Background Limited data have suggested that sleep-disordered breathing, a condition of repeated episodes of apnea and hypopnea during sleep, is prevalent among adults. Data from the Wisconsin Sleep Cohort Study, a longitudinal study of the natural history of cardiopulmonary disorders of sleep, were used to estimate the prevalence of undiagnosed sleep-disordered breathing among adults and address its importance to the public health. Methods A random sample of 602 employed men and women 30 to 60 years old were studied by overnight polysomnography to determine the frequency of episodes of apnea and hypopnea per hour of sleep (the apnea-hypopnea score). We measured the age- and sex-specific prevalence of sleep-disordered breathing in this group using three cutoff points for the apnea-hypopnea score (≥ 5, ≥ 10, and ≥ 15); we used logistic regression to investigate risk factors. Results The estimated prevalence of sleep-disordered breathing, defined as an apnea-hypopnea score of 5 or higher, was 9 percent for w...

The Occurrence of Sleep-Disordered Breathing among Middle-Aged Adults

Objective. To assess the impact of sleep-associated gas exchange abnormalities (SAGEA) on school academic performance in children. Design. Prospective study. Setting. Urban public elementary schools. Participants. Two hundred ninety-seven first-grade children whose school performance was in the lowest 10th percentile of their class ranking. Methods. Children were screened for obstructive sleep apnea syndrome at home using a detailed parental questionnaire and a single night recording of pulse oximetry and transcutaneous partial pressure of carbon dioxide. If SAGEA was diagnosed, parents were encouraged to seek medical intervention for SAGEA. School grades of all participating children for the school year preceding and after the overnight study were obtained. Results. SAGEA was identified in 54 children (18.1%). Of these, 24 underwent surgical tonsillectomy and adenoidectomy (TR), whereas in the remaining 30 children, parents elected not to seek any therapeutic intervention (NT). Overall mean grades during the second grade increased from 2.43 ± 0.17 (SEM) to 2.87 ± 0.19 in TR, although no significant changes occurred in NT (2.44 ± 0.13 to 2.46 ± 0.15). Similarly, no academic improvements occurred in children without SAGEA. Conclusions. SAGEA is frequently present in poorly performing first-grade students in whom it adversely affects learning performance. The data suggest that a subset of children with behavioral and learning disabilities could have SAGEA and may benefit from prospective medical evaluation and treatment.

Sleep-disordered breathing and school performance in children

The electroencephalographic records from 43 subjects who slept for four consecutive nights in a laboratory environment were studied in an effort to describe the First Night Effect. These records showed that the first night of laboratory sleep contains more awake periods and less Stage I-rapid eye movement sleep. There is a delay in the onset of Stages IV and I-REM and the sleep is more changeable. These effects rapidly adapt out by the second night of sleep.

The first night effect: an EEG study of sleep.

Normal human sleep comprises two states—rapid eye movement (REM) and non–REM (NREM) sleep— that alternate cyclically across a sleep episode. State characteristics are well defined: NREM sleep includes a variably synchronous cortical electroencephalogram (EEG; including sleep spindles, Kcomplexes, and slow waves) associated with low muscle tonus and minimal psychological activity; the REM sleep EEG is desynchronized, muscles are atonic, and dreaming is typical. A nightly pattern of sleep in mature humans sleeping on a regular schedule includes several reliable characteristics: Sleep begins in NREM and progresses through deeper NREM stages (stages 2, 3, and 4 using the classic definitions, or stages N2 and N3 using the updated definitions) before the first episode of REM sleep occurs approximately 80 to 100 minutes later. Thereafter, NREM sleep and REM sleep cycle with a period of approximately 90 minutes. NREM stages 3 and 4 (or stage N3) concentrate in the early NREM cycles, and REM sleep episodes lengthen across the night. Age-related changes are also predictable: Newborn humans enter REM sleep (called active sleep) before NREM (called quiet sleep) and have a shorter sleep cycle (approximately 50 minutes); coherent sleep stages emerge as the brain matures during the first year. At birth, active sleep is approximately 50% of total sleep and declines over the first 2 years to approximately 20% to 25%. NREM sleep slow waves are not present at birth but emerge in the first 2 years. Slow-wave sleep (stages 3 and 4) decreases across adolescence by 40% from preteen years and continues a slower decline into old age, particularly in men and less so in women. REM sleep as a percentage of total sleep is approximately 20% to 25% across childhood, adolescence, adulthood, and into old age except in dementia. Other factors predictably alter sleep, such as previous sleep-wake history (e.g., homeostatic load), phase of the circadian timing system, ambient temperature, drugs, and sleep disorders. A clear appreciation of the normal characteristics of sleep provides a strong background and template for understanding clinical conditions in which “normal” characteristics are altered, as well as for interpreting certain consequences of sleep disorders. In this chapter, the normal young adult sleep pattern is described as a working baseline pattern. Normative changes due to aging and other factors are described with that background in mind. Several major sleep disorders are highlighted by their differences from the normative pattern.

