Sleep Apnea

Sleep disorders in the newborn. Sleep disorders are classified in dyssomnias, parasomnias, sleep disorder associated with medical and psychiatric disorders and proposed sleep disorders. Only the parasomnias have been studied as such in the newborn period. The parasomnias that occur in this age group are infant sleep apnea, congenital central hypoventilation syndrome, sudden infant death syndrome, and benign neonatal sleep

What does lying down in bed for about 1/3 of your life do to your body and brain?  Are your sleep habits making you sick?  We show how common sleep positions can cause migraines, glaucoma, stroke, sleep apnea, sinus congestion, ear infections, facial distortion, and many other problems, which are reversible by changing the way you sleep.

Social jet lag is a term describing misalignment between social and biological time. In this paper it is argued that the currently used formula for social jet lag captures not only this misalignment, but also sleep debt. It is proposed to adopt the sleep-corrected formula for social jet lag, which takes the form of the difference between sleep onset on free days and workdays in the case of subjects with longer sleep and later/equal sleep onset on free days than workdays; it takes the form of the difference between sleep offset on free days and workdays for subjects with longer sleep and earlier/equal sleep offset on workdays than free days.

This review attempts to assemble the characteristics of a distinct variant of sleepwalking called sexsomnia/sleepsex from the seemingly scarce literature into a coherent theoretical framework. Common features of sexsomnia include sexual arousal with autonomic activation (e.g. nocturnal erection, vaginal lubrication, nocturnal emission, dream orgasms). Somnambulistic sexual behavior and its clinical implications, the role of precipitating factors, diagnostic, treatment, and medico-legal issues are also reviewed. The characteristics of several individuals described in literature including their family/personal history of parasomnia as well as the abnormal behaviors occurring during sleep are reported.

With the aging of the baby boomers, it is predicted that the US population over age 65 will grow from its 1999 level of 34.6 million persons to approximately 82 million in 2050, a 137% increase. The most rapid surge in our senior population will take place between 2011 and 2030. During this 19-year interval, seniors will expand from 13% of our population to 22% of our population.

The nose and pharynx begin the upper airway system and represent a continuum. This is the biologic basis for the mutual influences of rhinitis and obstructive sleep apnea (OSA). Sleep-disordered breathing has a large differential diagnosis that includes snoring, upper airway resistance syndrome, and severe OSA. Nasal obstruction is an independent risk factor for OSA, but there is no correlation of daytime nasal resistance with the severity of OSA. However, nasal resistance was an independent predictor of apnea-hypopnea index in a recent study of nonobese OSA patients. Rhinitis alone is associated with mild OSA, but commonly causes microarousals and sleep fragmentation. Reduction of nasal inflammation with topical treatment improves sleep quality and subsequent daytime sleepiness and fatigue. Patient compliance with the nasal continuous positive airway pressure (nCPAP) device is relatively low, in part due to adverse nasal effects.

A síndrome da apneia obstrutiva do sono (SAOS) é muito prevalente e ainda pouco reconhecida na população em geral. Entre os pacientes com hipertensão arterial sistêmica (HAS), a SAOS é encontrada em mais de um terço dos pacientes. Existem evidências crescentes de que a SAOS e a HAS frequentemente coexistem, não somente por terem fatores de risco comuns (obesidade, sedentarismo e idade) mas também porque a SAOS contribui para a gênese da HAS. A SAOS causa alterações hemodinâmicas e metabólicas não somente durante o sono, mas que persistem ao longo das 24 horas. Nesta breve revisão, serão discutidos os princípios fisiopatológicos envolvidos na síndrome da apneia obstrutiva do sono e sua interação com a HAS, como também as peculiaridades do seu tratamento com base nas mais recentes evidências de estudos clínicos.

