ENN-ICS offers 12 courses:
1. Basics of chronobiology (Please note: This course is offered as a free trial course to the public!)
2. Sleep physiology
3. The international classification of sleep disorders
4. Insomnia
5. Sleep related breathing disorders
6. Hypersomnia
7. Circadian rhythm sleep disorders
8. Parasomnias
9. Sleep related movement disorders
10. Sleep laboratory
11. Sleep hygiene
12. Sleep in children
In preparation:
Narcolepsy
Sleep in the Elderly
The eLearning methodology is necessary for presenting the eLearning materials in an effective and pedagogical way. Within the document "eLearning methodology" we will explain the answer of the question:
Short descriptions of the courses:
Biological rhythms are observed in most living beings (plants and animals), ie, functions repeat at regular intervals or periods. Each biological rhythms has a specific period; those with a 24hour period are called circadian. The Sleep-wake cycle is a circadian rhythm found in most animals and humans. Within the 24 hour rhythm, sleep is held during the night for many animals and humans. Circadian rhythmicity is regulated by cells located in the suprachiasmatic nuclei in the hypothalamus, which work as an internal clock. The 24 h rhythm is very stable and regulates other rhythms, the activity, performance, endocrine and immunologic functions. Furthermore Sleep as an organized physiological state with its own structure is restricted to almost all mammals. Also the autonomous functions such as heart rate, respiration and blood pressure regulation are modulated by the circadian rhythm. Shift work may disturb the circadian rhythm. Transmeridian flights also require an adaptation of the circadian rhythm to the new 24-hour rhythm at the other location.
Sleep functions are not yet well determined. Sleep is essential for survival in most animals and several facts suggest that it is essential for memory consolidation, and for hormonal, thermic and immunologic homeosthasis. Sleep is not just the absence of activity but has an internal structure with light sleep, deep sleep and rapid eye movement (REM) sleep. Deep sleep is related to physical restoration with anabolysing hormone production (growth hormone and prolactine) directly coupled to it and to brain restoration in consequence of the marked slowing of brain activity. REM sleep is related to mental and psychological balance with dreaming associated mostly to it. Although there is also some dreaming during the other, the so-called non-REM sleep stages, more vivid dreams occur during REM sleep. The sleep stages occur during sleep following a well organized temporal sequence, called sleep cycle. A sleep cycle has a duration of 90 to 110 minutes and it starts with light sleep followed by deep sleep and then REM sleep; 4 to 5 cycles occur during the night sleep.
The autonomous nervous system with heart rate, blood pressure, respiration and intestine functions changes with the sleep stages, especially with the changes of REM and non-REM sleep. During REM sleep a high variability of all functions is observed making it more sensible to disturbances and possible disorders
Sleep disorders express themselves by the complaints of either sleeplessness which is called insomnia or being excessive sleepy which is called hypersomnia. The complaints may be caused by stress, environmental factors, by organic or psychiatric disorders or by disturbances of the sleep-wake system itself. A systematic classification of sleep disorders had been developed and we can distinguish more than 80 different sleep disorders. The sleep disorders are classified into insomnia, hypersomnia, sleep related breathing disorders, sleep related movement disorders, parasomnias, circadian rhythm sleep disorders, normal variants and other sleep disorders.
The complaint of insomnia is very common. Often insomnia is caused by stress, environmental discomfort or other organic or mental disorders. Some types of insomnia are however intrinsic sleep disorders. Sleep state misperception is a disorder where the subject thinks it does not sleep but actually there is enough sleep. Psychophysiological insomnia requires help by a sleep specialist. Most types of insomnia can be diagnosed by sleep experts with very specific questions and interviews. Sleep diaries and careful sleep logs may also help in the diagnosis of sleep disorders. Only in few cases a sleep laboratory investigation is need and can give reveal the ultimate diagnosis. Traditionally insomnia is treated by behaviour therapy, sleep hygiene rules and medication (hypnotics, antidepressives and sedatives). These medications may help to open a helpless cycle in cases of severe insomnia but a training of changed behavior causes more persistent help to insomnia.
Sleep related breathing disorders are very common. Obstructive sleep apnea is the most common form of sleep related breathing disorders with a prevalence of 2% in women and 4% in men. Other forms are central sleep apnea and a number of different hypoventilation syndromes found in patients with congestive heart failure. An apnea is a cessation of airflow for 10sec or more; apnea index is abnormal when there are more then 5 apnea per hour. Apneas are often associated with oxygen desaturations. Apneas lead to unrestorative sleep, to severe loss of oxygen and to cardiovascular disturbances. Patients suffer from excessive daytime sleepiness. As a consequence they have an increased risk for car accidents due to sleepiness. They also have an increased risk to develop cardiovascular disorders such as arterial hypertension, cardiac ischemia with myocardial infarction, and stroke. The therapy of choice is non-invasive ventilation using nasal continuous airway pressure nCPAP. This therapy reveals all symptoms and reduces the risk for cardiovascular disorders substantially. Weight loss and alcoholic beverages abstention are also extremely important. ENT or mandibular surgical interventions together with techniques of mandibular advancement should be considered in certain cases.
