Sleep phase syndrome

Classification according to ICD-10
G47.2	Disturbances of the sleep-wake rhythm Syndrome of the delayed sleep phases Irregular sleep-wake rhythm
ICD-10 online (WHO version 2019)

The sleep phase syndrome is a chronic disorder of the right Schlafenszeitpunkte . One differentiates the delayed sleep phase syndrome , Delayed Sleep Phase Syndrome (DSPS) and Delayed Sleep Phase Disorder (DSPD) and the Pre-emptive sleep phase syndrome , Advanced sleep phase syndrome (ASPS) or Advanced Sleep Phase Disorder (ASPD) . People with DSPS tend to fall asleep later than the time they want. As a result, they have difficulty getting up at a set time to be on time at work, go to school, or participate in social life. People with ASPS, on the other hand, get tired comparatively early, but also wake up early and have difficulties falling asleep again. The latter clinical picture is relatively rare.

Formally, DSPS was first described by Elliot D. Weitzman and several others at Montefiore Medical Center. DSPS is responsible for 7–10% of all chronic sleep disorders . The deviations in the circadian rhythm present in the DSPS could be assigned to a mutation in a CRY1 gene, which is the cause of the syndrome in most of those affected. The CRY1 gene is important in the biosynthesis of cryptochromes . The mutation is inherited as an autosomal dominant trait. However, since this deviation from the norm is known only to a few doctors, it often goes untreated or is treated inappropriately.

According to the International Classification of Sleep Disorders (ICSD-2), these syndromes belong to the circadian sleep-wake rhythm disorders .

distribution

The incidence of DSPS in the general population is around 7 to 13 people affected per 10,000 people. This type is therefore the most common form of chronic circadian sleep-wake arrhythmias. The prevalence is considerably higher in adolescents and occurs in a pronounced form temporarily up to around the age of 21.

The form of ASPS occurs much less frequently in the general population, mainly middle-aged people are affected. This estimate of the prevalence shows that ASPS potentially leads to social conflicts less often and that the occurrence is therefore underestimated.

Symptoms

With ASPS, for example, those affected go to bed between six and eight in the evening, wake up early in the morning (e.g. 4 am) and can no longer fall asleep or sleep through the night. They are very tired in the evening and suffer from jobs that require attendance in the evening.

People affected by DSPS often complain that they cannot fall asleep until early in the morning, even if they woke up early in the morning. Unlike most other people with insomnia, some fall asleep at the same time each day, regardless of when they go to bed. Unless they also have another sleep disorder, they can sleep well and have a natural need for sleep. It is therefore difficult for them to get up early in the morning, since by then they have only slept a few hours. However, if they have the opportunity to sleep in according to their own sleep schedule, they sleep e.g. B. from 4 in the morning to 8 hours at noon, wake up spontaneously and are not tired again until their next required rest phase.

The prolonged waking phase and regular delay in the beginning of the main sleep phase lead to chronic sleep deprivation with a cumulative sleep deficit if the affected person is always woken up at the same time. As a result of the chronic fatigue syndrome , the person concerned suffers from depression , which is, however, a secondary result of their ongoing struggle against exhaustion or a consequence of failure at work or in school.

"Typical" period of sleep	Slightly delayed period of sleep
People with a normal sleep-wake rhythm fall asleep at a time that suits them (here: 11 p.m.) and wake up again at a suitable time (here: 7 a.m.).	People with DSPS fall asleep at a much later time (here: 2 a.m.) and wake up again later (here: 10 a.m.).

Progressive shift in the main sleep phase in a person with an endogenous circadian rhythm of 26 hours:

• 

  Fall asleep at 10 p.m. and wake up at 6 a.m. after normal sleep

• 

  Fall asleep at midnight and wake up at 8am after normal sleep

• 

  Fall asleep at 2 a.m. and wake up after a normal sleep time at 10 a.m.

• 

  Fall asleep at 4 a.m. and wake up after normal sleep at 12 p.m.

• 

  Fall asleep at 6:00 a.m. and wake up after normal sleep at 2:00 p.m.

• 

  Fall asleep at 8:00 a.m. and wake up after normal sleep at 4:00 p.m.

One study showed that people with DSPS, who are forced to adapt to the 24-hour rhythm, have a higher prevalence of comorbidities and an increased risk of dying earlier. The cause of the increased risk of illness is a disproportion between the internal physiological clock and externally prescribed times for professional and social activities.

diagnosis

To diagnose DSPS, a sleep diary (sleep log) is first used. The person concerned notes down key data on his sleep over a period of several weeks: when he goes to bed, falls asleep, wakes up and gets up, and how tired or awake he feels at the time of going to bed and getting up. Furthermore, whether and which medication is taken, whether, when and how long he slept during the day or he woke up while sleeping. Actigraphy can be used to supplement and objectify the recording of sleep-wake times .

About the polysomnography other body functions can be monitored and analyzed. The continuous measurement of body temperature can also provide important information. If the data obtained is shifted back by at least two hours compared to normal values, then DSPS is available.

