Sleep and Sleep Disorders

Abstract

eye movement (REM) and nonrapid eye movement (NREM). NREM sleep is further subdivided into sleep stages 1 through 4, which represent a continuum from light sleep (stage 1) to deep sleep (stages 3 and 4). REM sleep is characterized by rapid eye movements similar to those seen in the waking state, as well as muscle atonia.Healthy human individuals show stable and distinct patterns of sleep architecture, that is, the cyclic alternations of the different sleep stages. Sleep is entered through the transitional stage 1, and followed by stages 2, 3, and 4, respectively. After about 90 min, through stage 2 sleep, REM sleep begins. The first appearance of REM sleep during the night is termed REM latency. This 90-to 100-min cycle repeats itself typically four to five times during the night. However, the internal temporal structure changes, so that at the beginning of the night stages 3 and 4 are long while REM sleep is short, and as the night progresses, the amount of stages 3 and 4 decreases, while the amount of REM sleep increases.Both REM sleep and non-REM sleep stages 3 and 4 are homeostatically driven; that is, selective deprivation of each of these states subsequently causes a rebound in their appearance once the person is allowed to sleep. This finding leads to the ubiquitous assumption that both are essential in the sleep process and its many functions. 3 REM sleep may also be driven by a circadian oscillator, as studies have shown that REM is temporally coupled with the circadian rhythm of temperature. 4Because the prevalence of several medical and psychiatric conditions that affect sleep, as well as the prevalence of specific sleep disorders, is high in the elderly population, it is extremely difficult to portray the picture of the "normal" elderly sleeper. Nevertheless, studies of agerelated changes in sleep architecture have found some common characteristics. Sleep efficiency, defined as the The prevalence of sleep complaints increases dramatically with age and is estimated to be about 40% in the elderly population. 1 These complaints include difficulty falling asleep, waking up at night, waking up too early in the morning, not feeling well rested, and needing to nap during the day. In an epidemiologic study of more than 9000 participants aged 65 and over, more than half reported at least one sleep complaint occurring most of the time. 2 Women were more likely to report nighttime complaints but were less likely to nap during the day compared to men. The most common complaint was waking up at night (30%), followed by daytime naps (25%) and difficulty falling asleep (19%). Less than 20% reported rarely or never having any sleep complaint. Sleep complaints were associated with coexisting health disorders, including poor self-perceived health, depressive symptoms, respiratory symptoms, physical disabilities, chronic medical conditions, and medication use. However, of the healthy minority in this study, over one-fourth reported at least one chronic sleep complaint.Although age-related changes do occur in normal slee...

International Perspectives: Varying International Approaches to Prevention of Neonatal Early-Onset Group B Streptococcal Disease

“…The data shown in the Figure demonstrate clearly that although different national policies were in place, both the United States and Israel experienced a modest but consistent fall in EOGBSD, reaching 2012 with approximately 0.25 cases per 1,000 live births. (13) To explain the similar rates despite different policies, the possibility of widespread "off-label" screening for GBS among Israeli women was proposed. It was thought possible that social pressures and Internet exposure may be influential.…”