Sleep and Sleep Disorders Flashcards
Time in life spent sleeping
1/3
Brain plasticity
brain remodels and purges old information during sleep
purpose of sleep
- restoration
- conservation of energy
- allow processing of input
- memory consolidation depends on sleep
number of Americans who suffer form sleep disorders
40 million
percent of men and women with obstructive sleep apnea who are not clinically diagnosed
93% of women
82% of men
excessive daytime sleepiness impairs:
- human performance that can lead to accidents at work, at home, or on the road
- 31% drivers fall asleep at some point
- academic performance, learning, and judgment
- increased weight, mood disorders, stress, CV complications
definition of sleep
- reversible behavioral state of perceptual disengagement from and unresponsiveness to the environment
- a very complex amalgam of physiologic and behavior processes
- a process, unlike coma, that is physiologic, recurrent, and reversible
biologic clock activity
- the body’s master “clock” is located in the suprachiasmatic nucleus (SCN) of the hypothalamus
- light-dark signals reach the SCN via a retinohypothalamic track
- SCN cells are circadian oscillators, exhibiting a stable, biphasic firing cycle
- 24.18 hours is clock period
- clock is mainly determined by light and dark cycles
alerting effects of the biological clock
- oppose the homeostatic sleep drive with its alerting effect
- allow for consolidated WAKE during the subjective day
- Initiate a mid-day dip in biologic clock alerting activities
Homeostatic sleep drive
- proportional to the amount of previous WAKE and sleep debt.
- sleep debt builds throughout the day
amount of sleep needed for adults and children
- adults = 7-8 hrs
- children = >9 hrs
body clock
- responsible for alternating drives for wakefulness and sleepiness
- as long as there are no rapid shifts in environmental time cues (shift work or multiple time zone travel), the body clock allows us to consolidate sleep to the night and wakefulness to the day
how to keep circadian clock on time
- awake approximately the same time each day
- obtain bright light during daytime hours
how to maximize homeostatic sleep drive
- limit napping
- only go to bed when you’re sleepy
how to reduce arousals
- limit or eliminate caffeine intake
- shut down your day at least one hour before bedtime
principles of sleep hygiene
keep circadian clock on time, maximize homeostatic sleep drive, reduce arousals
how to improve sleep hygiene
- take hot showers or baths at least 2 hours before bedtime
- place the alarm clock where it cannot be seen
- keep the bedroom dark, quiet, and cool, with no pets
- avoid stressful activities in the evening
- use the bed only for sleep and intimacy
Sleep ROS
- do you wake up feeling rested and refreshed?
- how long does it take you to fall asleep?
- do you snore, or has your bed partner complained about you snoring?
- do you have any leg discomfort at night?
Two issues profoundly affected by sleeping disorders
diabetes and cardiovascular problems
Excessive daytime sleepiness vs. fatigue
- sleepiness: able to sleep if given a chance
- fatigue: tired but does not fall asleep (body is tired but mind is very active)
prevalence of insomnia
~30% within the last year
Risk factors of insomnia
- female gender (RR = 1.41)
- medical, psychiatric, and substance abuse issues
- social factors (many covary)
- possible genetic factors
- age
Markers of hyperarousal
- reduced parasympathetic tone
- increased basal metabolism
- elevated circulating catecholamines
- increased electroencephalogram (EEG) beta activity (cortical activation)
- elevated body temperature
- high activity of HPA axis
characteristics contributing to or reinforced by poor sleep hygiene
- tension anxiety, arousal in association with efforts to sleep, or in the usual sleeping environment
- negative expectations regarding ability to sleep
- clockwatching
- ability to fall asleep when not trying to
- better sleep away from home
cognitive behavioral treatment of insomnia
- counseling in sleep hygiene
- cognitive therapy and stimulus control therapy
- sleep restriction therapy
sleep restriction therapy
- for insomnia
- set alarm same time each morning
- no daytime naps
- sleep diary for 7 days and calculate total sleep per night (total sleep time = TST)
- set up schedule restricting time spent in bed to equal TST
- as sleep improves, bedtime advanced by 15-20 mins to go to bed earlier
Restless leg syndrome
-distressing need/urge to move the legs, usually accompanied by an uncomfortable, deep-seated sensation in the legs that is: 1. brought on by rest, 2. relieved with moving or walking, 3. worse in the night or evening (circadian)
Primary RLS
primary (idiopathic)
- no precipitating factor
- younger age onset
- genetic association
- autosomal dominant
- chromosome 12/14
secondary RLS
- iron deficiency (~25%)
- Pregnancy (~25%)
- Renal failure (up to 60%)
- Drugs (antidepressants, SSRIs)
RLS and pregnancy
- extremely common in pregnancy
- ~11-50%
- severity increases in 3rd trimester
- etiology could be anemia, abdominal distention, inactivity
- no increase in fetal risk
- parity increases risk in mothers in dose dependent way
