Abstract: The establishment of normal pediatric polysomnographic parameters is important for both clinical and research interests. Our objectives were to describe respiratory events, paradoxical breathing, periodic limb movements, and sleep architecture of children at the age of peak incidence of obstructive sleep apnea syndrome. We performed a retrospective cross-sectional analysis of a prospective cohort study of 66 children, 2-9 years old, at the Sleep Disorders Center at the Children's Hospital of Philadelphia. Subjects screened by questionnaire underwent a standard polysomnogram. The percent of total sleep time spent in sleep stages 1, 2, 3, 4, and rapid eye movement (REM) were 4 +/- 3%, 44 +/- 10%, 10 +/- 6%, 22 +/- 8%, and 21 +/- 6%, respectively. The arousal and awakening index was 11.2 +/- 4.3/hr. Respiratory events included a central apnea index of 0.08 +/- 0.14/hr, obstructive apnea index of 0.01 +/- 0.03/hr, and obstructive hypopnea index of 0.3 +/- 0.5/hr. The baseline arterial oxygen saturation (SpO2) was 97 +/- 1%, with a nadir of 92 +/- 3%. The index of periodic limb movements in sleep (PLMS) was 1.3 +/- 2.2/hr. Paradoxical breathing appeared significantly more frequent with piezo crystal effort belts (40 +/- 24% of epochs) than with respiratory inductive plethysmography (1.5 +/- 3% of epochs). We describe the occurrence of hypopneas during sleep, arousals and awakenings, and PLMS. We illustrate how different technologies can vary the apparent amount of paradoxical breathing. We also confirm previous data on the frequency distribution of sleep stages, SpO2, and relative rarity of respiratory events in this age group.

Abstract: STUDY OBJECTIVES To measure sympathetic responses in children with and without sleep-disordered breathing. DESIGN Prospective, observational study. SETTING Kosair Children's Hospital Sleep Medicine and Apnea Center. PARTICIPANTS Subjects were prospectively recruited from children undergoing overnight polysomnographic assessments and were retrospectively grouped according to the results of the polysomnogram. Sleep-disordered breathing was defined as an apnea-hypopnea index >5 and children were assigned to the control group if their apnea-hypopnea index was < 1. INTERVENTION N/A. MEASUREMENTS AND RESULTS During quiet wakefulness, pulse arterial tonometry was used to assess changes in sympathetic activity following vital capacity sighs in 28 children with sleep-disordered breathing and 29 controls. Each child underwent a series of 3 sighs, and the average maximal pulse arterial tonometry signal attenuation was calculated. Further, a cold pressor test was conducted in a subset of 14 children with sleep-disordered breathing and 14 controls. The left hand was immersed in ice cold water for 30 seconds while right-hand pulse arterial tonometry signal was continuously monitored during immersion and 20-minute recovery periods. Signal amplitude changes were expressed as percentage change from corresponding baseline. RESULTS The magnitude of sympathetic discharge-induced attenuation of pulse arterial tonometry signal was significantly increased in children with sleep-disordered breathing during sigh maneuvers (74.1% +/- 10.7% change compared with 59.2% +/- 13.2% change in controls; P<.0001) and the cold pressor test (83.5% +/- 7.3% change compared with 74.1% +/- 11.4% change in controls; P=.039). Further, recovery kinetics in control children were faster than those of children with sleep-disordered breathing. CONCLUSION Children with sleep-disordered breathing have altered autonomic nervous system regulation as evidenced by increased sympathetic vascular reactivity during wakefulness.

Abstract: STUDY OBJECTIVES Population-based studies have demonstrated associations between sleep-disordered breathing (SDB), hypertension, and cardiovascular disease; few large-scale studies have examined associations of SDB with objective measures of cerebrovascular disease. This study tested the significance of associations of SDB with evidence of brain injury or ischemia determined by cerebral magnetic resonance imaging (MRI) studies. DESIGN Cross-sectional and longitudinal analyses in a nested sample of Cardiovascular Health Study participants in the Sleep Heart Health Study. PARTICIPANTS The 843 individuals (mean age 77, SD 4.3 years, 58% women) who had MRI studies as part of the Cardiovascular Health Study before and after polysomnography obtained as part of the Sleep Heart Health Study. MEASUREMENTS A 12-channel polysomnogram was used to derive indexes of sleep-disordered breathing. Repeated MRI measurements provided indexes of infarct (presence and size) and white matter disease. Logistic regression analyses were used to model MRI changes of infarct-like lesions and white matter disease as a function of age, baseline white matter grade, and indexes of central and obstructive sleep-disordered breathing. RESULTS Individuals who showed progression in white matter disease compared to those who did not were significantly more likely to show a Cheyne-Stokes respiration pattern and to have an increased number of central but not obstructive apneas. CONCLUSIONS An association between change in white matter grade and measures of central sleep apnea was demonstrated that was consistent with a causal pathway in which central sleep apnea contributes to the progression of white matter disease; alternatively, central sleep apnea may be a marker of subclinical cerebrovascular or cardiovascular disease.

