Sleep Medicine

The field of memory and sleep is controversial and extremely interesting, and the relationships between thought processes, i.e. cognition and sleep, have recently been examined in a variety of clinical and basic research settings, as well as being the object of intense interest by the general public. For example, there are data which demonstrate that insomnia, as well as specific sleep disorders, can have a negative impact on sleep cognition as well as affect daytime patterns of cognitive functioning. Thus, sleep, disturbed sleep and the lack of sleep appear to affect cognitive and memory functions. An International Workshop dealing with Sleep and Cognitive Function: Research and Clinical Perspectives was convened in Cancún, Mexico, 1–4 March 1999 under the auspices of the World Health Organization Worldwide Project on Sleep and Health and the World Federation of Sleep Research Societies. A great number of areas of intersection between sleep and cognitive function were examined during the course of the Workshop, such as aging, cognition and sleep and the dream process and sleep. The results of these discussions are included in a WHO publication (WHO Doc.: MSD/MBD/00.8). In the present report we concentrate on presenting a summary of a coherent set of data which examine memory consolidation during sleep and the impact of insomnia on cognitive functions. Based upon these data, a review of memory and drug effects that are sleep-related, and an examination of the relationship between hypnotics and cognitive function are included. Finally, a summary of recommendations of the Workshop participants is presented.

Abstract 1. A satisfactory explanation of nightmares remains elusive. Theorists since Freud have speculated on mechanisms that produce nightmares, but no single, widely accepted explanation has emerged (see Nielsen & Levin, 2007b; Levin & Nielsen, 2007). This continuing uncertainty stems, in part, from the fact that nightmares, like dreams more generally, are expressions of human emotional memory--which itself is a complex and intransigent phenomenon. The inner workings of emotional memory have yet to be ...

This study aimed to assess the influence of snoring and sleep duration on developmental outcomes in 6 month old infants. As part of a longitudinal study of snoring in infancy, we identified 16 children (13 males) who commenced snoring shortly after birth and continued to snore frequently (≥ 3 nights/week) at 6 months of age and 88 healthy infant controls who were reported never to snore in the absence of a cold (36 males). Infants were assessed at 6 months of age with the Bayley Scales of Infant and Toddler Development Edition III, and parents completed demographic, sleep, and developmental surveys. Cognitive development was reduced in infants who snored frequently (mean=95.3; SD=4.3) from the first month of life compared to control infants (mean=100.6; SD=3.9) (F [1, 99]=23.8, p<.01; η(p)(2)=.21). Snoring during the first 6 months of life was associated with lower cognitive development scores. It is unknown whether these infants will continue to snore through childhood and, if s...

To determine the prevalence of sleep disturbance in a memory clinic population of Alzheimer's disease (AD) patients and identify its clinical correlates. Data from 215 attendees at a memory clinic, who were diagnosed with Alzheimer's disease, were examined. This included data from cognitive, functional and neuropsychological assessments. Sleep disturbance was determined using the question about diurnal rhythm disturbance on the BEHAVE-AD questionnaire. Two groups, with and without sleep disturbance, were compared. Group differences were analysed using univariate analysis and stepwise logistic regression analysis. The prevalence of sleep disturbance in this sample was 24.5%. The BEHAVE-AD 'aggressiveness' (P=0.009) and 'global rating' (P=0.029) (a measure of global impact of behavioural disturbance) were found to be significant predictors of sleep disturbance in AD. Sleep disturbance in AD is associated with other behavioural symptoms, notably aggressiveness. Sleep disturbance in AD has significant impact on the patient and/or caregiver. Consideration of co-morbid behavioural symptoms may aid the clinician in choosing a suitable treatment for sleep disturbance in AD.

