Sleep Flashcards
What does an EEG record?
Wave of electrical activity from the pyramidal cells in the cerebral cortex
Why are signals from an EEG averaged?
To reduce the noise of the brain and isolate the repeated signal
When are EEGs useful?
Evaluating MS
What are alpha waves associated with?
state of relaxed wakefulness in an adult with their eyes closed
Where in the brain are alpha waves more prominent?
occipital and parietal areas
When do alpha waves change to beta waves?
rhythm if eyes open or in response to other sensory stimuli. Mental concentration such as that required to do arithmetic problems will also cause a change to the beta rhythm.
Beta waves have a larger or smaller amplitude than alpha waves?
Smaller
desynchronized EEG = ?
Beta waves
Where are beta waves seen most prominently?
Frontal region
What are delta and theta waves associated with?
stages of sleep in an adult
What is the order of the speed of waves (alpha, beta, theta, delta)? What are the ranges of each?
Beta (13-30 hz)
Alpha (8-13 hz)
Theta (4-7)
Delta (0.5 - 3.5)
Why do we sleep?
increase interstitial space in the brain and contribute to the removal of potentially neurotoxic waste products
that sleep has a key role in promoting learning-dependent synapse formation
What type of waves are seen when you are awake with eyes open?
beta
What type of waves are seen when you are awake but relaxed with eyes shut?
alpha
What happens with sleep deprivation?
Increased eating
Lower weight
What happens during the awake to sleep transition?
Move from beta waves to alpha waves
How many stages of sleep are there?
4 + REM
What is stage 1 of sleep? What waves are seen here?
Transition from awake to asleep–theta waves prominent
What is stage 2 of sleep? What waves are seen here?
Light sleep K complexes and sleep spindles
What is stage 3 of sleep? What waves are seen here?
moderately deep sleep some delta waves (more than 20% less than 50%)
What is stage 4 of sleep? What waves are seen here?
deep sleep - delta waves more than 50% of period
Is there a definite transition from awake to sleep?
No
Sawtooth waves are indicative of what stage of sleep?
REM
Does the brain use more or less oxygen when in REM sleep?
Less
What happens to body temp and metabolic rate in REM?
Lowers
What happens to BP and HR in REM?
Lower
What happens to respiratory rate in REM?
Lower
What happens to the muscles in REM sleep?
Muscles relaxed but major postural adjustments made about every 20 minutes.
Threshold for arousal increases as EEG wave frequency does what?
Decreases (So it is harder to arouse sleeper in Stage 4 sleep than Stage 1.)
What hormone is released during sleep?
GH–more than 70% of GH released during the first half (mainly slow wave sleep) of a person’s nightly sleep.
Why is REM sleep called paradoxical sleep?
since EEG similar to awake EEG.
What are PGO spikes? What are these spikes associated with?
(pontine - geniculate - occipital) associated with bursts of eye movements
What happens to the heart and respiration in REM sleep (besides slowing)?
Irregularity
What are the two muscles that do not have decreased muscle tone in REM sleep?
Eyes
Respiratory muscles
How long does REM takes to get to?
90ish minutes
What are REM dreams like compared to non-REM dreams?
longer, more visual/emotional
RED rebound is suppressed by what type of drugs?
EtOH
Barbiturates
What happens during sleep for teenage females that cause them to enter puberty?
GH bursts
When does stage four of sleep primarily appear?
first half
What neurons control REM sleep (2)? What do these neurons do?
Pontine neurons–excite spinal glycinergic neurons in the medulla which inhibit alpha neurons
What is the neurotransmitter release in the pons that excite medullary neurons, which in turn inhibit alpha motor neurons during sleep? What is the neurotransmitter for the medullary neurons?
Glutamate
Glycine
True or false: the human wake cycle is close to 24 hours, and there is little to no variation in the amount of sleep required per individuals
False–the 24 hours cycle thing it true, but the amount of sleep can vary between individuals
What is the photopigment in retinal cells that project to the suprachiasmatic nucleus?
Melanopsin
What controls melatonin synthesis in the pineal gland?
Suprachiasmatic nucleus
True or false: you should not have a REM episode in the first 60 minutes of sleep
True
What is the amount of sleep a newborn usually gets? Age 3-5?
16-18 in newborns
10-12 in toddlers
What percent of newborn sleep is REM sleep?