Abstract: Study objectives Breath-to-breath variability is not purely random but is, instead, characterized by correlations on short- and long-term scales. Short-term correlations might reflect intact metabolic-control mechanisms. To investigate whether the higher variability of breathing during rapid eye movement (REM) compared to non-REM (NREM) sleep is of random or nonrandom nature--reflecting an altered respiratory control--short-term and long-term correlations of respiratory drive and timing were determined. Design A full-night polysomnogram with a pneumotachograph attached to a full-face mask was performed. For each breath during NREM and REM sleep, respiratory components were analyzed based on the quantitative airflow. Setting Data collection took place in the sleep laboratory. Participants Twenty-nine healthy subjects (age, 25.8 +/- 3.1 years). Measurements and results Long-term correlations are practically absent in respiratory timing and drive components during NREM sleep, whereas they are present during REM sleep. Short-term correlations are present in respiratory drive, tidal volume, and minute ventilation during both NREM and REM sleep. In all timing components, additional short-term correlations are absent. Conclusion We conclude that from NREM to REM sleep, short-term regulation of respiratory drive remains strongly metabolically controlled and clearly different from the short-term regulation of the rhythm-generating function. Regulation of respiratory timing and drive during REM sleep is characterized by additional long-term correlations. We speculate that this is the result of cortical influences during phasic REM sleep. Thus, the variability of breathing during REM sleep contains a nonrandom component, such that breathing components remain dependent upon each other even with large time lags between components.

Abstract: Purpose of review In recent years several daytime symptoms resulting from pediatric obstructive sleep apnea have been recognized that affect neurobehavioral and cognitive functioning. It is important to identify patients who will benefit from treatment. Up until now the systematic analysis of obstructive sleep apnea in children has been hindered by both variable diagnostic criteria and patient care protocols. This review examines the effects of obstructive sleep apnea in children as well as treatment outcomes. Recent data suggest that some diagnostic modalities may underestimate the prevalence of sleep-disordered breathing in children. Recent findings A review of the data from the past year shows a significant correlation between obstructive sleep apnea and daytime symptoms. It also shows mitigation of these symptoms with appropriate treatment. The directed history and physical examination continue to be the most effective means of diagnosis in most affected children. The polysomnogram is considered the gold standard for diagnosis but may underestimate the presence of sleep-disordered breathing in children. Some children with the diagnosis of primary snoring will benefit from treatment. Summary In view of the profound effects of obstructive sleep apnea in children, it is vital to develop an accurate and universal system for diagnosing and treating these patients. Adenotonsillar hypertrophy is the major cause of obstructive sleep apnea in children. A directed history and physical examination followed by tonsillectomy and adenoidectomy are effective in improving the physical sequelae and quality of life of affected children.

Abstract: Polysomnographic events comprise a wide variety of phenomena,including episodes of apnea, episodes of hypopnea, leg movements, transient central nervous system arousals, and eye movements. The process of event scoring involves pattern recognition and provides a description of potentially pathophysiologic activity occurring during sleep. The rules for scoring sleep-related events continue to be developed. The rules are precise and must be followed with extreme care. When the polysomnogram is interpreted,the report must include a summary of event scoring and clinical correlation to the sleep complaint. Arousals, periodic limb movements, and respiratory events are significant because they represent pathophysiologies on which final diagnosis largely depends.

Abstract: Sleep stage scoring is a system-based classification procedure requiring knowledge and understanding of brainwave electrical potentials and their patterns in different cortical areas. Monitoring precise scalp locations requires standardized electrode placements. The electroencephalogram is recorded concurrently with eye movement potentials (electro-oculogram) and submentalis muscle activity (electromyogram). The resulting recording is a polysomnogram. This article addresses sleep stage scoring in adults.

Abstract: Publisher Summary This chapter describes the multiple sleep latency test (MSLT). The MSLT is the most commonly used method for objective evaluation of daytime sleepiness. This test measures speed of falling asleep on a series of naps, which directly correlates with levels of sleepiness. Thus excessive daytime sleepiness (EDS) is indicated by more rapid sleep onsets than normal control levels. The MSLT has achieved widespread acceptance because of its simple, intuitive approach to sleepiness. Furthermore, the MSLT provides several opportunities to test for sleep-onset rapid eye movement (REM) episodes, the primary diagnostic sign of narcolepsy. The MSLT procedure is well-standardized according to the guidelines set out by the American Academy of Sleep Medicine. An overnight polysomnogram is carried out the night before the MSLT to examine both the quality and quantity of the night's sleep, which influence the MSLT results. It is ideal that subjects complete sleep diary forms or otherwise have their sleep assessed (e.g., actigraphy) for MSLT may be influenced by sleep for up to seven nights before the test.