Majority of the physiological processes in the human organism are rhythmic. The most common are the diurnal changes that repeat roughly every 24 hours, called circadian rhythms. Circadian rhythms disorders have negative influence on human functioning. The aim of this article is to present the current understanding of the circadian rhythms physiological role, with particular emphasis on the circadian rhythm sleep-wake disorders (CRSWD), principles of their diagnosis and chronobiological therapy. The guidelines are based on the review of
recommendations from the scientific societies involved in sleep medicine and the clinical experiences of the authors. Researchers participating in the preparation of guidelines were invited by the Polish Sleep Research Society and the Section of Biological Psychiatry of the
Polish Psychiatric Association, based on their significant contributions in circadian rhythm research and/or clinical experience in the treatment of such disorders. Finally, the guidelines were adjusted to the questions and comments given by the members of both Societies. CRSWD have a significant negative impact on human health and functioning. Standard methods used to assess CRSWD are sleep diaries and sleep logs, while the actigraphy, when available, should be also used. The most effective methods of CRSWD treatment are melatonin administration and light therapy. Behavioral interventions are also recommended. A fourteen-day period of sleep-wake rhythm assessment in CRSWD enables accurate diagnosis, adequate selection of chronobiological interventions, and planning adequate diurnal timing of their application. This type of assessment is quite easy, low-cost, and provides valuable indications how to adjust the therapeutic approach to the circadian phase of the particular patient.

Purpose No studies have assessed the prevalence of fatigue, depression, sleepiness, and the risk of obstructive sleep apnea (OSA) among commercial airlines pilots in the Gulf Cooperation Council (GCC). Methods This was a quantitative crosssectional study conducted among pilots who were on active duty and had flown during the past 6 months for one of three commercial airline companies. We included participants with age between 20 and 65 years. Data were collected using a predesigned electronic questionnaire composed of questions related to demographic information in addition to the Fatigue Severity Scale (FSS), the Berlin Questionnaire, the Epworth Sleepiness Scale (ESS), and the Hospital Anxiety and Depression Scale (HADS). Results The study included 328 pilots with a mean age ± standard deviation of 41.4 ± 9.7 years. Overall, 224 (68.3%) pilots had an FSS score ≥ 36 indicating severe fatigue and 221 (67.4%) reported making mistakes in the cockpit because of fatigue. One hundred and twelve (34.1%) pilots had an ESS score ≥ 10 indicating excessive daytime sleepiness and 148 (45.1%) reported falling asleep at the controls at least once without previously agreeing with their colleagues. One hundred and thirteen (34.5%) pilots had an abnormal HADS depression score (≥ 8), and 96 (29.3%) pilots were at high risk for OSA requiring further assessment. Conclusion Fatigue, sleepiness, risk of OSA, and depression are prevalent among GCC commercial airline pilots. Regular assessment by aviation authorities is needed to detect and treat these medical problems.

ments of diagnostic tests was very low. Thus, we are still not in a position to recommend standardization of diagnostic methodology for sleep apnea. Instead, our recommendations for future research include standardization of terms and diagnostic criteria, and consistently reported statistics to enhance the utility of this literature.

An anatomically accurate human upper airway model was constructed from multiple magnetic resonance imaging axial scans. This model was used to conduct detailed Computational Fluid Dynamics (CFD) simulations during expiration, to investigate the fluid flow in the airway regions where obstruction could occur. An identical physical model of the same airway was built using stereo lithography. Pressure and velocity measurements were conducted in the physical model. Both simulations and experiments were performed at a peak expiratory flow rate of 200 L/min. Several different numerical approaches within the FLUENT commercial software framework were used in the simulations; unsteady Large Eddy Simulation (LES), steady Reynolds-Averaged Navier-Stokes (RANS) with two-equation turbulence models (i.e. kÀe, standard kÀo, and kÀo Shear Stress Transport (SST)) and with one-equation Spalart-Allmaras model. The CFD predictions of the average wall static pressures at different locations along the airway wall were favorably compared with the experimental data. Among all the approaches, standard kÀo turbulence model resulted in the best agreement with the static pressure measurements, with an average error of $20% over all ports. The highest positive pressures were observed in the retroglossal regions below the epiglottis, while the lowest negative pressures were recorded in the retropalatal region. The latter is a result of the airflow acceleration in the narrow retropalatal region. The largest pressure drop was observed at the tip of the soft palate. This location has the smallest cross section of the airway. The good agreement between the computations and the experimental results suggest that CFD simulations can be used to accurately compute aerodynamic flow characteristics of the upper airway.

