Hypnogram

A sleep profile (also called " hypnogram " ) is in Sleep Research and Sleep Medicine is a graphical representation of the reached in the course of sleep stages of sleep.

The sleep profile is one of the results of an evaluation carried out by means of a polysomnography study and used the evaluation of sleep in the diagnosis of sleep disorders. This representation makes features such as the deviation from normal sleep cycle in sequence and duration significantly and thus gives indications of possible diseases.

Content of the diagram

The x- axis of the graph indicates the time and the y -axis shows the stages of sleep again. Sleep stages are by derivation of electroencephalography (EEG ), electrooculography ( EOG) and electromyography ( EMG) determined in a polysomnographic examination.

The naming of the sleep stages follows the subdivision of sleep in the two forms of REM sleep and non-REM sleep ( NREM sleep also called ). REM sleep is referred to as " sleep stage R". The NREM sleep is referred to as " sleep stage N" and further subdivided into two stages N1, N2 and N3. The term " stage W" stands in hypnogram for the waking state.

This nomenclature and the comprehensive set of rules for the classification of sleep stages go back to a publication of the American Academy of Sleep Medicine in 2007.

An earlier nomenclature goes back to a publication by Allan Rechtschaffen and Anthony Kales in 1968. There, the NREM sleep was divided into 4 stages, 2 light sleep stages (I and II ) and 2 deep sleep stages (III and IV). The two deep sleep stages are now combined as stage N3 sleep.

Polysomnography

Studies using polysomnography be performed in a suitably equipped sleep laboratory and are associated with high cost. The patient has to spend in the sleep laboratory at least one night, and the time for preparation and follow. In addition to the sleep laboratory facilities and personnel on the technology used for monitoring the measurement is required. Cases in which the polysomnography and thus sleep profiles for adequate differential diagnosis with regard to the complaint of "not restful sleep " are required to be listed in the guideline " non -restorative sleep / sleep disorders ."

Polysomnography is also used in the investigations of multiple sleep latency test ( MSLT ) and multiple wake live test (MWT ) are used.