Abstract: Sleep-disordered breathing is a chronic problem of the inappropriate mechanical collapse of the upper airway. Symptoms range from mild occasional snoring to severe obstructive sleep apnea. The standard of care for the diagnosis and treatment of sleep-disordered breathing by sleep medicine has been the use of the polysomnogram and continuous positive airway pressure. This approach is burdensome, costly, and ineffective due to lack of compliance with or rejection of treatment. Oral appliances are highly effective in managing the mild snorer to the moderate sleep apneic and are approaching the efficacy of continuous positive airway pressure with the severe apneic. The dentist can and should manage these patients. However, the dental practitioner must acquire sufficient training and knowledge to appropriately treat these patients.

Abstract: Physiologic stresses have been reported to cause a lack of zinc. Obstructive sleep apnea syndrome (OSAS) is a disorder that gives stress, including sleep deprivation or hypoxia. Therefore, it is predicted that the serum zinc level might be decreased in OSAS patients. We studied 16 patients with OSAS who underwent polysomnogram. Of the 16 cases of the OSAS group, 5 cases showed hypozincemia, whereas no cases showing hypozincemia were observed in the non-OSAS group. The χ2-test revealed P < 0.05. Although administration of zinc was not performed until the time of blood drawing, three of the four cases with hypozincemia showed improvement.

Abstract: Sleep difficulty is one of the hallmarks of menopause. Following recent studies showing no cardiac benefit and increased breast cancer, the question of indications for hormonal therapy has become even more pertinent. Three sets of sleep disorders are associated with menopause: insomnia/depression, sleep disordered breathing and fibromyalgia. The primary predictor of disturbed sleep architecture is the presence of vasomotor symptoms. This subset of women has lower sleep efficiency and more sleep complaints. The same group is at higher risk of insomnia and depression. The "domino theory" of sleep disruption leading to insomnia followed by depression has the most scientific support. Estrogen itself may also have an antidepressant as well as a direct sleep effect. Treatment of insomnia in responsive individuals may be a major remaining indication for hormone therapy. Sleep disordered breathing (SDB) increases markedly at menopause for reasons that include both weight gain and unclear hormonal mechanisms. Due to the general under-recognition of SDB, health care providers should not assume sleep complaints are due to vasomotor related insomnia/depression without considering SDB. Fibromyalgia has gender, age and probably hormonal associations. Sleep complaints are almost universal in FM. There are associated polysomnogram (PSG) findings. FM patients have increased central nervous system levels of the nociceptive neuropeptide substance P (SP) and lower serotonin levels resulting in a lower pain threshold to normal stimuli. High SP and low serotonin have significant potential to affect sleep and mood. Treatment of sleep itself seems to improve, if not resolve FM. Menopausal sleep disruption can exacerbate other pre-existing sleep disorders including RLS and circadian disorders.

Abstract: The present study analyzed if the temporal change in anxiety level under the critical range of the State Trait Anxiety Inventory determines the occurrence of the first-night effect (FNE) during the sleep-onset period (SOP) in healthy adults Polysomnogram recordings were made for three consecutive nights Electroencephalograms (EEG) were scored for every 5 s into nine EEG stages Regardless of the anxiety level, the smooth process of the SOP was inhibited on the first night, which was expressed as delayed attenuation of alpha waves The FNE during the SOP occurs especially as enhanced alpha activity even when the level of anxiety is not heightened on the first-night sleep taken in unfamiliar situation

Abstract: In patients suffering from various sleep disorders and some elderly patients, sleep is disturbed with frequent but brief arousal. These events do not cause behavioral awakening, but can lead to excessive day time sleepiness. These brief arousals or microarousals (MAs) can be identified on a standard polysomnogram as a transient abrupt change of frequency, typically in the alpha and extended beta (16-40 Hz) bands. In this paper, we present a novel method to automatically detect MAs. The method is based on using the ideas of segmentation, spectral feature extraction and the identification of EEG epochs containing MA with statistical methods and decisional rules. Full-night EEG recordings from two patients are used to present some initial performance results. For this analysis, the MA events are independently scored by three experienced sleep experts. Results show the method to be promising; however, due to the large inter-scorer variations it may be necessary to tailor the detection threshold to address the varying scorer preferences (address the sensitivity/specificity tradeoffs)