1. Normal sleep stage แพทย์หญิง กาญจนา พิทักษ์วัฒนานนท์
อายุรแพทย์ผู้เชี่ยวชาญระบบประสาท
แพทย์ประจำศูนย์สมอง โรงพยาบาลสมิติเวชศรีราชา

2. Why sleep ? Brain development Memory / cognition / long term potential
Immunity
Conservation energy
Repair & Restoration

3. Sleep hygiene Regular sleep time Proper sleep environment
Stimulation control
Avoidance of time in bed worrying
Avoidance of poorly timed alcohol and caffeine
Regular exercise but not within 3 hours of bedtime
Wind-down time
Late-night high-tryptophan snack

4. Circadian clock
Human circadian clock generates a rhythm slightly longer than 24 hours when it has no external cue to set it.
Most people can adjust to 23- or 25- hour day but not to a 22- or 28- hour day.
Bright light late in the day can lengthen the circadian rhythm.

5. Duration of sleep Circadian rhythm Circadian clock Zeitgeber
Circannual rhythm
The purpose of the circadian rhythm is to keep our internal workings in phase with the outside world.
Light is critical for periodically resetting our circadian rhythms.
A zeitgeber is a term used to describe any stimulus that resets the circadian rhythms.
Exercise, noise, meals, and temperature are others zeitgebers.

6. Light & sleep : suprachiasmatic nucleus

7. SCN Mechanisms of the circadian rhythms include the following:
The Suprachiasmatic nucleus.
Genes that produce certain proteins.
Melatonin levels.

8. Biological clock Physiological pathway of the biological clock:
Light levels  retina
 suprachiasmatic nucleus of hypothalamus
 pineal gland  secretion of melatonin

9. The suprachiasmatic nucleus (SCN) is part of the hypothalamus and the main control center of the circadian rhythms of sleep and temperature.

10. Biological clock

11. Go East : Phase advance

12. Electroencephalographic rhythms

13. Brain waves

15. Brain waves : frequency
Hz - depression
Hz - wakeful dreaming, vivid images
4-8 Hz - dreaming sleep,
deep meditation,
subconscious mind
Hz - relaxation
5.8 Hz - dizziness
7 Hz - increased reaction time
Hz - induces sleep, tingling sensations
Hz - increased mental ability
18 Hz - significant improvements in memory
55 Hz - Tantric yoga

16. Benefit of meditation
Meditation = practices that train attention to heighten awareness and bring mental processes under greater voluntary control
Yoga, Zen, transcendental meditation (TM)
Potential physiological benefits
Similar to effective relaxation procedures

17. Polysomnography : PSG EEG ( electro-encephalography )
EOG ( electro-oculograms )
Chin EMG ( electro-myograms )
Left & Right anterior tibialis EMG
Intercostal EMG
ECG ( electro-cardiogram )
Pulse oximetry ( oxygen saturation )
Nasal & Oral thermistors ( airflow )
Chest & Abdominal strain guages

18. Polysomnography : PSG

20. Sleep cycle / Hypnogram

21. Awake
EEG: - rhythmic alpha waves (8-12Hz) // only if the eyes are closed
- beta waves (20-30Hz)
EOG: - eye movement (observation process)
EMG: - continual tonically activity of muscles

22. Sleep stage I : NREM I Loss of eye blink Attenuation of Alpha rhythm
Slow rolling eye movements
Fronto central Theta activity
Increased Beta activity
Vertex waves

23. NREM1 sleep EEG: - the absence of alpha activity - Vertex sharp waves
EOG: - slow eye movement
EMG: - relatively lower amplitude

24. Sleep stage II : NREM II Sleep spindles K complexes Vertex waves
Brief , 12 – 16 Hz , synchronous bursts of activity , usually maximal in the central , or less commonly frontal , regions
K complexes
Often accompany sleep spindles . A sharp negative wave followed by a high-voltage slower wave
Vertex waves
Named for tendency to phase reverse in central regions.
Sharp waves
May occur in trains
K complexs & Vertex waves may result from brief sleep disturbances

25. NREM2 sleep
EEG: - sleep spindles (oscillating with the frequency between Hz)
- K-complexes (high voltage, sharp rising and sharp falling wave)
- relatively low voltage mixed frequency
EOG: - the absence eye movements
EMG: - constant tonic activity

26. Sleep stage III : NREM III
> 20 % but < 50 % of the background rhythm is Delta activity

27. NREM3 sleep EEG: - consists of high-voltage (>=75uV)
- slow delta activity (<=2 Hz) // electrodes Fpz-Cz or Pz-Oz
EOG: - the absence eye movement
- delta waves from EEG
EMG: - low tonic activities

28. Sleep stage IV : NREM IV
> 50% of the background rhythm is Delta activity

29. REM sleep Bursts of rapid eye movement Loss of muscle activity
“ Desynchronization ” of the background rhythm.
The predominant delta rhythm of slow wave ( stage III & IV ) sleep is replaced by faster frequency ( beta and theta ) rhythms normally seen during the wakeful state.
Sawtooth waves

30. REM sleep EEG: - relatively low voltage - mixed frequency
EOG: - contains rapid eye movements
EMG: - tonically suppressed (Sleep Paralysis)

31. Hypnogram / Sleep cycle

32. Brain development : REM

33. Dream : REM

34. Why dream ?

35. Sleep disorder Insomnia – difficulty falling or staying asleep
Narcolepsy – falling asleep uncontrollably
Sleep Apnea – reflexive gasping for air that awakens
Nightmares – anxiety arousing dreams – REM
Night Terrors – intense arousal and panic – NREM
Somnambulism – sleepwalking

36. Sleep disorder