Sleep Flashcards
sleep
rapidly reversible state of reduced responsiveness, motor activity, and metabolism
polysomnogram
primary tool for assessing sleep for clinical and research purposes using 30 second epochs of EEG, EMG, and EOG
sleep architecture
*sleep stages occur in cycles lasting 90-120 minutes each
*4 to 5 cycles occur during a typical night of sleep
*typically, increased percentage of NREM in the first half of the night and increased percentage of REM in the second half
wakefulness on polysomnogram
*EEG 8-13 Hz (alpha)
*variable muscle movements
*eye movements present
stage N1 sleep
*transitional or light sleep (drowziness)
*at least 50% of epoch has low amplitude mixed theta (4-7 Hz)
*slow rolling eye movements
*little muscle
*VERTEX WAVES late in N1
stage N2 sleep
*largest proportion of sleep time in normal adults (40-55% of night); when teeth grinding occurs
*theta frequency dominates
*SLEEP SPINDLES 11-16 Hz, central, brief
*K complexes (negative sharp followed by a positive, last > 0.5 sec
what stage of sleep is characterized by sleep spindles
stage N2 sleep
stage N3 sleep
*deep or slow wave sleep
*about 10-20% of sleep
*sleepwalking, night terrors, and enuresis occur during this stage
*at least 20% of epoch is 0.5-2 Hz high amplitude delta
*occurs more in first half of night
REM (stage R) sleep - polysomnograph
*EEG is low voltage, mixed with sawtooth 2-6 Hz brief bursts
*EOG with conjugate irregular, sharply peaked eye movements initial phase < 500 msec
*ATONIA on EMG (inhibition of alpha motor neurons)
which stage of sleep is characterized by atonia
REM sleep
REM sleep characteristics
*characterized by atonia and rapid eye movements
*less than 25% of sleep time, onset after 90 minutes, duration increases later in night
*typically associated with vivid dreams
*increased brain O2, erections, variable and increased pulse and BP, may serve memory processing functions
phasic and tonic REM
-phasic REM: bursts of rapid eye movements, respiratory variability, and brief EMG (twitches)
-tonic REM: fewer eye movements, more limited motor activity
arousals (during sleep)
*abrupt shift of EEG frequency that lasts at least 3 seconds with 10 seconds of stable sleep preceding the change
*waking up transiently then returning back to the stage of sleep they were in
*if during REM, requires a concurrent increase in EMG for at least 1 second
medications that suppress REM
*sedative-hypnotic
*barbiturates
*antiepileptic drugs
*beta blockers
*MAOI
*SSRIs
*stimulants
*tricyclic antidepressants
*EtOH
medications that enhance REM when you withdraw from them
*EtOH
*BDZ
*TCA
*MAOI