No abstract available.
Sleep Disorders, Circadian Rhythm*

Light therapy (also called light treatment or phototherapy) involves scheduled exposure to bright artificial light. Evidence-based treatments for sleep disorders especially for circadian rhythm sleep disorders include light therapy and pharmacotherapy. In clinical practice, many of patients with sleep problems tend to impair circadian rhythmicity. Considering that light is the most potent entraining agent of circadian rhythm, careful use of light therapy can be recommended for patients with several kinds of sleep disorders. I briefly review the possible therapeutic mechanisms and clinical applications of light therapy, focusing on circadian sleep disorders.
Circadian Rhythm ; Humans ; Light ; Phototherapy ; Sleep Wake Disorders ; Sleep Wake Disorders, Circadian Rhythm

Circadian rhythm disorder is a common society issue caused by jet lag,shift work,sleep disruption and changes in food consumption. Light is the major factor affecting the circadian rhythm system. Disruption of the circadian rhythm system can cause damage to the body,leading to some diseases. Maintaining a normal circadian system is of great importance for good health. Ideal therapeutic effect can not only alleviate symptoms of the diseases,but also recovery the disturbed circadian rhythm to normal. The paper summarizes the modeling methods of animal circadian rhythm disorder,diseases of circadian rhythm abnormality,regulation of circadian clock genes and medicine which are related to circadian rhythm to diseases of circadian rhythm disorder.
Animals ; Circadian Rhythm/genetics* ; Humans ; Jet Lag Syndrome/genetics* ; Sleep ; Sleep Disorders, Circadian Rhythm

PURPOSE: The purpose of this study was to investigate sleep habits, sleep disturbance, and circadian types, and to identify factors influencing sleep disturbance in nursing students. METHODS: Participants were 140 senior nursing students. The data were collected from May 19 to 27, 2008 using self-report questionnaires. RESULTS: 1) Evening type delayed sleep-wake schedules were more frequent than for morning type, especially during weekend and evening shift duty. 2) In total sleep time, there were no significant statistical differences between morning type and evening type during weekdays, weekend, day or evening shift duty. 3) On weekdays and day shift duty, the mean score for sleep disturbance was significantly higher in the evening type compared to the morning type. 4) Sleep disturbance in weekday and day shift duty was influenced by circadian types, eating habits, and gender. CONCLUSION: The circadian types are a very important factor for determining the sleep quantity and quality in nursing students.
*Circadian Rhythm ; Female ; Humans ; Male ; Questionnaires ; Sex Factors ; *Sleep ; Sleep Disorders, Circadian Rhythm/prevention & control ; Students, Nursing/*psychology ; Young Adult

A total of 85 sleep disorders are described in the International Classification of Sleep Disorders, 2nd ed. Knowledge about those sleep disorders will be essential not only for good and healthy sleep but also for maintaining adequate physical and mental function during daytime. Sleep medicine has a relatively short history compared to other medical fields, thus, many sleep disorders are not familiar to the general public and even to physicians. In this small review about various sleep disorders, I will briefly introduce basic concepts about insomnia, sleep-related breathing disorder, hypersomnia, circadian rhythm sleep disorders, parasomnia and sleep-related movement disorders. These sleep disorders are frequently encountered in clinical settings, and understanding them will give us insight about the basic mechanism of sleep-wake states.
Classification ; Diagnosis ; Disorders of Excessive Somnolence ; Movement Disorders ; Parasomnias ; Respiration ; Sleep Wake Disorders* ; Sleep Disorders, Circadian Rhythm ; Sleep Initiation and Maintenance Disorders

Changes in core body temperature are closely related to initiation and maintenance of sleep, and are influenced by various factors such as air temperature, room temperature, clothing, human activities, and medications. These factors are closely related to sleep fragments, insomnia and other sleep disorders. Understanding the effect of the temperature related to human surroundings on the core body temperature and sleep, will be useful for understanding the physiology of sleep and to treat sleep disorders.
Body Temperature ; Circadian Rhythm ; Clothing ; Human Activities ; Humans ; Physiology ; Sleep Disorders ; Sleep Initiation and Maintenance Disorders