Approxi mately 3% of the middle-aged population suffer from excessive daytime sleepiness that may be the result of frequent nighttime sleep interruptions caused by upper airway disorders. Excessive sleep interruptions may interfere with the health and lifestyle of persons, causing them to be less productive in their work and to suffer an increased number of automobile and work related accidents. 1,2 The estimated cost to the economy for this disability is billions of dollars. 3 Other than the loss of production and increase in accident rate, upper airway sleep disorders may also be associated with potentially life-threatening medical conditions. The purpose of this article is to review the anatomic features and etiologic factors of upper airway sleep disorders and medical and dental treatment options.

Deficits in daytime performance due to sleep loss are experienced universally and associated with a significant social, financial, and human cost. Microsleeps, sleep attacks, and lapses in cognition increase with sleep loss as a function of state instability. Sleep deprivation studies repeatedly show a variable (negative) impact on mood, cognitive performance, and motor function due to an increasing sleep propensity and destabilization of the wake state. Specific neurocognitive domains including executive attention, working memory, and divergent higher cognitive functions are particularly vulnerable to sleep loss. In humans, functional metabolic and neurophysiological studies demonstrate that neural systems involved in executive function (i.e., prefrontal cortex) are more susceptible to sleep deprivation in some individuals than others. Recent chronic partial sleep deprivation experiments, which more closely replicate sleep loss in society, demonstrate that profound neurocognitive deficits accumulate over time in the face of subjective adaptation to the sensation of sleepiness. Sleep deprivation associated with disease-related sleep fragmentation (i.e., sleep apnea and restless legs syndrome) also results in neurocognitive performance decrements similar to those seen in sleep restriction studies. Performance deficits associated with sleep disorders are often viewed as a simple function of disease severity; however, recent experiments suggest that individual vulnerability to sleep loss may play a more critical role than previously thought.

Force Sensing Resistors (FSR) are ultra-thin, low-cost, pressure sensors, which exhibit change in their electrical resistance when force is applied on their surface. The FSR has been used in wide ranging applications in the automotive industry, musical instruments, touch-buttons, portable electronic devices, etc. The FSR is also proving to be promising device for developing applications in healthcare. The present work reviews the reported work on developing novel applications of FSR in non-invasive diagnosis, and monitoring of patients undergoing treatment. The techniques used in biosignal acquisition and its subsequent processing after using FSR, as reported in the literature are briefly reviewed. This is followed by review of the recently reported innovations in diagnostic technology using FSR. The applications of the FSR for diagnosis and monitoring of several major medical disorders are described. The merits and of using FSR are highlighted. The limitations of the technology using FSR are also noted for future advancement. It is observed that application of FSR, despite its present limitations of the technology, opens new opportunities for developing novel applications in bio-medical instrumentation and healthcare.

Objectives: In Europe, the services provided for the investigation and management of obstructive sleep apnoea (OSA) varies from country to country. The aim of this questionnaire-based study was to investigate the current status of diagnostic pathways and therapeutic approaches applied in the treatment of OSA in Europe, qualification requirements of physicians involved in diagnosis and treatment of OSA, and reimbursement of these services.