50%
How much REM sleep do newborns get?
8 hours (of the total 16-18 hours they get)
What is the correlation between cortisol and sleep?
Peaks in the AM after sleep, declines
What are the cells in the eyes that are responsible for the sleep-wake cycle?
Retinal ganglion cells
What is the pathway of control for the pineal gland from the suprachiasmatic nucleus?
Suprachiasmatic nucleus
IMLs
Superior cervical ganglion
Pineal gland
What happens to melatonin synthesis as light decreases?
Increases
What is the function of the cholinergic neurons in the pontomedullary junction?
These neurons fire at high rates during waking and REM sleep but are quiet during non-REM sleep.
What is the neurotransmitter utilized in the locus coeruleus in the sleep-wake cycle?
Norepi
What is the neurotransmitter utilized in the pontine raphe nucleus in the sleep-wake cycle?
Serotonin
What are the three nuclei that keep us awake?
Cholinergic nuclei
Locus Coeruleus
Raphe nuclei
What are the neurons that stimulate the brain stem nuclei to keep us awake? What other structure in the brain do these neurons stimulate?
Orexin neurons–also stimulate the tuberomammillary nucleus
What is the nucleus in the brain that inhibits the brainstem nuclei that keep us awake? What other structure does this inhibit?
VPLO–tuberomammillary nucleus
What is the MOA by which antihistamines cause drowsiness?
Block the stimulatory action of the Orexin neurons
What is the only neurotransmitter that is active in sleep? What part of sleep? Where does this neurotransmitter come from?
Acetylcholine in REM sleep
comes from the cholinergic nuclei of the pons
What is insomnia?
Disorders of initiating and maintaining sleep during normal sleeping periods.
What are parasomnias?
Disorders of the sleep cycle and other non-sleep dysfunctions associated with sleep
What nocturnal enuresis?
Bed wetting
What is somnambulism?
Sleep walking
What is the difference between sleep terrors and nightmares?
sleep terrors: occur during non-REM sleep, different from nightmares which are bad dreams in REM sleep
How long are sleep apnea pauses?
at least 10 seconds
What is REM sleep behavior disorder?
REM sleep without atonia or hypotonia
What are the three types of sleep apnea?
a. central sleep apnea
b. obstructive sleep apnea
c. mixed apnea
What is narcolepsy?
sleep attack associated with several REM like symptoms
What is cataplexy?
Abrupt attack of muscle weakness and hypotonia often triggered by an emotional stimulus
What is sleep paralysis?
Waking up paralyzed–symptom of narcolepsy
What are Hypnagogic hallucinations? What disease is this seen in?
hallucinations at transitions between wakefulness and sleep
Narcolepsy
Sleep onset REM is a symptom of what disease?
Narcolepsy
What is the decreased voluntary sleep latency seen in narcolepsy?
fall asleep faster
What is the cause of narcolepsy?
reduction or absence of hypothalamic cells that produce and secrete orexin (hypocretin)
d/t autoimmune disease
What is epilepsy?
repeated seizures
What are the two types of seizures?
a. generalized seizure vs. partial (localized or focal) seizure
b. primarily generalized vs. secondary generalized
What is primarily a generalized seizure?
One that starts everywhere at once?
What is a secondary generalized seizure?
One that started locally and spread
What is generalized epilepsy?
Bilaterally symmetrical and without localized onset
What are tonic-clonic (grand-mal) seizures?
LOC + tonic period of increased muscle tone followed by clonic period consisting of jerky movements
What are postictal states?
period of confusion following the seizure that usually last ~ 5 to 30 minutes
What is status epilepticus?
Continued seizure without pause between–this is a medical emergency
What are absence (petit mal) seizures?
Transient LOC for >5 seconds w/o loss of muscle tone
What is the EEG pattern for absence seizures?
3 per second spike and dome (or spike and wave) pattern seen on EEG during seizure
Is there a postictal state with absence seizures?
No
What are simple partial seizures?
Seizures localized to one area of the brain that do not affect general consciousness
What are complex partial seizures?
Focal seizures that result in LOC
What are jacksonian motor seizures?
Seizures in the motor cortex
Where are complex seizures usually seen?
temporal or frontal lobes
What are the symptoms of complex partial seizures?
LOC
Verbal and/or motor automatisms can occur
