation, lower amplitude, and faster frequency of spindles may be early sleep biomarkers of worsening cognitive decline in older adults.

[Validated tools for clinical evaluation of circadian rhythm sleep disorders in adults and children]

Circadian rhythm sleep-wake disorders are characterized either by sleep schedules that do not correspond to the usual schedules usually imposed by the light/dark cycle and by socio-professional activities, or by an unusual number of sleep episodes 24h. These two anomalies of the sleep-wake cycle are caused by an alteration of the circadian system or its mechanisms of entraining. The clinician has various tools that will confirm the diagnosis of circadian rhythm sleep-wake disorders. These diagnostic tools determine the alteration of the circadian system by generally estimating the circadian phase or else confirm the misalignment of sleep relative to the external environment. The purpose of this work is to provide the clinician with the various recommended or suggested (optional) tools to enable the diagnosis of each circadian rhythm sleep-wake disorders. These recommendations were developed by a consensus of SFRMS experts based more on their practice in the clinic than on a bibliographic study to highlight levels of evidence.

Association between reported sleep need and sleepiness at the wheel: comparative study on French highways between 1996 and 2011

OBJECTIVE

To investigate the evolution over 15 years of sleep schedules, sleepiness at the wheel and driving risk among highway drivers.

METHODS

Comparative survey including questions on usual sleep schedules and before the trip, sleepiness at the wheel, the Epworth sleepiness scale, Basic Nordic Sleep Questionnaire (BNSQ) and a travel questionnaire.

RESULTS

80% of drivers stopped by the highway patrol agreed to participate in both studies with a total of 3545 drivers in 2011 and 2196 drivers in 1996 interviewed. After standardisation based on sex, age and mean annual driving distance, drivers in 2011 reported shorter sleep time on week days (p<0.0001), and week-ends (p<0.0001) and shorter optimal sleep time (p<0.0001) compared to 1996 drivers. There were more drivers sleepy at the wheel in 2011 than in 1996 (p<0.0001) and 2.5 times more drivers in 2011 than in 1996 had an Epworth sleepiness score >15 indicating severe sleepiness.

CONCLUSIONS

Even if drivers in 2011 reported good sleep hygiene prior to a highway journey, drivers have reduced their mean weekly sleep duration over 15 years and have a higher risk of sleepiness at the wheel. Sleep hygiene for automobile drivers remains an important concept to address.

Impact of sleep apnea syndrome on survival in patients with multiple system atrophy

INTRODUCTION

Sleep apnea is very frequent in multiple system atrophy (MSA) and may contribute to the poor prognosis. The aim of the present study was to prospectively assess the relation between sleep apnea and survival in 30 consecutive MSA patients recruited at the French Reference Center for MSA.

METHODS

Patients with "probable" MSA according to current consensus diagnosis criteria were enrolled in this prospective cohort study. All patients received full polysomnography at baseline and were then followed for up to 4.5 years. The prognostic role of sleep apnea was assessed by a Cox model in an univariate analysis and then adjusted on other potential factors.

RESULTS

Analyzable polysomnographic recordings were available for 28 patients. Sleep apnea was found in 11 patients. During follow-up, 15 patients died, including 9 with baseline sleep apnea. In an univariate analysis, sleep apnea, Unified MSA Rating Scale I + II score at baseline and at year one, and disease duration were associated with mortality. However, when adjusting for disease duration and baseline Unified MSA Rating Scale score, the association between sleep apnea and mortality was no longer significant.

CONCLUSIONS

Sleep apnea was not an independent factor associated with mortality in this prospective cohort study.

Association between morningness/eveningness, addiction severity and psychiatric disorders among individuals with addictions

Studies have shown that Evening-Type (ET) subjects used more stimulating and sedative substances, and presented more psychiatric disorders than Morning-Type (MT) subject. However, there is a lack of data on the chronotype of patients with addiction. The aim of our study was to describe chronotype and associated factors in a sample of outpatients beginning treatment for addiction. Subjects were assessed with the Morningness-Eveningness questionnaire of Hörne & Ostberg, the Addiction Severity Index and the Mini International Neuropsychiatric Interview. In the 333 subjects with an addiction, 20% were MT and 32% were ET. When comparing ET to MT, multivariate analysis showed that ET was significantly associated with poly-problematic addiction, non-substance addictions, cannabis addiction, and mood disorders, but not with severity of addiction. MT was associated with antisocial personality disorder. Results suggested that chronotype was associated with specific addiction pattern and psychiatric disorders.

Attention Deficit Hyperactivity Disorder Symptoms, Sleepiness and Accidental Risk in 36140 Regularly Registered Highway Drivers

BACKGROUND

Attention Deficit Hyperactivity Disorder (ADHD) is a frequent neurodevelopmental disorder that increases accidental risk. Recent studies show that some patients with ADHD can also suffer from excessive daytime sleepiness but there are no data assessing the role of sleepiness in road safety in patients with ADHD. We conducted an epidemiological study to explore sleep complaints, inattention and driving risks among automobile drivers.