Obstructive sleep apnea (OSA) is a common sleep disorder which can result in mood problems. The aim of this study was to evaluate the severity of depression and anxiety symptoms as the most prevalent psychological disturbances present in different severity of OSA. We performed a cross-sectional study of 685 recently diagnosed sleep-disordered patients, over the age of 18, referred to Noor Sleep Lab from August 2008 to November 2010. The participants filled the Beck depression inventory-II (BDI-II) and the Beck anxiety inventory (BAI) to assess the depression and anxiety symptoms. We collected other characteristics of subjects such as age, sex, body mass index (BMI) and Epworth sleepiness scale (ESS). Apnea hypopnea index (AHI) was determined by an overnight polysomnography. Mean age of the participants was 47.63 years (SD 11.73). More than half of patient had some degrees of depression and anxiety. AHI showed no significant correlation with BDI (p = 0.105, r = −0.070) or BAI (p = 0.712, r = −0.016). Obesity was not either correlated with depression or anxiety (p = 0.18, r = 0.05). Nonetheless, ESS was weakly correlated with depression (p = 0.001, r = 0.148) and anxiety scores (p = 0.006, r = 0.120). BMI and ESS means were significantly higher in patients with severe OSA (p = 0.000). In comparison with men, the severity of depressive and anxiety symptoms was significantly higher in women (p = 0.000). In this cross-sectional study of patients with sleep problems, OSA was not associated with severity of depression and anxiety symptoms.

This thesis is concerned with developing and refining a collection of methods and tools which can be applied to the different steps of the Data Mining process. Data Mining is understood as the analysis of data using sophisticated tools and methods, which include aspects of data representation, data exploration, knowledge discovery, data modelling and data aggregation. Data Mining can be applied in real and complex domains, such as the domain of clinical prognosis, as well as with artificial test, or benchmark data. Medical informatics is a dynamic area where new approaches and techniques are constantly being developed, the objective being to improve current data representation, modelling and aggregation methods to achieve better diagnosis and prognosis. In this work we focus on two medical data domains: prognosis for ICU patients and diagnosis of Sleep Apnea cases, although it is proposed that the techniques have general use for any data domain. A key approach which is used for data processing and representation is that of fuzzy logic techniques. Existing techniques are benchmarked against the data, such as neural networks, tree induction and standard statistical analysis methods such as correlation, principal components and regression models.
We carry out a survey of existing techniques, authors and their approaches, in order to establish their strong and weak points, limitations, and opportunities where improvement may be achieved.
The first major area under consideration is data representation: how to define a unified scheme which encompasses different data types, such as numeric, continuous, ordered categorical, unordered categorical, binary and fuzzy; how to define membership functions; how to measure differences and similarities in the data. This is followed by a comprehensive benchmarking of existing AI and statistical algorithms on a real ICU medical dataset, comparing the ‘Data Mining’ results to methods proposed by the author.
We define  ‘fuzzy covariance’ as a  value which permits the measurement of relation between two fuzzy variables. Previous fuzzy covariance work was limited to the covariance of a fuzzy cluster to its fuzzy prototype [Gustafson79]. More recent authors [Nakamori97][Wangh95][Watada94] have created specialised fuzzy covariance calculations tailored for specific applications. In this work, a general fuzzy covariance algorithm, which measures the fuzzy covariance between two fuzzy variables, has been conceived, developed and tested. The initial work based the Hartigan joining algorithm and fuzzy covariances evolves into and is contrasted with the later work on data and attribute fusion using the WOWA aggregation operator .
‘Aggregation operators’ are considered as a method for modelling data for clinical diagnosis, and use ‘relevance’ and ‘reliability’ meta-data together with grades of membership to enhance the information which the aggregation operator receives in order to model the data. We also make enhancements to the WOWA operator, to enable it to process data with missing values and we develop a novel method for learning the weighting vectors.

