Lecture 5 Flashcards
Sleep cycles
Each cycle lasts approximately 90 minutes
Alternates between REM and NREM (SWS)
SWS predominates first half of the night (slow wave sleep)
REM predominates second half
Daylight savings
Even a small change in sleep can cause problems
In the days immediately following daylight savings time (spring forward) there has been:
* 24% increase in myocardial infarction
* 6% increase in traffic accidents
* Increased mood disturbances and suicide
* Volatility in the stock markets (Attributed to impact of sleep deprivation on frontal lobe functioning…)
American Academy of Sleep Medicine: these seasonal
time changes should be abolished in favor of a fixed, national, year-round standard time.
Effects of Sleep Deprivation
- Extensive sleep deprivation is fatal in rats
- Death! (see next slide)
- One potential etiology: Sleep destroys free radicals and prevents their damaging effects
Fatal Familial Insomnia
Inherited neurological disorder
progressive insomnia
Causes:
* Results in damage to portions of thalamus
* Death after 12 months
Adenosine (inhibitory)
Inhibitory response
Steps:
1) Astrocytes store glycogen for “emergency energy,” break down into glucose to give to neurons
2) By product of that is adenosine,
3) Accumulation of adenosine triggers DELTA sleep
4) throughout day body naturally accumulates adenosine, which helps us feel sleepy at night
5) during the night, body recycles adenosine
Sleep Deprivation = ↓ Glycogen Stores & ↑ Adenosine = SLEEPINESS
What does sleep deprivation due to your glycogen stores and adenosine levels
Sleep Deprivation = ↓ Glycogen Stores & ↑ Adenosine = SLEEPINESS
Caffeine and Adenosine
Caffeine blocks adenosine receptors = ↓ Sleepiness BUT ↑ fatigue.
it only reduces the feeling of sleepiness but your body is still sleepy
Where is melatonin produced and when
Produced by the Pineal Gland in response to evening/darkness about 2 hours before normal sleep time
_____ is converted into melatonin
Serotonin
Exogenous melatonin
Exogenous melatonin = take 1-2mg 30 to 1 hr before bedtime (higher just pee it out)
Doesn’t keep you asleep, just puts you to sleep
Who should you not prescribe melatonin to?
older adults with dementia & those with dementia
Sleep hormones
Acetylcholine: high when you are awake, low in SWS, and high in REM
Most go high to low
Sleep trends in US: _____ less sleep than earlier generations
25
Sleep trends in US: _____ americans in shift work
20
Sleep trends in US: _____ adults report falling asleep during the day without meaning to at least once a
month
40
Insomnia effects how many adults, and what gender
30% of adults
more common in women (40%) and men (30%)
Primary and secondary insomnia
Primary insomnia = difficulty falling asleep after going to bed or after awakening during the night.
Secondary insomnia = inability to sleep due to another mental or physical condition (e.g., pain, medication)
Insomnia disorder and medical conditions
Insomnia disorder has a high comorbidity rate with chronic medical conditions (20% to 80%)
Drug dependency insomnia—within 3 days of drinking (causes bad sleep)
Rebound insomnia
Chronic use of sleep-promoting drugs can cause rebound insomnia
Most effective treatment for Insomnia
CBTI most effective tx
drugs and CBTI=no advantage
Narcolepsy: causes
Orexin-Related Neurological d/o
* missing >85% Orexin-Producing Neurons
* REM-related symptoms occur inappropriately
* Hereditary component
Orexin: high during alert/awake
Narcolepsy: cataplexy
sudden muscle weakness/paralysis
- Triggered by strong emotional reaction or physical exertion
- Remain fully conscious.
- Loss of muscle control d/t massive inhibition of motor neurons in spinal cord
Narcolepsy: Sleep paralysis
inability to move before onset of sleep or waking
hypnagogic Hallucinations (visual)
Narcolepsy: Sleep attacks
overwhelming urge to sleep
* Triggered under boring & monotonous conditions
* Lasts 2-5 mins
* Wake up refreshed.
Most people have sleep attacks (overwhelming urge to sleep during something boring) -> but people with narcolepsy just fall asleep
Narcolepsy treatment
Modafinil, SSRIs
REM Sleep Behavior D/O
Lack of muscle paralysis during REM –> acting out of dreams
Can be comorbid narcolepsy (Drugs that are used to treat the symptoms of cataplexy will worsen the
symptoms of REM sleep behavior disorder)
later in life (if you are young, caused because of medication or leisures)
Neurodegenerative (common to develop parkinsons or Dementia with lewy body)
REM Sleep Behavior D/O: Treatment
Treatment = Clonazepam
Sleep Apnea
Difficulties sleeping and breathing at the same time ↑CO2 = stimulates chemoreceptors –> wake up gasping for air & decreased slow wave activity
Untreated Sleep Apnea
Significant deficits in attention, memory, & exec fxns.
Increase risk of Stroke, MI
In kids 2.5x risk of behavioral problems
Sleep Apnea: Treatment
CPAP, BiPAP
* Can reverse cognitive deficits with treatment
Types of sleep apnea
Obstructive Sleep Apnea = d/t narrowing of airway (obesity, enlarged tonsils, hormonal changes)
Central Sleep Apnea = brain does not signal need to breath.