METHODS AND FINDINGS

From August to September 2014, 491186 regular highway users were invited to participate in an Internet survey on driving habits. 36140 drivers answered a questionnaire exploring driving risks, sleep complaints, sleepiness at the wheel, ADHD symptoms (Adult ADHD Self-Report Scale) and distraction at the wheel. 1.7% of all drivers reported inattention-related driving accidents and 0.3% sleep-related driving accidents in the previous year. 1543 drivers (4.3%) reported ADHD symptoms and were more likely to report accidents than drivers without ADHD symptoms (adjusted OR = 1.24, [1.03-1.51], p < .021). 14.2% of drivers with ADHD symptoms reported severe excessive daytime sleepiness (Epworth Sleepiness Scale >15) versus 3.2% of drivers without ADHD symptoms and 20.5% reported severe sleepiness at the wheel versus 7.3%. Drivers with ADHD symptoms reported significantly more sleep-related (adjusted OR = 1.4, [1.21-1.60], p < .0001) and inattention-related (adjusted OR = 1.9, [1.71-2.14], p<0001) near misses than drivers without ADHD symptoms. The fraction of near-misses attributable to severe sleepiness at the wheel was 4.24% for drivers without ADHD symptoms versus 10,35% for drivers with ADHD symptoms.

CONCLUSION

Our study shows that drivers with ADHD symptoms have more accidents and a higher level of sleepiness at the wheel than drivers without ADHD symptoms. Drivers with ADHD symptoms report more sleep-related and inattention-related near misses, thus confirming the clinical importance of exploring both attentional deficits and sleepiness at the wheel in these drivers. Road safety campaigns should be improved to better inform drivers of these accidental risks.

Excessive daytime sleepiness in adult patients with ADHD as measured by the Maintenance of Wakefulness Test, an electrophysiologic measure

OBJECTIVE

To quantify the objective level of sleepiness in adult attention-deficit/hyperactivity disorder (ADHD) patients and to determine the relationship between excessive daytime sleepiness and simulated driving performance.

METHOD

Forty adult ADHD patients (DSM-IV criteria) and 19 matched healthy control subjects were included between June 30, 2010, and June 19, 2013. All participants completed the Epworth Sleepiness Scale and the Manchester Driving Behavior Questionnaire. After nocturnal polysomnography, they performed 2 neuropsychological tests, a 4 × 40-minute Maintenance of Wakefulness Test, and a 1-hour driving session. The primary outcome measure was the mean sleep latency on the Maintenance of Wakefulness Test. ADHD patients were divided into 3 groups defined by their Maintenance of Wakefulness Test scores. Participants (patients and control subjects) were allocated as follows: sleepy ADHD (0-19 min), intermediate ADHD (20-33 min), alert ADHD (34-40 min), and control group (34-40 min). The driving performance outcome was the mean standard deviation of lateral position of the vehicle during the simulated session.

RESULTS

The group mean (SD) Epworth Sleepiness Scale score was higher in ADHD patients (12.1 [4.4]) than in controls (6.0 [2.7]) (P < .001). On the basis of the Maintenance of Wakefulness Test scores, 14 patients (35%) were in the sleepy group, 20 (50%) were in the intermediate group, and only 6 (15%) were in the alert group. Sleepy ADHD patients exhibited significantly deteriorated driving performance compared to the other 3 groups (P < .01).

CONCLUSIONS

Our study shows that a significant proportion of adult ADHD patients exhibit an objective excessive daytime sleepiness, which, in addition, has an impact on simulated driving performance. Excessive daytime sleepiness, therefore, may be a key element needed to better evaluate these ADHD patients.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01160874.

Complaints of Poor Sleep and Risk of Traffic Accidents: A Population-Based Case-Control Study

INTRODUCTION

This study aimed to determine the sleepiness-related factors associated with road traffic accidents.

METHODS

A population based case-control study was conducted in 2 French agglomerations. 272 road accident cases hospitalized in emergency units and 272 control drivers matched by time of day and randomly stopped by police forces were included in the study. Odds ratios were calculated for the risk of road traffic accidents.

RESULTS

As expected, the main predictive factor for road traffic accidents was having a sleep episode at the wheel just before the accident (OR 9.97, CI 95%: 1.57-63.50, p<0.05). The increased risk of traffic accidents was 3.35 times higher in subjects who reported very poor quality sleep during the last 3 months (CI 95%: 1.30-8.63, p<0.05), 1.69 times higher in subjects reporting sleeping 6 hours or fewer per night during the last 3 months (CI 95%: 1.00-2.85, p<0.05), 2.02 times higher in subjects reporting symptoms of anxiety or nervousness in the previous day (CI 95%: 1.03-3.97, p<0.05), and 3.29 times higher in subjects reporting taking more than 2 medications in the last 24 h (CI 95%: 1.14-9.44, p<0.05). Chronic daytime sleepiness measured by the Epworth Sleepiness Scale, expressed heavy snoring and nocturnal leg movements did not explain traffic accidents.