Introduction: Insufficient sleep during polysomnography can produce poor quality studies or incomplete CPAP titrations. Non-benzodiazepines improve sleep without disrupting sleep architecture or exacerbating sleep-disordered breathing and should improve polysomnographic quality. Methods: Prospective, double-blinded, placebo-controlled trial assessing quality of polysomnography with eszopiclone premedication. We compared sleep latency, efficiency, sleep time and AHI between eszopiclone 3mg or matching placebo. We compared rates of inadequate studies between groups, defined as insufficient sleep time (<120 minutes or sleep efficiencies <70%) or incomplete CPAP titrations (>5 events/hour on the highest CPAP or complete intolerance).

OBJECTIVE: To investigate the prevalence of sleep breathing disorders, loud snoring and excessive daytime sleepiness in a group of obese subjects, and to identify the predictors of obstructive sleep apnea (OSA) severity in these patients.SUBJECTS: A total of 161 consecutive obese patients (body mass index (BMI)≥30.0 kg/m2), ranging between 30.0 and 67.3, represented by 57 men and 104 women, aged

The nature of the neurocognitive deficits found in obstructive sleep apnea is still debatable. What is the extent of higher executive versus alertness-based cognitive dysfunction? Are cognitive impairments caused by nighttime hypoxemia or daytime sleepiness? This paper demonstrates the importance of a sound theoretical neurocognitive framework to be able to answer these questions. A strategy to assess executive function is proposed and illustrated with well-known neuropsychological tests. It seems that the pervasive effects of decreased alertness on higher cognitive functioning were not fully taken into account in those studies in which executive dysfunction has been found and has been related to prefrontal lobe damage caused by intermittent hypoxemia. Therefore, a basal slowing in information processing, primarily due to sleepiness, may explain most of the neurocognitive deficits in sleep apnea. This conjecture appears to be in agreement with recent functional MRI studies indicating sleep loss as the primary cause of neurocognitive deficits, more so than hypoxemia.

Heart rate variability (HRV) ECG-derived respiration (EDR) Discrete wavelet transform (DWT) Fast-Fourier transform (FFT) Least square support vector machine (LS-SVM) Obstructive sleep apnea (OSA) a b s t r a c t Obstructive sleep apnea (OSA) is a highly prevalent sleep disorder. The traditional diagnosis methods of the disorder are cumbersome and expensive. The ability to automatically identify OSA from electrocardiogram (ECG) recordings is important for clinical diagnosis and treatment. In this study, we proposed an expert system based on discrete wavelet transform (DWT), fast-Fourier transform (FFT) and least squares support vector machine (LS-SVM) for the automatic recognition of patients with OSA from nocturnal ECG recordings. Thirty ECG recordings collected from normal subjects and subjects with sleep apnea, each of approximately 8 h in duration, were used throughout the study. The proposed OSA recognition system comprises three stages. In the first stage, an algorithm based on DWT was used to analyze ECG recordings for the detection of heart rate variability (HRV) and ECG-derived respiration (EDR) changes. In the second stage, an FFT based power spectral density (PSD) method was used for feature extraction from HRV and EDR changes. Then, a hill-climbing feature selection algorithm was used to identify the best features that improve classification performance. In the third stage, the obtained features were used as input patterns of the LS-SVM classifier. Using the cross-validation method, the accuracy of the developed system was found to be 100% for using a subset of selected combination of HRV and EDR features. The results confirmed that the proposed expert system has potential for recognition of patients with suspected OSA by using ECG recordings.