The Aesthetics of Sleep: A study of sleep in Marcel Proust’s A la recherche du temps perdu.
This thesis examines the significance and structuring function of sleep and sleep related instances in Marcel Proust’s A la recherche du temps perdu (la Recherche). From the very first sentence, Longtemps, je me suis couché de bonne heure, toward the final vocation in Le Temps retrouvé the theme of sleep is pervasive throughout the novel. Descriptions of sleep occur on different levels in the narrative and suggest that the study itself should be conducted through various approaches. The thesis is thus organised around three main chapters, each seeking to examine how sleep engages with other crucial topics and adjacent phenomena in la Recherche.
The first chapter, on time and sleep, is concerned with the instability of narrative temporality and how the descriptions of sleep either destabilizes the narration or actually form a narrative pattern, to which the overall structure of the novel adheres. On another level the temporality of sleep, conceived as certain external or biological conditions for measuring time, affect the narration and particularly the narrator. The latter can be seen as a special narrating instance that, in a paradoxical way, manages to describe sleep while it happens, though still largely incapable of grasping the passing of time that occurs in sleep. Ultimately, the insomnia that inflicts the narrator is a disruption of temporality, since it breaks the habitual cycle of sleep.
The second chapter, concerning spatiality and sleep, focuses on various places where sleep occurs, most prominently the bedroom. From the very beginning of the novel, in the first five pages to be exact, the narrator’s bedroom appears as a privileged place where certain perceptual conditions are displayed and experimented with. Throughout the novel, places or settings that involve sleep or sleepers help shape the narrator’s social and artistic experiences. Sleep itself can also to some extent be seen as a necessary boundary or threshold that negotiates between inner and outer modes of perception. Furthermore sleep is often evoked through spatial imagery, for instance when sleep is depicted as a garden that the narrator enters. The reciprocal fashion in which sleep affects space as well as space affects sleep is finally summed up in the term soverum (sleep space).
The final chapter, concerning love and illness, takes its departure in various voyeuristic scenes where the narrator gains crucial insight into the world of love and illness by gazing at the sleeping other. The intermingling of the pathological and the erotic is intensified when the sleeping person is a loved one, such as the narrator’s girlfriend, Albertine. The jealousy that surmounts the narrator in the relationship with Albertine is put into perspective when he observes her sleeping body, and the significance of the sleeping individual as both (spiritually) abandoned and (bodily) available thus informs the narrator’s intermittent reflections on themes of love, jalousy and art. The chapter finally shows how the pathological and erotic share a mutual impulse, namely the interpretation of symptoms or signs that reveals the origin of suffering.
The thesis concludes by addressing, in more general terms, the potential problems involved when studying ‘sleep and literature’.

Introduction: We developed and validated an abbreviated Digital Sleep Questionnaire (DSQ) to identify common societal sleep disturbances including insomnia, delayed sleep phase syndrome (DSPS), insufficient sleep syndrome (ISS), and risk for obstructive sleep apnea (OSA). Methods: The DSQ was administered to 3799 community volunteers, of which 2113 were eligible and consented to the study. Of those, 247 were interviewed by expert sleep physicians, who diagnosed 2 sleep disorders. Machine Learning (ML) trained and validated separate models for each diagnosis. Regularized linear models generated 15e200 features to optimize diagnostic prediction. Models were trained with five-fold cross-validation (repeated five times), followed by robust validation testing. ElasticNet models were used to classify true positives and negatives; bootstrapping optimized probability thresholds to generate sensitivities, specificities, accuracies, and area under the receiver operating curve (AUC). Results: Compared to reference subgroups, physician-diagnosed sleep disorders were marked by DSQ evidence of sleeplessness (insomnia, DSPS, OSA), sleep debt (DSPS, ISS), airway obstruction during sleep (OSA), blunted circadian variability in alertness (DSPS), sleepiness (DSPS and ISS), increased alertness (insomnia) and global impairment in sleep-related quality of life (all sleep disorders). ElasticNet models validated each diagnosis with high sensitivity (80e83%), acceptable specificity (63e69%), high AUC (0.80 e0.85) and good accuracy (agreement with physician diagnoses, 68e73%). Discussion: A brief DSQ readily engaged and efficiently screened a large population for common sleep disorders. Powered by ML, the DSQ can accurately classify sleep disturbances, demonstrating the potential for improving the sleep, health, productivity and safety of populations.