CONCLUSION

Physicians should be attentive to complaints of poor sleep quality and quantity, symptoms of anxiety-nervousness and/or drug consumption in regular car drivers.

Chronic artificial blue-enriched white light is an effective countermeasure to delayed circadian phase and neurobehavioral decrements

Studies in Polar Base stations, where personnel have no access to sunlight during winter, have reported circadian misalignment, free-running of the sleep-wake rhythm, and sleep problems. Here we tested light as a countermeasure to circadian misalignment in personnel of the Concordia Polar Base station during the polar winter. We hypothesized that entrainment of the circadian pacemaker to a 24-h light-dark schedule would not occur in all crew members (n = 10) exposed to 100-300 lux of standard fluorescent white (SW) light during the daytime, and that chronic non-time restricted daytime exposure to melanopsin-optimized blue-enriched white (BE) light would establish an a stable circadian phase, in participants, together with increased cognitive performance and mood levels. The lighting schedule consisted of an alternation between SW lighting (2 weeks), followed by a BE lighting (2 weeks) for a total of 9 weeks. Rest-activity cycles assessed by actigraphy showed a stable rest-activity pattern under both SW and BE light. No difference was found between light conditions on the intra-daily stability, variability and amplitude of activity, as assessed by non-parametric circadian analysis. As hypothesized, a significant delay of about 30 minutes in the onset of melatonin secretion occurred with SW, but not with BE light. BE light significantly enhanced well being and alertness compared to SW light. We propose that the superior efficacy of blue-enriched white light versus standard white light involves melanopsin-based mechanisms in the activation of the non-visual functions studied, and that their responses do not dampen with time (over 9-weeks). This work could lead to practical applications of light exposure in working environment where background light intensity is chronically low to moderate (polar base stations, power plants, space missions, etc.), and may help design lighting strategies to maintain health, productivity, and personnel safety.

Naturalistic conversation improves daytime motorway driving performance under a benzodiazepine: a randomised, crossover, double-blind, placebo-controlled study

The adverse effects of benzodiazepines on driving are widely recognised. The aims of this study were both to determine the impact of naturalistic conversation on the driving ability of drivers under a benzodiazepine, and to measure the accuracy of drivers' assessments of the joint effects of the benzodiazepine and conversation. Sixteen healthy male participants (29.69 ± 3.30 years) underwent a randomised, crossover, double-blind, placebo-controlled study with the benzodiazepine lorazepam (2mg). They drove 200 km (125 miles) on a motorway in the morning. We measured two driving ability-related variables (i.e., lane-keeping performance), and collected a set of self-assessed variables (i.e., self-assessment of driving performance) during two 10-min sequences of interest (no conversation vs. conversation). An analysis of variance revealed an interaction whereby lane-keeping performance under lorazepam was worse in the no-conversation condition than in the conversation condition. No such difference was detected under placebo. Pearson's correlation coefficients revealed that self-assessments were (i) not at all predictive of lane-keeping when performed before the drive, but (ii) moderately predictive of lane-keeping performance when performed during or after the drive. We conclude that conversation with a passenger may contribute to safer lane-keeping when driving under a benzodiazepine. Moreover, a degree of awareness may be attained after some experience of driving under the influence of this type of medication.

Modafinil improves real driving performance in patients with hypersomnia: a randomized double-blind placebo-controlled crossover clinical trial

STUDY OBJECTIVE

Patients with excessive daytime sleepiness (EDS) are at high risk for driving accidents, and physicians are concerned by the effect of alerting drugs on driving skills of sleepy patients. No study has up to now investigated the effect of modafinil (a reference drug to treat EDS in patients with hypersomnia) on on-road driving performance of patients suffering from central hypersomnia. The objective is to evaluate in patients with central hypersomnia the effect of a wake-promoting drug on real driving performance and to assess the relationship between objective sleepiness and driving performance.

DESIGN AND PARTICIPANTS

Randomized, crossover, double-blind placebo-controlled trial conducted among 13 patients with narcolepsy and 14 patients with idiopathic hypersomnia. Patients were randomly assigned to receive modafinil (400 mg) or placebo for 5 days prior to the driving test. Each condition was separated by at least 3 weeks of washout.

MEASUREMENTS

Mean number of Inappropriate Line Crossings, Standard Deviation of Lateral Position of the vehicle and mean sleep latency in the Maintenance of Wakefulness Test were assessed.

RESULTS

Modafinil reduced the mean number of Inappropriate Line Crossings and Standard Deviation of Lateral Position of the vehicle compared to placebo (F(1,25) = 4.88, P < 0.05 and F(1,25) = 3.87, P = 0.06 tendency). Mean sleep latency at the Maintenance of Wakefulness Test significantly correlated with the mean number of Inappropriate Line Crossings (r = -0.41, P < 0.001).

CONCLUSIONS

Modafinil improves driving performance in patients with narcolepsy and idiopathic hypersomnia. The Maintenance of Wakefulness Test is a suitable clinical tool to assess fitness to drive in this population.