A 1991 National Institutes of Health Consensus Conference concluded that severely obese adults could be eligible for bariatric surgery if they had a body mass index (BMI) ≥35 kg/m2 with or ≥40 kg/m2 without obesity comorbidity. It was thought at that time that there were inadequate data to support bariatric surgery in severely obese adolescents. An estimated 25% of children in the United States are obese, a number that has doubled over a 30-year period. Very little information has been published on the subject of obesity surgery in adolescents. Therefore we reviewed our 20-year database on bariatric surgery in adolescents. Severely obese adolescents, ranging from 12 to less than 18 years of age, were considered eligible for bariatric surgery according to the National Institutes of Health adult criteria. Gastroplasty was the procedure of choice in the initial 3 years of the study followed by gastric bypass, which was found to be significantly more effective for weight loss in adults. Distal gastric bypass (D-GBP) was used in extremely obese patients (BMI ≥60 kg/m2) before 1992 and long-limb gastric bypass (LL-GBP) was used for super-obese patients (BMI ≥50 kg/m2) after 1992. Laparoscopic gastric bypass was used after 2000. Thirty-three adolescents (27 white, 6 black; 19 females, 14 males) underwent the following bariatric operations between 1981 and June 2001: horizontal gastroplasty in one, vertical banded gastroplasty in two, standard gastric bypass in 17 (2 laparoscopic), LL-GBP in 10, and D-GBP in three. Mean BMI was 52 ±11 kg/m2 (range 38 to 91 kg/m2), and mean age was 16 ± 1 years (range 12.4 to 17.9 years). Preoperative comorbid conditions included the following: type II diabetes mellitus in two patients, hypertension in 11, pseudotumor cerebri in three, gastroesophageal reflux in five, sleep apnea in six, urinary incontinence in two, polycystic ovary syndrome in one, asthma in one, and degenerative joint disease in 11. There were no operative deaths or anastomotic leaks. Early complications included pulmonary embolism in one patient, major wound infection in one, minor wound infections in four, stomal stenoses (endoscopically dilated) in three, and marginal ulcers (medically treated) in four. Late complications included small bowel obstruction in one and incisional hernias in six patients. There were two late sudden deaths (2 years and 6 years postop-eratively), but these were unlikely to have been caused by the bariatric surgical procedure. Revision procedures included one D-GBP to gastric bypass for malnutrition and one gastric bypass to LL-GBP for inadequate weight loss. Regain of most or all of the lost weight was seen in five patients at 5 to 10 years after surgery; however, significant weight loss was maintained in the remaining patients for up to 14 years after surgery. Comorbid conditions resolved at 1 year with the exception of hypertension in two patients, gastroesophageal reflux in two, and degenerative joint disease in seven. Self-image was greatly enhanced; eight patients have married and have children, five patients have completed college, and one patient is currently in college. Severe obesity is increasing rapidly in adolescents and is associated with significant comorbidity and social stigmatization. Bariatric surgery in adolescents is safe and is associated with significant weight loss, correction of obesity comorbidity, and improved self-image and socialization. These data strongly support obesity surgery for those unfortunate individuals who may have difficulty obtaining insurance coverage based on the 1991 National Institutes of Health Consensus Conference statement.

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.

All mammals and birds must develop effective strategies to cope with reduced oxygen availability. These animals achieve tolerance to acute and chronic hypoxia by (a) reductions in metabolism, (b) the prevention of cellular injury, and (c) the maintenance of functional integrity. Failure to meet any one of these tasks is detrimental. Birds and mammals accomplish this triple task through a highly coordinated, systems-level reconfiguration involving the partial shutdown of some but not all organs. This reconfiguration is achieved through a similarly complex reconfiguration at the cellular and molecular levels. Reconfiguration at these various levels depends on numerous factors that include the environment, the degree of hypoxic stress, and developmental, behavioral, and ecological conditions. Although common molecular strategies exist, the cellular and molecular changes in any given cell are very diverse. Some cells remain metabolically active, whereas others shut down or rely on anaerobic metabolism. This cellular shutdown is temporarily regulated, and during hypoxic exposure, active cellular networks must continue to control vital functions. The challenge for future research is to explore the cellular mechanisms and conditions that transform an organ or a cellular network into a hypometabolic state, without loss of functional integrity. Much can be learned in this respect from nature: Diving, burrowing, and hibernating animals living in diverse environments are masters of adaptation and can teach us how to deal with hypoxia, an issue of great clinical significance. 113 Annu. Rev. Physiol. 2007.69:113-143. Downloaded from arjournals.annualreviews.org by Brock University on 05/08/07. For personal use only. 114 Ramirez · Folkow · Blix Annu. Rev. Physiol. 2007.69:113-143. Downloaded from arjournals.annualreviews.org by Brock University on 05/08/07. For personal use only. www.annualreviews.org • Hypoxia Tolerance in Mammals and Birds 115 Annu. Rev. Physiol. 2007.69:113-143. Downloaded from arjournals.annualreviews.org by Brock University on 05/08/07. For personal use only. 116 Ramirez · Folkow · Blix Annu. Rev. Physiol. 2007.69:113-143. Downloaded from arjournals.annualreviews.org by Brock University on 05/08/07. For personal use only. 118 Ramirez · Folkow · Blix Annu. Rev. Physiol. 2007.69:113-143. Downloaded from arjournals.annualreviews.org by Brock University on 05/08/07. For personal use only.