We previously postulated how evolutionary changes in man's upper respiratory tract to facilitate speech, a phenomenon Jared Diamond calls The Great Leap Forward, have predisposed man to obstructive sleep apnea (OSA) [Diamond J. The Third Chimpanzee: the evolution and future of the human animal. New York: HarperCollins Publishers; 1992. p. 21, 23, 32–54, 54–6; Davidson TM. The Great Leap Forward: the anatomic evolution of obstructive sleep apnea. Sleep Medicine 2003;4:185–94]. We grouped these anatomic changes into four categories: klinorynchy, laryngeal descent, craniobase angulation and supralaryngeal vocal tract (SVT) ratio of SVTH:SVTV. This study was designed to investigate the relationship between cephalometric measures corresponding to these anatomic changes and OSA.One hundred and twenty-three male subjects presenting with symptoms of OSA underwent unattended multi-channel home sleep studies. We obtained cephalometric measurements from standard lateral cephalograms. Pearson correlation coefficients were calculated between cephalometrics and apnea–hypopnea index (AHI), age, and body mass index (BMI).Our results showed significant correlation between AHI and klinorynchy, laryngeal descent, and craniobase angulation.Overall, our data supports the theory that evolutionary anatomic changes to facilitate speech correlate with OSA severity. The cumulative changes in each cephalometric category trended in the directions hypothesized and support the Great Leap theory of OSA evolution.

Recently, seven single nucleotide polymorphisms (SNPs) of ARNTL, TIM and PER3 genes were found associated with affective temperaments in bipolar disorder patients. This study aimed to test whether a) the same associations appear in a non-clinical sample; b) the SNPs are related to other affective dimensions; c) the SNPs underpin the associations between chronotype and affective temperaments/dimensions. Three hundred thirty-eight university students completed the Temperament Scale of Memphis, Pisa, Paris and San Diego Auto-questionnaire, the Centre for Epidemiological Studies Depression Scale, the Perceived Stress Scale, the General Health Questionnaire, the Seasonal Pattern Assessment Questionnaire and the Composite Scale of Morningness. Seven SNPs of the ARNTL, TIM and PER3 genes were genotyped. According to nominal significance ARNTL rs7107287 was associated with a cyclothymic temperament, depressive and stress symptoms, general mental health and perceived negative impact of seasonality, while TIM rs10876890 was associated with a hyperthymic temperament and the TIM rs2291738 was associated with chronotype. Different SNPs were related to chronotype and affective temperaments/dimensions and therefore they seem to not underpin relationships between chronotype and affective dysfunction, i.e. in the present study eveningness was related to dysthymic, cyclothymic and irritable temperaments, more symptoms of depression, stress, worse mental health and a negative impact of seasonality, while morningness was related to hyperthymic temperament. The SNPs associations need further replication given that they did not achieve Bonferroni criteria of significance accounting for the number of polymorphisms considered and tests conducted.

Anecdotal reports suggest that sleep-disordered breathing (SDB) is common among patients with primary hypothyroidism. This study was undertaken to determine the prevalence of SDB and to evaluate the effect of thyroxine replacement therapy on SDB in patients with primary hypothyroidism.Fifty consecutive newly diagnosed, untreated symptomatic patients with primary hypothyroidism (age: 34±11 years; males: 21 [42%]) were prospectively studied. Physical examination, anthropometry, fasting blood glucose and serum lipids were performed in all patients at baseline. Polysomnography was done at baseline in all patients and was repeated after adequate thyroxine replacement in those who had SDB.SDB defined as apnea–hypopnea index (AHI) ≥5 was present in 15 patients (30%) at baseline and was reversible in 10 of the 12 patients evaluated following thyroxine replacement therapy (P=0.006). Thyroxine replacement therapy was associated with improvement in findings that reflect a compromised upper airway, such as macroglossia (4 [33%] vs. 1 [8%]; P=0.083), myoedema (5 [42%] vs. 1 [8%]; P=0.046) and facial puffiness (10 [83%] vs. 1 [8%]; P=0.003).Reversible SDB is common among patients with primary hypothyroidism. Changes in upper airway anatomy resulting from hypothyroidism probably contribute to the development of SDB in these patients.