In people without sleep phase syndrome, the organism can adjust to external conditions such as predetermined day and night times with its sleep-wake rhythm . The organism also adapts to the times specified by the workplace by developing its own sleep-wake rhythm. People who have to get up at 5 a.m. fall asleep at a time that is convenient for them, for example eight hours before 9 p.m. People who don't have to get up until 9 a.m., for example, get used to going to bed at 1 a.m. so that they wake up at 9 a.m. - usually without an alarm clock. If this rhythm has to be changed, for example because of a change of work place and an associated change in getting up time or because of staying in a different time zone, it usually only takes a few days for the sleep-wake rhythm to adapt to the new circumstances. In the case of a time zone change, the "transition period" is referred to as jet lag .

The human body normally adjusts to a 24-hour rhythm , so that you tire at about the same time every day and wake up at the same time the next morning. If these points in time shift by a certain range every day without any external cause, then there is a sleep-wake disorder if there is a deviation from the 24-hour rhythm .

In order for DSPS to be present, the “jet lag state”, i.e. falling asleep at a later point in time and correspondingly later awakening, must exist for a period of at least three months.

therapy

The therapy options for patients suffering from DSPS can be divided into two groups. One possibility is to adapt the patient to his " internal clock ". The second group concentrates on adjusting the internal clock to an externally prescribed daily rhythm.

If the patient wants to adapt to his DSPS, he can, for example

• Look for a job that fits your own sleep-wake rhythm or a job with free time management
• Make up for your sleep deficit by sleeping during the day

These options are not therapy in the strict sense of the word, but they do help you to live better with DSPS.

The second group of therapy options changes the sleep-wake rhythm in such a way that (mostly but only temporarily) normal getting up times are made possible. Usually a combination of the following points is used:

• Chronotherapy: The patient goes to bed three hours later each day until an appropriate time to go to bed has been reached. This new point in time must then be strictly adhered to. It should be noted that chronotherapy can possibly lead to the worse hypernycthemeral syndrome, also called non-24-hour sleep-wake rhythm syndrome. The patient's natural rhythm becomes longer than 24 hours, with the effect that the patient falls asleep a few hours later every day, which makes everyday life considerably more difficult.
• Light therapy : In the early hours of the morning, the patient isexposed toat least 2,500 lx strong light as a timer for at least one hour .
• Sleep hygiene : Strict adherence to going to bed and getting up times, improvement of sleeping conditions, avoidance of drugs such as nicotine and avoidance of blue light exposure before the desired time to fall asleep (daylight white LEDs , computer screen ).

It should be noted that the measures to adapt to a given external rhythm usually only have a temporary effect. The drug treatment z. B. with melatonin , agomelatine or vitamin B12 is currently being researched.

Web links

• Delayed Sleep Phase Syndrome (English) Information on symptoms and forms of therapy
• Delta t Association for Second Normality e. V.
• Example of a sleep log (PDF; 112 kB)
• DSPS Q&A - Circadian Sleep Disorders Network Delayed Sleep Syndrome - Questions and Answers

Individual evidence

1. ↑ ^{a b} William C. Dement : Delayed Sleep Phase Syndrome . Stanford University, 1999.
2. ^ Till Roenneberg , Martha Merrow: The internal clock. In: From Politics and Contemporary History . Issue B31, 1999, ISSN  0479-611X , pp. 11-17 ( full text ).
3. ↑ NCBI: CRY1 cryptochrome circadian regulator 1 (Homo sapiens)
4. ^ Institute of Human Genetics: Gene of the Month CRY1
5. ↑ Life Science: Are You a Night Owl? It May Be a Gene Mutation
6. ↑ Wissenschaft.de: The night owl gene .
7. ↑ Medical Life Sciences: [Gene CRY1 variant age circadian clock contributing to delayed sleep phase disorder]
8. ^ Delayed sleep phase disorder, subceptibility to DSPD.  In: Online Mendelian Inheritance in Man . (English).
9. ↑ ^{a b} S3 guideline for non-restful sleep / sleep disorders of the German Society for Sleep Research and Sleep Medicine (DGSM). In: AWMF online (as of 2009).
10. ↑ ^{a b} Parasomnias and disorders of the sleep-wake rhythm - Sleep Medicine Center Munich
11. ^ Circadian Sleep Disorders Network .
12. ^ Kristen L. Knutson, Malcom von Schantz: Associations between chronotype, morbidity and mortality in the UK Biobank cohort In: Chronobiology International The Journal of Biological and Medical Rhythm Research, 2018.
13. ↑ PowerPoint presentation on sleep disorders (slide 19 ff) - Sleep Medicine Center Munich.
14. ^ Dan A. Oren, Thomas A. Wehr: Hypernyctohemeral Syndrome after Chronotherapy for Delayed Sleep Phase Syndrome
15. ^ Oxford Academic: Sleep: Phase-Shifting Effects of Bright Morning Light as Treatment for Delayed Sleep Phase Syndrome .
16. ↑ Ergoptometry: Influences of blue light .
17. ↑ Sleep-wake rhythm disorders - Schlafgestört.de

This article is about a health issue. It is not used for self-diagnosis and does not replace a diagnosis by a doctor. Please note the information on health issues !