Obstructive sleep apnea (OSA) is a disorder characterized by repetitive, episodic collapse of the pharyngeal airway. Over the last two decades, understanding of the pathophysiology of sleep disordered breathing, which includes OSA, has improved. Once thought to be predominately related to anatomic constriction of the maxillomandibular complex, central nervous system regulation of breathing is now recognized as a significant contributor to the pathogenesis of OSA. Ventilator control, the central response to chemoreceptor phenomena, has important implications for oral and maxillofacial surgeons who treat OSA, particularly for patients who appear refractory to treatment with maxillomandibular advancement (MMA). The purpose of this article is to review the biomechanics of the upper airway as it relates to the pathophysiology of OSA, to discuss emerging concepts of ventilator control mechanisms in normal sleep versus sleep-disordered breathing and to discuss the concept of complex sleep apnea, a new category of sleep disordered breathing with both obstructive and central features.

To study the prevalence of sleep-disordered breathing (SDB) in Vietnamera veterans. Methods: This was an observational study of Vietnam-era veterans using unattended, overnight polysomnography, cognitive testing, and genetic measures. Results: A sample of 105 Vietnam-era veterans with posttraumatic stress disorder: 69% had an Apnea Hypopnea Index >10. Their mean body mass index was 31, "obese" by Centers for Disease Control and Prevention criteria, and body mass index was significantly associated with Apnea Hypopnea Index (Spearman r = 0.41, N = 97, p < 0.0001). No significant effects of sleep-disordered breathing or apolipoprotein status were found on an extensive battery of cognitive tests. Conclusion: There is a relatively high prevalence of SDB in these patients which raises the question of to what degree excess cognitive loss in older PTSD patients may be due to a high prevalence of SDB. (Am J Geriatr Psychiatry 2012; 20:199-204) with PTSD compared with age-matched controls, especially in the areas of memory and attention. 2-5 A recent meta-analysis of 28 studies found an effect size of 0.82 of verbal memory impairment in PTSD versus control groups. The prevalence of sleepdisordered breathing (SDB) increases with age, and research indicates that SDB can also impair daytime cognitive function. 7-10 Furthermore, apolipoprotein (APOE)-4 carrier status in individuals with SDB has been found to impact cognitive function in an

Obstructive sleep apnea (OSA) is increasingly being recognized as a major health burden with strong focus on the associated cardiovascular risk. Studies from the last two decades have provided strong evidence for a causal role of OSA in the development of systemic hypertension. The acute physiological changes that occur during apnea promote nocturnal hypertension and may lead to the development of sustained daytime hypertension via the pathways of sympathetic activation, inflammation, oxidative stress, and endothelial dysfunction. This review will focus on the acute hemodynamic disturbances and associated intermittent hypoxia that characterize OSA and the potential pathophysiological mechanisms responsible for the development of hypertension in OSA. In addition the epidemiology of OSA and hypertension, as well as the role of treatment of OSA, in improving blood pressure control will be examined.

