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Normal and pathological hypnograms

  • Normal adult sleep
  • Graphic layout of a normal adult sleep.

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    Outline of a normal hypnogram

    Each sleep cycle lasts about 100 minutes and is made of slow wave sleep (deeper and deeper from stages 1 to 4) often related to dreaming.
    Slow wave sleep (stage 4, in blue) predominates in the start of the night whereas REM sleep (in red) becomes longer and longer in the end of the night.

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    Hypnogram of an adult

  • Normal child sleep
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    5 years old child

    The importance of slow wave sleep all over the night must be noticed.
    The first cycle is so rich in slow wave sleep that it "skips" the first REM sleep phase.
    Cf. Sleep in children

  • Insomnia in a subject who presents a normal sleep ?
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    Maintaining sleep insomnia

    The subject remains awake during 1 hour in the start of the night, and 1 hour in the end of it. He overestimates the duration of arousal during all the phases of light sleep (stage 2, in green), which punctuate the periods of REM sleep (in red) which predominates (as it is normal) in the second part of the night.
    (Note the abundance of slow deep sleep in the start of the night, and that of REM sleep in the end of the night);
    Cf. Know how to sleep

    Presence of short duration arousals, but large phases of slow deep sleep and very good quality general sleep architecture.
    Cf. Wanting to sleep
    ondes lentes chez insomniaque (Note, here, the slow waves which characterize slow deep sleep (stage 4).

  • Hypersomnia in an adult who is also a "big sleeper"
  • The presence of stage 4 (slow deep sleep) can be seen in all cycles.

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    Note the richesse in spindles (in pink) on that page of stage 2.

    Presence of plenty of slow deep sleep until the last cycle

    The visual analysis shows a correct decrease of the deepness of that slow deep sleep all over the night and the sleep cycles.

    There are neither oxygen desaturation nor micro-arousals. The subject wakes up fresh and fit but simply needs a lot of sleep.
    The excellent quality of that sleep is confirmed by the spectral analysis (Cf. Spectral analysis and final report).

  • See next article (French): Respiratory events during sleep.
  • P.S. 

    Personal iconography Dr Guilhem Pérémarty.

    Free of copyright (Copyleft) ... provided the source is mentioned.

    Auteur | Contact | Copyleft | Traductions | derniere modif 16 June 2008.