Sleep Disorders Flashcards
stage 1
drowsiness and early eeg slowing
stage 2
asleep but easily aroused
Stage 3 and 4
sleep deepens, harder to arouse, slower delta wave eeg recorded
when does first REM period occur
about 90 mins after sleep begins, reoccurs every 90 mins thereafter lengthening in time from a few mins to an hour
when is limb hypotonia maximal?
in REM sleep
eeg recording during REM sleep
similar to that of wake state, recallable dreams occur, important for reinforcing memory traces
ARAS (ascending reticular activating system)
- important for arousal and wakefulness
- arises from rostral pons, caudal midbrain, posterior hypothalamus, and basal forebrain to activate cerebral cortex directly or via thalamus
what does ARAS suppress
ventrolateral preoptic area of the hypothalamus
what does an ARAS lesion (aka ischemic infarct of upper brain stem) cause
persistent somnolence or coma
pontine REM center
activates the brain stem gaze centers responsible for typical REM eye movements and induces hypotonia and inc autonomic activity by descending reticulospinal pathways
What area promotes REM and NREM sleep
preoptic area of the ventrolateral hypothalamus which receives input from suprachiasmatic nucleus and has receptors for sleep-inducing peptides and cytokines
sleep apnea
- daytime sleepiness
- frequent episodes–>nocturnal hypoxemia–>pulm HTN or cardiac arrhythmias
obstructive sleep apnea
- 2/2 upper AW obstruction despite contraction of diaphragm and chest wall muscles
- typically obese
how is OSA diagnosis made
- overnight sleep study
- EEG, EKG
- oximetry
- respiratory and videotape monitoring
OSA tx
- weight loss
- uvulopalatopharyngoplasty
- mask devices delivering pressurized oxygen d/r sleep
central sleep apnea
- occurs in absence of any diaphragmatic or respiratory effort to breathe
- may need mech ventilation while they sleep
define narcolepsy
- REM sleep at inappropriate times
- hypocretin (orexin) deficiency
classic features of narcolepsy
- narcoleptic attacks
- cataplexy
- sleep paralysis
- visual hallucinations when falling asleep/waking up
narcoleptic attacks
-abrupt, multiple, intrusions of sleep during daytime activities
define cataplexy
- periodic loss of muscle tone provoked by emotional triggers
- slump to ground b/c of REM limb hypotonia; stays awake, recalls event
sleep paralysis
-occurs when REM hypotonia transiently prevents pt from getting out of bed on awakening
REM and narcolepsy
-recallable dreams of REM=basis for vivid hallucinations experienced by narcolepsy pts when falling asleep (hypnagogic hallucinations) or waking up (hypnopompic hallucinations)
how is narcolepsy diagnosis made
-multiple sleep latency tests where abnormally early onset of REM is recorded
medications to enhance wakefullness in narcoleptic pts
- Methylphenidate (amphetamine-like stimulants)
- Modafinil (stimulants unrelated to amphetamine)
- —Mo can also treat daytime somnolence from sleep apnea
what is helpful in reducing cataplexy
-drugs with REM suppressing properties like TCAs
insomnia
-hypnotics are helpful for short-term insomnia
somnambulism (sleep walking)
- disorder of stage 4 sleep
- sometimes assoc with bed wetting in kids
stage 4 disorders
- sleep walking
- night terrors
REM behavior disorder
- older male pts lack nml hypotonia of REM
- often preceds onset of Parkinson’s dz or Lewy body dementia