Traditional epidemiologic studies of insomnia provide valid but fairly rudimentary information regarding the presence, frequency, duration and evolution of sleep problems. Standardized tools such as validated questionnaires (e.g., Pittsburgh Sleep Quality Index and sleep logs) help assess the presence and severity of sleep problems, while other methods (e.g., SLEEP L system) address insomnia diagnoses. Other instruments (e.g., Structured Clinical Interview for DSM-IV [SCID], Short-Form 36 , Epworth Sleepiness Scale [ESS]) provide insights into insomnia consequences and co-morbidities. Sleep laboratory studies using polysomnography (PSG) have also provided useful findings (e.g., relating to sleep apnea and excessive daytime sleepiness) in experimental and population-based patient samples containing subgroups enriched for certain variables under investigation. These methods have significantly increased our knowledge about insomnia. Critically, longitudinal studies are needed to further our understanding of the pathophysiology and morbidity of insomnia, defining roles for risk factors, hyperarousal and co-morbidities and the effects of treatment in long-term disease progression. This review summarizes the current available data on the evolution of insomnia and proposes a model that warrants further research attention and discussion.

Background: The aim of this study was to determine in an open trial if physical exercise in sleep apnea patients is safe and/or influences respiratory disturbance index (RDI). Methods: After being treated 3 months or more with nasal CPAP for moderate to severe sleep apnea syndrome, eleven patients (1 female, 10 male, mean age 52.2 years) began a six-month period of supervised physical exercise twice a week, 2 hours each time. Before and after this period a Polysomnography without CPAP was recorded, along with a bicycle exercise test with lactate profile, echocardiography, body-weight, and body-height measurement. Results: No adverse effects or cardiopulmonary problems were observed. There was no significant change in body weight with physical training; no significant difference in either min SaO2 nor mean SaO2; and no significant improvement in fitness. No adverse cardiopulmonary effects or problems were observed. There was a decrease of the RDI from 32.8 to 23.6 (p < 0.05), without a significant change in the REM-sleep portion of total sleep time (TST), NREM sleep, or TST. Conclusions: A prescription for mild to moderate exercise is safe in the management of sleep apnea, and, even in the absence of a fitness improvement, there occurred a decrease in RDI without a change in sleep architecture.

Purpose Aims of our study are evaluating: (1) the prevalence of dolicofacial pattern among enuretic and control-group children, (2) the prevalence of an abnormal head posture in bedwetters, and (3) the correlation with sleep-related breathing disorders (SRBD) identified by polysomnography (PSG) recording. Nocturnal enuresis is a multifactorial disease, but has been related also to obstructive sleep-disordered breathing in both adults and children. Anatomical factors recognized to predispose to SRBD include adenotonsillar hypertrophy, neuromuscular disorders, craniofacial abnormalities associated with macroglossia, retrognathia or maxillary hypoplasia, and obesity. Methods Two hundred seventy enuretic children aged 7-12 years (mean 9.62±2.31) were compared with a controlmatched group of 274 children. To screen nocturnal sleep habits, all subjects' mothers filled out the Sleep Disturbance Scale for Children. Among these scales, only SBD scale was taken into account. Sleep breathing disorders (SBD) scale is composed of three items: sleep breathing difficulties, sleep apnea, and snoring. Cephalic index was calculated for each patient in order to identify facial patterns. An overnight PSG was performed in 28 (15 males, 13 females), randomly chosen, enuretic children and in 38 healthy volunteer controls (18 males, 20 females) matched for age (8.73±0.79 vs. 9.12±1.23; p=0.147) and sex distribution (chi-square=0.062; p=0.803). Results Bedwetters show different sleep habits, higher prevalence of dolicofacial pattern, and abnormal head posture more than controls. Conclusions Our preliminary study support further investigation of usage of the cephalic index as a predictor of SRBD.