Sleep Disorders Flashcards
define sleep
normal, reversible, recurring state with loss of ability to respond to the external environment
two types of sleep
- non-REM sleep
2. REM sleep
describe non-REM sleep
start of the night
synchronised, rhythmic EEG activity, partial muscle relaxation, reduced cerebral blood flow
reduced HR, BP and TV
essential sleep to allow cortex to recover
describe REM sleep
end of the night
EEG shows fast activity and increased brain activity
atonic muscles (except diaphragm and extraocular muscles)
low cerebral blood flow
impaired thermal regulation
narrative dreaming
what is the circadian rhythm important for?
sleep-wake appetite body temperature alertness hormone levels (cortisol) lasts around 25 hours
what re-sets circadian rhythm?
ganglion cells when they receive light
examples of disorders of sleep
- parasomnias
- narcolepsy
- insomnia
two types of parasomnias
- non-REM= first 2/3rd of night, waking longer
2. REM= last 1/3rd of night, dream interactions
what is parasomnia?
unusual activities around sleep
define narcolepsy
seized by sleepiness (somnolence)
peak onset of narcolepsy
aged 15
aged 36
presentation of narcolepsy
daytime sleepiness (during eating/talking)
cataplexy
hypnagogic hallucinations (occur at sleep onset)
sleep paralysis
RBD (REM sleep behaviour disorder e.g. parasomnia)
define cataplexy
loss of muscle tone often triggered by emotion (DANGEROUS)
what is sleep paralysis?
unable to move when falling asleep or awaking with retained consciousness
diagnosis of narcolepsy
overnight polysomnography
multiple sleep latency test
lumbar puncture (for low hypocretin- hormone associated with sleep, arousal, etc.)