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"It is a common experience that a problem difficult at night is resolved in the morning after the committee of sleep has worked on it." --John Steinbeck Scientific research confirms what people have always known: answers, ideas, and inspiration do come to us in dreams. Harvard psychologist and world-renowned dream specialist Deirdre Barrett, Ph.D., offers this rich collection of examples of how the world's most creative practitioners in art, music, film, science, literature and other fields have used the revelations of their dream life to inform their work. Dr. Barrett offers insights showing us how to encourage lucid, meaningful dreaming, and how to apply the meanings of our dreams to solving problems--from the everyday to the extraordinary. This is the stuff dreams are made of. In the visual arts, Jasper Johns couldn't find his unique artistic vision until he dreamed it in the form of a large American flag. Salvador Dali and his colleagues built the startling new genre of surrealism out of dreams. Kubla Kahn dreamed the design for his stately pleasure dome; thousands of years later, Lucy Davis, chief architect at a major firm, continues the tradition of dreaming designs into life in her extraordinary buildings. Film is a fertile avenue for dreams: "Twice I have transferred dreams to film exactly as I had dreamed them," confides director Ingmar Bergman, as have Federico Fellini, Orson Welles, Akira Kurosawa, Robert Altman, and John Sayles. From Mary Shelley's terrible nightmare, which became Frankenstein, to Stephen King's haunting dream as a little boy, which led to his first bestseller, countless writers have consulted the Committee. Musicians from Beethoven to Billy Joel and Paul McCartney have whistled the Committee's tunes. In science, physiologist Otto Loewi dreamed the medical experiment that earned him the Nobel Prize. In sports, Marion Jones dreamed she'd broken a world record, then brought the dream to life. Gandhi translated his dream of resistance into a movement that changed the world. Since Freud, we take it for granted that our dreams reflect our past. In The Committee of Sleep, Barrett reveals how dreams can also tell us about our future potential--and how to reach it.

A persons' health subsequently depends upon the level of his body composition. Its consist percentage of fat, bone, water, and muscle. Many health consultants around the world agreed that there is a health danger if the level of fat is too high in the human body. Presently it is clear that the factors of body composition are wide and involve multiple interfaces of cultural, environmental, social and lifestyle factors. A high level of fat percentage associated with a threat for health problems for stance high blood pressure, high blood cholesterol, diabetes, and sleeping disorder. Numerous studies found that there is an effect of sleep on body composition. Sleep is a natural process that allows the body and brain to rest and recover. Irregular sleep patterns, inadequate sleep quality, and insufficient sleep play a significant role to determine the health status of individuals. Quality of Sleep is not only effective as an indicator of health but also a key component of quality of life [1]. American adults reported around 27.5% to 29, 1% short sleep duration [2]. Numerous studies have investigated the relationship between obesity and sleep. Sleep apnea has an estimated prevalence of 9% to 28% among females and 27% to 34% among males, 30 to 70 years of age [3]. Every person requires sleep; both genders experiences sleep differently throughout their lifetimes. They face different challenges to sleep. Females are more prone to insomnia, while males are more likely to suffer from a sleep disorder like sleep apnea and snoring. Galland BC et al., reported poor sleep quality by 56% of participants and were more common in girls (63.1%) than in boys (44.5%), and sleep hygiene was significantly worse in females [4]. The symptoms for insomnia prevalence increased in females from 3.4% to 12.2% and in males from 4.3% to 9.1% [5]. The studies on sleep and body composition in the Saudi region on adolescent found that there is an inverse relationship between poor sleep duration (less than seven hours per day) and obesity/ overweight [6,7]. Mahfouz MS et al., revealed that university female students have poor sleep quality (69.1%) as they slept a mean of 4.77 hours/night [8]. In particular, epidemiological studies had shown a contrary correlation between sleep duration and BMI [9]. Sleep medicine in Saudi Arabia emphasising that there are many demands for further sleep studies to discuss the issues on the prevalence of numerous sleep disorders amongst Saudi population related to lifestyle and body composition [10]. Although longitudinal research is needed to confirm study results, researchers observed a counter relationship between duration of sleep and risk towards obesity development in children. In addition, every 30 minutes of sleep disruption leads to a 3% decline in daytime activity. Overall, study results indicate that sufficient duration and quality of sleep are significant factors for childhood obesity prevention [11]. Researchers found significant prediction between sleep duration in overweight male and z-score of BMI, where the long duration of sleep was linked with risk for overweight and lower BMI. In both regression models calculated for female adolescents, the duration of sleep is not a predictor for the risk of overweight or BMI z-score, indicating a gender difference in BMI and duration of sleep [12]. Many types of research are necessary to estimate how sleep effects on body composition, Inadequate sleep may also increase the chances to eat more, particularly if time spent in an inactive way, like browsing the internet, playing video games, watching television, even taking unhealthy foods habits. Daily routine work at home that leads to reduced sleep and increased food intake. However, the latest evidence linking BMI with sleep for a different population. There is little evidence for body fat, but not for the total body water with sleep habits for male and female students. In the present study authors investigated about body composition (BMI, body fat, and body water) and sleep habits amongst male and female students which would be helpful in identifying the effect of sleep habits on the body composition and adopt the preventive strategies for obesity and abnormal sleep. ABSTRACT Introduction: Elevated body composition is associated with many health hazards and it is also strongly associated with sleep habits of individuals.

