Sleep Flashcards
What are the two forms of sleep?
Non-REM/deep
REM
What are the features of non-REM/deep sleep?
Start of night
3/4 of sleep time
Synchronised, rhythmic EEG activity, decreased cerebral blood flow
Dreams are static images
What are the features of REM sleep?
End of night
EEG shows fast activity, increased brain activity (fMRI) and increased cerebral blood flow- similar to awake
Narrative movie like dreams
Which type of sleep is more important?
Deep- if deprived them sleep will have more deep.
What does deep sleep do?
Allows the brain to switch off
What does REM sleep do?
Consolidates memories
What are the three mechanisms of sleep?
Homeostatic
Emotional
Circadian rhythmn
How does homeostasis contribute to sleep?
If tired then the body tries to sleep
How do emotions contribute to sleep?
Have to be emotionally ready for sleep- not stressed etc
How does circadian rhythm contribute to sleep?
Naturally try to fall asleep at 4am and 2pm
How does the number of hours of sleep required change as we age?
Decreases
Is sleep walking etc suggestive of underlying pathology?
No
What is insomnia?
Fitful sleep with less time than normal in REM
Does insomnia tend to suggest an underlying pathology?
Not usually
What is parasomnia?
Abnormal movements, behaviors, emotions, perceptions, and dreams
What can REM parasomnias result in?
Acting out dreams
How does the body try to protect us from parasomnias?
Sleep paralysis
What can non-REM parasomnias result in?
Sleep walking and vivid hallucinations
What is narcolepsy?
Suddenly falling asleep at inappropriate times/daytime sleepiness
What symptom can narcolepsy involve?
Cataplexy
What is cataplexy?
Sudden loss of muscle tone- generally with shock etc
How do you diagnose narcolepsy?
Clinical suspicion
Overnight polysomnography
Sleep latency test
What is a sleep latency test?
4x25 minute naps throughout the day. If they go straight into REM sleep, then pathological
