Vosko Michels CIS Flashcards
major differences between NREM and REM sleep
REM– Even more Decreased postural muscle tone***
NREM (SWS) Increased arousal thresholds Decreased thermoregulation Decreased postural muscle tone 4 stages Synchronous EEG 75% of Total Sleep Time Prominent in early phases of sleep
REM (PS) Increased arousal thresholds Decreased thermoregulation Decreased postural muscle tone Rapid Eye Movements Vivid recall of dreams Asynchronous EEG 25% of Total Sleep Time Prominent in later phases of sleep
Benzodiazepines
suppress NREM sleep
(Valium)
*Most sedative hypnotics are benzodiazepines (GABA-ergic agonists)
Anti-depressants
suppress REM sleep
(Fluoxetine): Prozac Eyes
Withdrawal from drug causes
rebound of the sleep it normally suppresses
Process S
homeostatic control of sleep
things like adenosine build up in the brain and cause even more fatigue
Process C
circadian control of sleep
main one: cortisol (cortisol spike in the morning)
circadian misalignments occur with genetics, shift work, jet lag, etc.
Featues of sleep stages
Stage 1- transition phase. Low amplitude, high frequency. Occasional slow waves getting in.
Stage 2- K complexes- large deflections with sawtooth shape,
Sleep spindles- low amplitude blurbs
MOST of our sleep here
Stage 3- transitioning into stage 4, more delta waves
Stage 4- mostly delta waves. Number of delta waves is indicative of level of sleep deprivation.
Polysomnography
EOG- oculograms.
chest and abdomen movement tell you how much effort is going into the breathing
chin muscle tone is cyclic in stage 1, drops dramatically to stage 3 and 4.
when are you better at regulating your autonomics?
NREM, as opposed to REM sleep
eye movments characteristic of REM movements? Other clues?
opposing wave directions between R and L eye
going with no muscle tone in the chin, definitely tells you REM.
EEG waves should look a lot like being awake.
Heart rate can be increasing.
With obstructive sleep apnea, which phase of sleep is most disrupted? Why?
REM
autonomics aren’t as well controlled, postural muscles lose tone but are also serving as respiratory muscles in sleep apnea
If there is respiratory distress of any origin, it will likely first show up
during sleep. REM is the most sensitive period in sleep to show any respiratory dysfunction.
56 y/o Male Extreme Daytime Fatigue Awakens every 10 minutes during sleep Takes triazolam (Halcion) before bed Slurred Speech
Start with what?
Start with Epworth sleep scale.
clue that you can rule out insomnia is the sleeping pill doesn’t help. To surely rule it out you need a sleep lab study.
parasomnia- usually you think you’re sleeping, other people complain of your behaviors
sleep disordered breathing- need a sleep lab. Epidemiology can help- obesity, bed partner complaining of snoring
Both wake and sleep are coordinated by
specific brainstem and hypothalamic nuclei
Brainstem nuclei promote excitatory tonic input to motor neurons during wakefulness. Provides “muscle tone”
Definition and Epidemiology of OSA
Definition
Usually defined as 15 or more apneic events per hour of sleep lasted a duration of 10 s or more
Obstruction occurs despite central drive to breathe and inspiratory muscle activity
Predisposing factors Increased BMI Increased age Higher prevalence in men than women Higher prevalence in 3- to 5-year old children