OBJECTIVES: It is a paradox that sleep technicians are at risk of shift work sleep disorder to help diagnose other people's sleep disorder. Until now, there have been no guidelines for scheduling shifts for sleep technicians. The purpose of this study was to survey the current shift schedule of sleep technicians. METHODS: We performed a nationwide survey of work schedules for sleep laboratories. We sent email questionnaires to sleep technicians working in university-affiliated hospitals. Information regarding starting time and duration of shift, duty on-duty off pattern for the past month, and rotation and number of sleep technicians in the sleep labs were collected. RESULTS: We received responses from 29 sleep labs. Among the 25 labs which had designated sleep technicians, three labs had night shift schedules mixed with day work on a weekly basis and the remaining 22 labs had night only shift schedule. In cases of night only shift schedules, 11 labs alternated from night shift to day shift works or vice versa every 3 months to 3 years, while the remaining 11 labs had fixed schedules without daytime rotation. Number of night shift was four or less per week, with shift durations of 9–19 hours. CONCLUSIONS: The current policies regarding scheduling shifts varied vastly depending on individual sleep labs. We found that some labs had shift schedules with long work time, quick returns, or permanent night shifts, which are generally not recommended. Further studies are needed to develop consensus guidelines for scheduling shift of sleep technicians.
Appointments and Schedules ; Consensus ; Electronic Mail ; Korea ; Sleep Disorders, Circadian Rhythm ; Sleep Wake Disorders

BACKGROUND: Although actigraphy has been used to evaluated sleep-wake patterns and quality of sleep disorders patients, its usefulness in obstructive sleep apnea syndrome (OSAS) and primary insomnia is unclear. To investigate the value of actigraphy in OSAS and differentiating OSAS from primary insomnia, night polysomnography (PSG) and actigraphy were performed simultaneously. METHODS: 31 OSAS patients and 21 primary insomnia patients were included (16 females, 36 males). Sleep latency, total sleep time, sleep efficiency and actual wake time, movement and fragmentation index (MFI) were obtained in actigraphy and compared with PSG results. Spearmann correlation analysis and Mann-Whitney U test were used. RESULTS: The sleep efficiency and total sleep time are highly correlated in PSG and actigraphy (p<0.05, p<0.01). Respiratory disturbance index and arousal index in PSG was relatively correlated with MFI in actigraphy (p<0.05). Sleep latency is not correlated in PSG and actigraphy (p>0.05). OSAS had a significantly higher movement and fragmentation index (MFI) than that of primary insomnia (p<0.05) CONCLUSIONS: Actigraphy is a useful and convenient test in differentiating OSAS from insomnia as well as sleep-wake cycle disorders.
Actigraphy* ; Arousal ; Female ; Humans ; Polysomnography* ; Sleep Apnea, Obstructive* ; Sleep Wake Disorders* ; Sleep Disorders, Circadian Rhythm ; Sleep Initiation and Maintenance Disorders*

Excessive daytime sleepiness in childhood might be abnormal phenomenon and often related to the sleep disorders or insufficient sleep duration. The most common cause of excessive daytime sleepiness would be insufficient sleep. However, narcolepsy, idiopathic hypersomnia, circadian rhythm sleep disorders, medication, medical illness and other sleep disorders that could cause insomnia and poor quality of sleep also result in excessive daytime sleepiness. The misdiagnosed and untreated excessive daytime sleepiness in childhood can lead to serious developmental and educational problem.
Child ; Humans ; Hypersomnolence, Idiopathic ; Narcolepsy ; Sleep Wake Disorders ; Sleep Wake Disorders, Circadian Rhythm ; Sleep Initiation and Maintenance Disorders

OBJECTIVES: Delayed sleep phase syndrome (DSPS) is characterized by difficulties in falling asleep and waking up at a desired time. Dawn simulation is a technique using a light that gradually increases in intensity before awakening in the morning, to imitate a natural sunrise. It has been found to be effective in decreasing both morning drowsiness and difficulty in awakening as well as treating symptoms of seasonal affective disorder. The aim of this study was to determine whether dawn simulation is helpful in decreasing difficulty in morning awakening and daytime sleepiness in adolescents with DSPS. METHODS: Twelve adolescents with DSPS participated in a 2-week dawn simulation trial. Each subject self-assessed level of difficulty in awakening, morning drowsiness and daytime sleepiness during a 2-week baseline period and a following 2-week trial period with dawn simulator. Subjects used Stanford Sleepiness Scale (SSS) for measuring morning drowsiness and Epworth Sleepiness Scale (ESS) for measuring daytime sleepiness. Difficulty in awakening was assessed by a single-item questionnaire. RESULTS: Dawn simulation trial decreased morning drowsiness (p=0.016) and daytime sleepiness (p=0.013) significantly compared to baseline. It also seemed to improve difficulty in awakening, but the effect was not statistically significant (p=0.092). CONCLUSION: Dawn simulation may help waking up in the morning and may improve daytime functioning by deceasing both morning drowsiness and daytime sleepiness in adolescents with DSPS.
Adolescent* ; Humans ; Surveys and Questionnaires ; Seasonal Affective Disorder ; Sleep Disorders, Circadian Rhythm* ; Sleep Stages