Hypersomnia with the complaint of excessive sleepiness during daytime can be caused by sleep related breathing disorders or sleep related movement disorders or by other causes. The first two groups are explained in separate chapters. Among these other causes narcolepsy with and without cataplexy is the most important diagnosis. Narcolepsy is a rare sleep disorder with sudden sleep attacks during daytime and with a very disturbed sleep at night. When affected patients have a sleep attack they are unable to stay awake. In the narcolepsy with cataplexy the catapletic attacks are initiated by emotions such as jokes or anger and consist of a sudden muscle atonia, so that patients may fall; atonia has a cranio-caudal progression afecting first the eyelids, masseters and neck muscles. Sleep is no longer restful. In a polysomnography it is found that sleep onset starts with REM sleep. Furthermore for the diagnosis a multiple sleep latency test should be performed. The pathophysiology involves a disturbed orexin hypocretin secretion, which shows very low levels at the spinal fluid. There is a genetic predisposition for narcolepsy. Medical drugs can help to lower the symptoms.
Circadian rhythm sleep disorders are often found in persons working at night shift. Transmeridian flights cause sleep wake problems caused by a disturbance of the circadian rhythm. There are intrinsec disturbances of the circadian rhythm, namely the delayed sleep phase disorder, advanced sleep phase disorder or the irregular sleep wake cycle. These disorders in consequence cause lots of problems in social interaction. Behavioral consultation is the best therapy in these cases. The use of enforced zeitgebers such as light therapy, physical exercise during daytime and other sleep hygiene recommendations can help to overcome the problems caused by circadian rhythm sleep disorders. Melatonin is required in certain cases.
In parasomnias, abnormal motor and autonomous activation occurs during sleep. Arousal disorders present a big group among the parasomnias, together with those related to NREM or to REM sleep. Sleep walking, REM sleep behavior disorders are other parasomnias. The origin of most parasomnias is still unknown. Stress, other disorders and some pharmaceuticals can contribute to the development of parasomnias. In some parasomnias pharmaceutical can help to lower the symptoms. Usually preventive actions are important and can help to deal with these problems.
The sleep related movement disorders manifest themselves most often with hypersomnia. Due to the awakenings caused by the movements, some patients also complain of insomnia. In these disorders movements of the limbs are observed. In some patients these movements occur only during sleep, the periodic limb movement syndrome and in other patients the movements are also found during daytime, the restless legs syndrome. There are other movement disorders, such as the Parkinson syndrome, which also show sleep disturbances as an accompanying feature. Sleep related movement disorders need a diagnosis in a sleep laboratory with a cardiorespiratory polysomnography in order to quantify and to detect the origin of the movements of the limbs. Different types of pharmaceutical treatment can help to relief the symptoms.
The sleep laboratory performs investigations which should be selected according to the specific problem to be solved. Sleep recordings are done by the use of cardiorespiratory polysomnography. This investigation consist of a recording of the electroencephalogram (EEG), electrooculogram (EOG) and electromyogram (EMG) in order to determine sleep stages. Based on the recorded patterns it is possible to detect wakefulness, light sleep, deep sleep and REM sleep (rapid eye movement sleep). In addition respiration is recorded using airflow and respiratory effort sensors to detect breathing disorders. The electrocardiogram (ECG) is recorded in order to detect cardiac arrhythmias during the night. EMG of the legs is recorded to detect movement disorders. Not only sleep recording is performed at a sleep laboratory. Also daytime recordings are done in order to diagnose sleepiness at day. The corresponding tests are the multiple sleep latency test (MSLT) and the maintenance of wakefulness test (MWT). Ambulatory sleep recording is another option to diagnose sleep disorders at home in the normal sleeping environment. Furthermore OSLER test and actigraphy can also be performed. Rules and recommended procedures for each type of recordings are described together with the most suitable processing techniques.
In order to achieve a restorative sleep, sleep hygiene must be followed. Behavioral, environmental conditions as well as drugs and substances influence sleep very much. Regular sleep wake schedules, moderate activity in the evening, regular sleep routines are useful. The bed should be used for sleep and sex only. Excessive meals and smoking in the evening disturb sleep. Light, noise and inappropriate temperature at night do disturb sleep. Many drugs and substances influence sleep such as alcohol, nicotine, medical stimulating drugs, other drugs and all these should be avoided.
Sleep develops with age. In the first months children sleep up 16 hours. In contrast to adults sleep is organized in active and quiet sleep. Wakefulness can be differentiated in active and quiet wakefulness. After 3 months sleep occurs predominantly during night time and is slowly reduced in total duration. Also non-REM sleep and REM sleep can be distinguished. After 6 months sleep duration is reduced further. After 3 years there is less frequent daytime napping. At the age of 6 years normal sleep structure is achieved with much deep sleep in the beginning. At adolescence there is again a need for longer sleep which is often not taken and thus leads to sleep deprivation. Sleep disorders in children may have specific features and symptoms. Parasomnias are frequently observed during childhood and they tend to disappear when getting older.
Created: ENN-ICS consortium
Date:
2006-03-08
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