This exercise summarizes the basic brain processes in sleep and the use of the EEG (electroencephalogram; "brain waves") to measure sleep stages. It includes the following topics: ! sleep as an active process and brain areas that turn it on ! the EEG: how it is recorded and what it shows about brain activity ! the EEG for the two basic kinds of sleep, slow wave sleep (SWS) and rapid eye movemen...

BACKGROUND We examined the effects of the various sleep stages on RR and QT intervals in healthy subjects and tested the hypothesis that there is a differential effect of sleep stage on QT interval in women compared with men. METHODS AND RESULTS Eighteen healthy subjects (9 women, age 22 to 45 years) underwent polysomnography and simultaneous recording of ECG, blood pressure, and respiration....

OBJECTIVE The stage of sleep is a known modulator of high-frequency oscillations (HFOs). For instance, high amplitude slow waves during NREM sleep and the subtypes of REM sleep were shown to contribute to a better separation between physiological and pathological HFOs. This study investigated rates and spatial spread of the different HFO types (physiological and pathological ripples in the 80-2...

Sleep quality is important, especially given the considerable number of sleep-related pathologies. The distribution of sleep stages is a highly effective and objective way of quantifying sleep quality. As a standard multi-channel recording used in the study of sleep, polysomnography (PSG) is a widely used diagnostic scheme in sleep medicine. However, the standard process of sleep clinical test,...

Objective: The nasal cycle, which is present in a significant number of people, is an ultradian side-to-side rhythm of nasal engorgement associated with cyclic autonomic activity. We studied the nasal cycle during REM/non-REM sleep stages and examined the potentially confounding influence of body position on lateralized nasal airflow. Methods: Left- and right-side nasal airflow was measured i...

STUDY OBJECTIVES It has long been suspected that sleep is important for regulating body temperature and metabolic-rate. Hibernation, a state of acute hypothermia and reduced metabolic-rate, offers a promising system for investigating those relationships. Prior studies in hibernating ground squirrels report that, although sleep occurs during hibernation, it manifests only as non-REM sleep, and o...

BACKGROUND Insomnia is the most common sleep disorder. Treatment options are improved sleep hygiene, relaxation, cognitive behavioral therapy, and medications. Studies examining the effect of hypnotics on insomnia reported that placebo had a substantial beneficial effect. OBJECTIVES To evaluate whether placebo is an effective treatment for insomnia. METHODS We assessed 25 patients with inso...

We examined the effects of sleep microstructure, ie, the cyclic alternating pattern (CAP), on heart rate (HR)- and blood pressure (BP)-regulating mechanisms and on baroreflex control of HR in healthy humans and tested the hypothesis that sympathetic activation occurring in CAP epochs during non-rapid eye movement (non-REM) sleep periods is buffered by the arterial baroreflex. Ten healthy males ...

OBJECTIVE To assess the effect of passive body heating on the sleep patterns of patients with fibromyalgia. METHODS Six menopausal women diagnosed with fibromyalgia according to the criteria determined by the American College of Rheumatology were included. All women underwent passive immersion in a warm bath at a temperature of 36 ±1 °C for 15 sessions of 30 minutes each over a period of thre...