sleep medicine 1, 2, 3 Flashcards
define what sleep is
distinct neurological state when organisms are unaware of its surroundings
what are the two signs to show animals are sleeping
dropping abdomen and drooping antennae
what are the three distinct states of brain activity
- wakefullness
- slow wave sleep NREM
- REM sleep also called paradoxical
what is the characterisation of slow wave sleep
the brain is tuned down and eyes are shut, unaware of our surroundings. the motor system is awake
what distinct stage of sleep do most parasomnias occur in
NREM
what happens during REM seep
the cortex is same activity as when awake but we are not aware of our surroundings, if you awake during REM you can report dreams.
what stage of sleep are you paralysed
REM
why are you paralysed in REM sleep
inhibition of the descending alpha motor neurones
what is lucid dreaming
halfway between REM and wakefulness
what is sleep paralysis
wake up from REM unable to move, paralysis is still present and motor system is not in wakefulness yet
slow-wave sleep has what amplitude
high amplitude
what are the four stages of NREM sleep
- drowsiness
- light sleep
- deeper sleep
- deepest sleep
what stage of NREM sleep is the first proper stage of sleep
light sleep (2)
why is NREM sleep low frequency with high amplitude
because the cells are synchronised cell firing
why is REM sleep high frequency with low amplitude
because the cells are desynchronised cell firing
How can you tell if someone is in REM sleep?
rapid eye movements
what is skeletal muscle paralysis caused by
inhibition of descending alpha Motor neurones
is sleep voluntary or involuntary
voluntary because we decide when to sleep. However, extreme sleep deprivation sleep is then involuntary
what is the 3 process system that makes us sleep
- homeostatic
- circadian
- ultradian
what is sleep propensity
the pressure to sleep
why do we wake up?
due to decrease homeostatic and circadian pressure
what prevents the body from recouping from missed sleep
body clock
how many hours on average do we spend in REM sleep
1-2 hours
how many hours on average do we spend in light sleep
2
what can sleep disorders be categorised by
- disorders of initiating and maintaining sleep DIMS
- disorders of excessive sleepiness DOES
- parasomnias
- circadian rhythm disturbances
what are the two categories of DIMS
acute or chronic
what are examples of DIMS
insomnia, depression, poor sleep hygiene, drug induced, fatal familial insomnia
what is fatal familial insomnia
very rare inherited condition, related to mad cow disease. Develops insomnia in teens and then die by mid 20’s
what are examples of things that cause poor sleep hygiene
phones, tv, electronic distractions
what are the examples of primary DOES
narcolepsy, cerebral injury, idiopathic hypersomnolence
primary DOES are related too
related to brain disorders
what is idiopathic hypersomnolence
naturally sleep people
what is narcolepsy
an autoimmune disorder that causes a lack of orexin producing cells. this causes switches from REM to NREM = disrupted sleep
what are the four main symptoms of narcolepsy
- irresistible sleepiness
- cataplexy
- hypnagogic hallucinations
- sleep paralysis
what is cataplexy
motor inhibition of REM sleep, the patient is completely awake but there is sudden muscle weakness
what are examples of secondary DOES
- obstructive sleep apnoea
- central sleep apnoea
- limb movement disorders
obstructive sleep apnoea can cause
hypertension, MI, stroke, diabetes
how does a person with obstructive sleep apnoea wake up
person struggles to breath, rising Co2 and lowering O2 causes the person to wake up
what is bruxism
a type of parasomnia, teeth grinding
what are examples of circadian rhythm disorders
- delayed sleep phase syndrome
- advanced sleep phase syndrome
- non-entrained circadian rhythm
all teenagers experience what type of circadian rhythm disorder
delayed sleep phase syndrome
what type of circadian rhythm disorder do the elderly experience
advanced sleep phase syndrome
what do we look at when assessing sleep
duration, quality, architecture, associated phenomena
how can we assess sleep duration
- sleep dairy
- actigraphy
- polysomnography
limitations with sleep diaries
moderately objective, sleep often underestimated
what is actigraphy
recording of movement when someone is sleeping, prolonged for around 6 weeks
movement = wakeful
little movement = sedated
no movement = sleep
what is polysmnography
recording of physiological variables: EEG, EOG, EMG, ECG and body movement
how can you record respiratory polysomnography
chest wall movement
air flow
airway pressures
how can you record cardiovascular polysomnography
heart rate, heart variability, blood pressure
how to assess wakefulness
questionnaires, multiple sleep latency, multiple wakefulness, vigilance testing
what is the Epworth sleepiness scale
likelihood of falling asleep in 8 common situations
normal people: 2-10
insomnia : 0-6
narcolepsy: 13-23
what are examples of combination tests for assessment of sleep
Berlin sleep apnoea questionnaire
Pittsburgh sleep quality index
