Sleep Study Flashcards
What is actigraphy?
motion detector
reinforces/compliments sleep diary
What is the utility of actigraphy?
objective quantification of sleep
objective assessment of sleep pattern
can be sueful for assessing larger numbers of people for sleep quantity
What is the mutliple sleep latency test?
objective measure of sleepiness
20 minute opportunities to nap every 2 hours for 5 sessions ina row
unit of measure is minutes from lights out to sleep onset
normal is >10 miuntes
pathologically sleepy is <8 minutes
REM sleep during more than one of these naps is normal
What is sleep?
defined as unconsciousness from which person can be aroused by asensory or other stimuli
contrast to coma and anesthesia which are unconsciousnessfrom which person can be aroused
What is teh function of NREM?
growth, tissue repair, clearance of wastes
enhancement of immune system
restoration of cerebral energy stores
What is the function of REM?
processing of information
unlearning irrelevant information
memory consolidation
facilitating learning and memory
What is NREM sleep properties?
includes slow-wave sleep
sometimes referred to as dreamless sleep
dreams and nightmares may occur in NREM
dreams usually not recalled
What are the properties of rem sleep?
associated with active dreaming
typically awaken in morning during an episode of REM sleep
sometimes referred to as paradoxical sleep as EEG is similar to wakefulness
What is sleep-wake cycle: effected by circadian factors and duratioon of wakefulness and sleep controlled?
homeostatic process: longer awake the greater propensity to sleep
process C: Circadian oscillatory component affecting the propensity for sleep adn waking
what is process H of sleep wake cycle?
homeostatic process; longer awake the greater propensity to sleep
What is process C of sleep wake cycle?
circadian oscillatory component affecting the propensity for sleep and waking
What are the circadian factors of sleep regulation?
internal biological clock
- -sleepy at night
- -awake during the day
approximate 24-hour period
composed of about 10,000 neurons in suprachiasmatic nucleus (SCN)
-hypothalamus
regulates endogenous biological rythms
- including sleep-wake cycle
- entrained or reset the day length by environmental photoperiod
- resetting is mediated through photoreceptors in the retina which send signals to the SCN
What is the sleep-wake model?
as time in the awake state increases, there is increased drive to sleep
What is wake-promoting factors?
Substance P corticotrophin thyrotopin - releasing factor vasoactive intestinal peptinde neurotensin epinephrine histamine glutamate cortisol serotonin
What are sleep-promoting factors?
peptides delta-sleep inducing peptide alpha-melanocyte stimulating horomone growth horomone-releasing factor gamma-aminobutyric acid cytokines, ILs prostaglandin D2 adenosine cholecystokinin, somatostatin serotonin
Wakefulness is promoted by what?
icnreased excitatory and decreased inhibitory neuromodulators and by then circadian homeostatic centers
What causes NREM sleep?
brainstem excittatory and hhypothalamic circadian and homeostatic factors decrease
Whaen does REM sleep occur?
when reduced NE and serotonin release inhibition of pontine PPT and LDT cholinergic neruons which activate the REM system
What neurotransmitters promote REM sleep?
decreased acetylcholine and dfrom decreased NE and serotonin
What neurotransmitters promote wakening?
hypothalamus leading to decreased GABA, increased histamine and increased activation of thalamus and cortex
as well as increased NE and serotonin leading to decreased acetylcholine
What neurotransmitters lead to NREM sleep?
increased GABA
decreaased histamine
decreased activation of the thalamus and cortex
What is NREM sleep signaled by in the neurons?
mean discharge rate of neurons decreased
cerebral glucose utilization decreased overall
What is REM sleep singaled by in central nervous system activation?
mean discharge rate of neurons increased in many regions
-PGO spikes
-REMs
cerebral glucose utilization increased and resembles W
cerebral blood flow greatly increased
What is the somatic acitvity of REM sleep?
- paralysis
- -postsynaptic inhibition of motoneurons
- -hyperpolarization of motoneuron membranes
- phasic
- -rapid eye movements
- -muscle twitches
What is the breathing pattern of NREM sleep?
periodic breathing noted in stage 1 and 2 but regular breathing occurs in stage 3 and 4
What is the breathing pattern in REM sleep?
electrooculogram – phasic rapid eye movments characteristic
REM sleep – irregularities in timing and amplitude of ventilatory movements rae noted
paradoxical respiration
–rib cage moves inward when abdoment moves outward
What are the ventilation changes of sleep?
significantly altered with state decrease in vent during sleep is greater than a concurrent decrease in metabolic rate PaCO2 increases sleep induced hypoventilation unique to humans among mammals
What are the hemodynamic changes of sleep?
alteration in ANS
parasympathetic activity predominates during both NREM and REM sleep
HR and CO decrease
cerebral blood flow decreases in NREM but increases in REM sleep
during phasic REM, bp and hr are unstable due to phasic vagal inhibition and sympathetic activation
overall there is a slight decrease in total vasc resistance during sleep
What are the endocrine changes of sleep?
growth horomone
-plasma conc peak 90 min after sleep onset
-higher in men than women
duration fo 1-3 hours related to SWS
-sleep deprivation suppresses GH secretion
What is parathyroid endocrine changes during sleep?
increased levels during sleep compared to awaken state
peaks between 2 and 4 am
What is the endocrine changes of adrenocorticotropic horomone?
cortisol decreases with sleep onset
cortisol levels lowest in early part of sleep, highest from 4 am to 8 am
What is the thermoregulation of NREM and REM sleep?
NREM -lowered temp set point --shivering threshold lower --sweating at normal ambient temp REM -no regulation --no shivering response --no sweating at high ambient temperature --body temperature drifts toward ambient temp
