Lec 46 Sleep Disorders Flashcards
What is the function of sleep?
- physical restoration
- optimize waking neurocognitive and emotional function
- learning, emotional processing
- health + survival
What kind of waves in awake state with eyes open? eyes closed?
eyes open = beta (highest freq)
eyes closed = alpha = 8-14 Hz
What are the stages of non-rem sleep? what percent of sleep do they make up?
stage 1 = 5% of sleep = light sleep
stage 2 = 45% of sleep - deeper sleep
stage 3/4 = 25% of sleep- deep slow wave sleep
What kind of sleep is stage 1? type of waves?
light sleep ~5% of sleep
have theta waves [4-7 Hz]
muscle activity slows; occasional twitches
What is mneumonic for EEG waves of awake/sleep?
At night, BATS Drink Blood
- Beta [awak open eyes]
- Alpha [awake closed eyes]
- Theta [1]
- Sleep spindles + K complex [2]
- Delta [3/4]
- Beta [REM]
What kind of sleep is stage 2? type of waves?
deeper sleep = ~45% of sleep
theta continues plus have sleep spindles and K complexes
breathing and HR slow
What kind of sleep is stage 3/4? type of waves?
deep/slow sleep = ~25% of sleep
delta waves (0.5-2 Hz) = slow wave
limited muscle activity
when sleepwalking, night terrors, bedwetting occur
What stage of sleep has sleep spindles and k complexes?
stage 2
What are characteristics of REM sleep?
- makes up ~25% of sleep; 4-6 episodes per night
- absent motor tone/activity
- rapid eye movements
- dreaming
- increased HR/BP, brain uses more O2
may serve memory processing function
What is the pattern of sleep cycle?
one cycle: 1 –> 2 –> 3 –> 4 –> 3 –> 2 –> REM
repeats ~ 90-120 min
more REM in second half of night
What is sleep latency?
the time from lights out to first NREM stage 1
- usually takes 10-20 min
What is REM latency?
the time from sleep onset to first REM
- usually takes 90-100 min
What is sleep efficiency?
amount of sleep/total time in bed * 100
How much sleep does average adult need?
7-9 hrs
How much of day do infants sleep? how much REM?
sleep 2/3 of day
50% of sleep in REM
What happens to sleep cycle with aging?
increased: sleep latency, noctural awakenings, NREM stage 1
decreased: delta, REM, REM latency, sleep efficiency
What does polysomnography measure?
- EEG to get brain electrical acivity
- electro-oculography to measure eye movements
- EMG to measure muscle tone
What is multople sleep latency test?
- to assess objective daytime sleepiness
- monitor sleep for a night then allow pt to nap 4-5 times at 2 hr intervals during day and see how many times they go into REM
if go straight into REM during nap –> sign of narcolepsy
What is a dyssomnia?
disorder of too little or too much sleep
What is a parasomnia?
abnormal behavior or psych even during specific sleep stages or during transition wake to sleep
What is definition of sleep apnea?
repetitive episodes of complete or partial cessation of air flow during sleep that causes ox desaturation and ends with brief arousals
- may be due to reduced resp drive [central] or upper airway obstruction [obstructive]
What are symptoms of sleep apnea?
- excessive daytime sleepiness
- snoring, choking, gasping during sleep
also: - impaired conc, memory loss
- associated with obesity/HTN
What causes each of the 2 types of sleep apnea?
central: due to decreased resp drive from brainstem lesion
obstructive: due to upper airway obstruction, associated with obesity
What are consequences of obstructive sleep apnea?
- increased mortality
- CHF, stroke, HTN
How prevalent is obstructive sleep apnea?
~15%
What are treatments for obstructive sleep apnea?
- weight loss
- positional therapy
- postive airway pressure therapy
What is narcolepsy?
profound excessive daytime sleepiness
tetrad of signs: daytime somnolence, cataplexy, sleep paralysis, hallucination
- have repeated attacks of irresistible sleep with REM immediate onset
- cataplexy = REM sleep during wakefulness causes muscle weakness
- sleep paralysis: paralysis during waking + falling asleep
- hallucinations
- often have normal polysomnogram
When does narcolepsy normally present?
- teens - early 10s; symptoms worsen for first few years then persist
What is pathophysiology of primary narcolepsy? secondary?
- genetic or autoimmune origin
- destruction of hypothalamic orexin secreting neurons in lateral hypothalamus
secondary: head trauma, MS, craniopharyngioma, tumor in upper brainstem, hypthalamic sarcoid granuloma
How do you treat narcolepsy?
daytime – stimulants (amphetamines, modafinil)
nighttime – sodium oxybate
What is ondine’s curse? cause?
primary hypoventilation syndrome
- total loss of automatic breathing esp. in sleep
- have apneic periods that lead to awakenings
due to: absent external arcuate nuclei of medulla and depleted neurons in medullary respiratory areas
What is kleine levin syndrome?
- repeated episodes of excessive daytime somnolence
- hypersexuality
- hyperphagia [eat a lot]
- episodes last days to wks
etiology unknown
What is a circadian rhythm disorder?
misalignment between desired sleep-wake scheudle and endogenous circadian-rhythm
What are symptoms of shift work sleep disorder?
- excessive sleepiness during work hours scheduled during usual sleep period
- insomnia when attempting to sleep during usual wake period
- mood instability
- associated with insomnia, excessive sleepiness, or both
- non-specific GI symptoms
- work related errors, industrial accidents
What is restless leg syndrome?
spontaneous leg movement/urge to move leg
occurs at rest only
has negative impact on sleep initiation and maintenance
What is etiology of restless leg?
genetic = dominant inheritance
secondary: iron deficiency, renal disease, diabetes, MS, parkinsons
When does sleepwalking disorder occur?
non-rem sleep stage 3-4
when does sleep terror occur?
non-rem stage 3-4
what does nightmare disorder occur?
REM sleep
for non-rem sleep disorder: What is timing? amnesia? confusion? dreaming? demographics? autonomic activity?
- occurs in first 2 hours of night
- amnesia occurs
- confusion follows
- occurs in children
- variable autonomic activity
for rem sleep disorder: What is timing? amnesia? confusion? dreaming? demographics? autonomic activity?
- occurs anytime
- no amnesia = vivid dream recall
- no confusion
- occurs in older men
- high autonomic activity
acting out dreams, unresponsive to environment
What is cause of non-rem sleep disorders?
disorders of arousal –> sudden brief but incomplete arousal
genetic component to it
its relatively benign
What causes REM sleep disorders?
idiopathic
can be early manifestation of neurodegeneration [PD]