Sleep is essential to cognitive function and health in humans, yet the ultimate reasons for sleep—i.e. 'why' sleep evolved—remain mysterious. We integrate findings from human sleep studies, the ethno-graphic record, and the ecology and evolution of mammalian sleep to better understand sleep along the human lineage and in the modern world. Compared to other primates, sleep in great apes has undergone substantial evolutionary change, with all great apes building a sleeping platform or 'nest'. Further evolutionary change characterizes human sleep, with humans having the shortest sleep duration , yet the highest proportion of rapid eye movement sleep among primates. These changes likely reflect that our ancestors experienced fitness benefits from being active for a greater portion of the 24-h cycle than other primates, potentially related to advantages arising from learning, socializing and defending against predators and hostile conspecifics. Perspectives from evolutionary medicine have implications for understanding sleep disorders; we consider these perspectives in the context of insomnia, narcolepsy, seasonal affective disorder, circadian rhythm disorders and sleep apnea. We also identify how human sleep today differs from sleep through most of human evolution, and the implications of these changes for global health and health disparities. More generally, our review highlights the importance of phylogenetic comparisons in understanding human health, including well-known links between sleep, cognitive performance and health in humans.

Manual processing of sleep recordings is extremely time-consuming. Efforts to automate this process have shown promising results, but automatic systems are generally evaluated on private databases, not allowing accurate cross-validation with other systems. In lacking a common benchmark, the relative performances of different systems are not compared easily and advances are compromised. To address this fundamental methodological impediment to sleep study, we propose an open-access database of polysomnographic biosignals. To build this database, whole-night recordings from 200 participants [97 males (aged 42.9+/-19.8 years) and 103 females (aged 38.3+/-18.9 years); age range: 18–76 years] were pooled from eight different research protocols performed in three different hospital-based sleep laboratories. All recordings feature a sampling frequency of 256 Hz and an electroencephalography (EEG) montage of 4–20 channels plus standard electro-oculography (EOG), electromyography (EMG), electrocardiography (ECG) and respiratory signals. Access to the database can be obtained through the Montreal Archive of Sleep Studies (MASS) website (http://www.ceams-carsm.ca/en/MASS), and requires only affiliation with a research institution and prior approval by the applicant’s local ethical review board. Providing the research community with access to this free and open sleep database is expected to facilitate the development and cross-validation of sleep analysis automation systems. It is also expected that such a shared resource will be a catalyst for cross-centre collaborations on difficult topics such as improving inter-rater  agreement on sleep stage scoring.