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Chapter 2 - Normal Human Sleep : An Overview

Study Objectives: This study examined effects on adolescent sleep patterns, sleepiness, and circadian phase of a school transition requiring an earlier start. Design and Setting: Adolescents were evaluated in 9th and 10th grades; school start time in 9th grade was 0825 and in 10th grade was 0720. Assessments at each point included 2 weeks of actigraphy and sleep diaries at home, followed by a 22-hour laboratory evaluation, including evening saliva samples every 30 minutes in dim light for determination of dim-light salivary melatonin onset phase (DLSMO), overnight sleep monitoring, and multiple sleep latency test (MSLT). Participants: Twenty-five females and 15 males, ages 14 to 16.2 were enrolled; 32 completed the study in 9th grade and 26 completed in 10th grade. Interventions: Participants kept their own schedules, except that laboratory nights were scheduled based upon school-night sleep pattems. Measurements and Results: According to actigraphy, students woke earlier on school days in 10th than in 9th grade, but they did not go to sleep earlier and they slept less. DLSMO phase was later in 10th grade (mean = 2102) than 9th grade (mean = 2024). Sleep latency on MSLT overall was shorter in 10th (mean = 8.5 minutes) than in 9th (mean = 11. 4 minutes), particularly on the first test of the moming at 0830 (5.1 vs 10.9 minutes). Two REM episodes on MSLT occurred in 16% of participants in 10th grade; one REM episode occurred in 48%. When those with REM sleep on one or both morning MSLTs (n=11) were compared to those without morning REM, significant differences included shorter sleep latency on the first test, less slow wave sleep the night before, and later DLSMO phase in those who had morning REM. Conclusions: Early start time was associated with significant sleep deprivation and daytime sleepiness. The occurrence of REM sleep on MSLT indicates that clinicians should exercise caution in interpreting MSLT REM sleep in adolescents evaluated on their usual schedules. Psychosocial influences and changes in bioregulatory systems controlling sleep may limit teenagers' capacities to make adequate adjustments to an early school schedule.

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Adolescent Sleep Patterns, Circadian Timing, and Sleepiness at a Transition to Early School Days

Sleep patterns in late middle age males: an EEG study.

Sleep patterns in the young adult female: An EEG study

The effect of meprobamate on human sleep and dreaming was assessed in a double‐blind, placebo‐controlled study by means of all‐night electroencephalography. On nights when meprobamate was ingested in a dose of 400 mg. at 9:00 P.M. and 800 mg. at 12:00 A.M., normal subiects spent significantly less time in sleep accompanied by low‐voltage fast EEG waves and more time in sleep manifested by spindling in the EEG than when receiving placebo. The time spent in rapid eye movement periods, which are related to visual dreaming, was decreased by meprobamate. This study shows that meprobamate characteristically alters the amount of time spent in each sleep stage and significantly decreases inferred oisual dreaming. Comparisons are made between the changes in the human electroencephalogram during sleep produced by meprobamate and those produced by the barbiturates.

Robert L. Williams

Papers

The first night effect: an EEG study of sleep.

Sleep patterns in late middle age males: an EEG study.

Sleep patterns in the young adult female: An EEG study

An electroencephalographic study of the effects of meprobamate on human sleep.

The Effect of Sleep Therapy on EEG Sleep Patterns