Vosko Sleep Flashcards
a number of common situations when sleep patterns change
During illness (“sick behavior”)
Affective changes (depression, stress, etc.)
Throughout the aging process
Seasonal changes (esp. during time changes)
Taking medication
Diet
Hormonally-induced changes
ie. aggressive treatment not always needed
Insomnia
initiation or maintaining?
Mech: psycho, neuro, genetic, pharm
How to dx? Polysom
Parasomnias
dissociated sleep states
mech: neuro, pharm, unknown
how to dx: Polysom
Hypersomnias
eg: narcolepsy
Mech: neuro (orexin)
how to dx: polysom
sleep-disordered breathing
eg: OSA, CSA, hypovent.
mech: structural, neuro, pharm
how to dx? polysom
circadian rhythm disorders
eg: jet lag, ASPS, DSPS
Mech: physio, pharm, genetics
how to dx: actigraphy
Neuro-degenerative disorders
e. g.: parkinson’s, ALS, Alzheimer’s
mech: neuro, pharm
How to dx: imaging, motor tests, cognitive tests, etc.
Determine if feeling tired (fatigue) is the same as feeling sleepy
Do I have a problem with sleep itself, or am I just feeling tired?
Range of “normal” (without chronic sleep disorder) totals: 0-10
What steps do I take next? Determine the nature: Insomnia Parasomnia Hypersomnia Sleep-disordered breathing Circadian rhythm disorder Neurodegenerative disorder
Micro-arousals:
Brief awakenings from sleep (usually < 15 seconds). Do not have conscious recollection.
Micro-sleeps:
Brief (seconds in duration) sleep episodes during wakefulness. May not have conscious recollection.
Perceived Insomnia:
Believing one has insomnia while showing the behavioral and polysomnographic characteristics of someone with normal sleep.
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 (Paradoxical Sleep)
Increased arousal thresholds Decreased thermoregulation Decreased postural muscle tone== most compromised Rapid Eye Movements Vivid recall of dreams Asynchronous EEG 25% of Total Sleep Time Prominent in later phases of sleep
Reflex circuits and muscle tone
Muscle tone is the resting level of tension in a muscle
Allows muscle to make an optimal response to voluntary or reflexive movement by keeping them in a state of readiness to resist stretch
During a night’s sleep, we cycle through NREM-REM in 90 minute cycles
Longer periods of REM in second half of night
- Deprivation of NREM sleep leads to “rebound” of NREM sleep
- Deprivation of REM sleep leads to a “rebound” of REM sleep
- SOREMPs (Sleep Onset REM Periods) are also indicative of other sleep disorders (eg. Narcolepsy)
Polysomnography is used to measure physiological changes during sleep
Pay attention to the amplitude of EEG waves
Pay attention to the frequency of EEG waves
Pay attention to tone in EMG
Pay attention to activity in EOG
Stage 2 sleep clearly defined by:
K complexes
Sleep spindles
Stage 3 and 4 sleep defined by:
Delta waves
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
For a prolonged, consolidated sleep, timing is everything
Circadian rhythm phase misalignment can shorten sleep cycles or misplace them relative to the day and cause excessive daytime sleepiness
Align core body temperature minimum with middle of the sleep period for longest sleep
Actigraphy
is used to determine if there is circadian misalignment of the sleep-wake schedule
during wakefulness, brainstem nuclei promote…
excitatory tonic input to motor neurons. Provides “muscle tone.”
Respiratory muscles and sleep
Both a tonic input and a phasic (respiratory drive) input regulate respiratory muscles
When tonic input is diminished (as in sleep), respiration relies more on phasic inputs
In REM sleep, there is heavy reliance on phrenic motor neurons for all sleep-related breathing
Diminished tonic input during sleep occurs via
GABA-ergic and/or Glycinergic activity in the spinal cord and cranial nerve nuclei
