Case 1 quality and quantity
1. Stages of sleep
- Sleep architecture refers to the electrophysiological structure of sleep. The objective
measurement of the internal structure of sleep is based on a polysomnography (PSG)
recording, which consists of measuring electrical activity of the brain; muscle tones
around the eyes, chin, and legs; and breathing patterns. Sleep consists of two main
categories: REM and NREM. NREM sleep is further divided into three stages: Stage 1
(N1), Stage 2 (N2), and Stage 3 (N3).
- Stage N1 is the lightest of the three NREM stages of sleep. It is easy to be awakened
from sleep during Stage N1; and when awakened, an individual is least likely of all
NREM sleep stages to perceive having been asleep. N3=deep sleep, N2 =
intermediate.
- The brain waveform during Stage N2 is characterized by sharp spikes (known as K-
complexes) as well as short bursts of activity (known as sleep spindles).
- REM sleep is characterized by dreaming, REM, loss of muscle tone (muscle atonia,
believed to function as dream enactment prevention), irregular breathing, and poor
thermoregulation.
- Sleep begins with the lightest of the NREM stages (N1) and proceeds through the
NREM sleep stages, including the deepest stage (N3), until the first REM episode
occurs, within an average of 70 min. The period from the onset of sleep until the first
REM episode is the first sleep cycle. The rest of the night is spent cycling between
NREM and REM sleep in a similar fashion. With the exception of the first cycle,
which lasts 70 min, the duration of subsequent cycles is roughly 90 min. Brief
awakenings during sleep stage transitions are normal.
- Polysomnography: The data collected informs about aspects of sleep quality: minutes
to fall asleep, number of awakenings, duration of each awakening, total sleep time,
and sleep efficiency
- Actigraphy: Another objective method for assessing sleep is based on movement of
the wrist. A wrist-worn device (actigraph), which has a very sensitive motion sensor,
collects movement data. Validated algorithms are then used to score each minute as
sleep or wakefulness. actigraphs cannot provide information about sleep stages. One
of the benefits of actigraphy is its relatively unobtrusive nature and low cost, relative
to PSG.
- Sleep diaries: which provide daily sleep data, and sleep questionnaires, which
retrospectively assess sleep behaviors and symptom severity. Assessing daytime
sleepiness is also part of a comprehensive sleep assessment because sleepiness can
constitute a safety risk and because severe sleepiness is a diagnostic symptom of some
sleep disorders.
- Multiple Sleep Latency Test (MSLT): The MSLT measures sleepiness as defined by
the propensity to fall asleep. The test consists of four or more PSG-monitored daytime
nap opportunities, usually 2 hr apart. Each nap opportunity lasts 20 min. The MSLT
score is the average number of minutes to fall asleep over all nap opportunities, in
which naps that were not associated with sleep are scored as 20. A higher MSLT score
reflects lower level of sleepiness. Scores less than 5 min are interpreted as an
indication of excessive sleepiness.
- Maintenance of Wakefulness Test (MWT): The MWT test consists of multiple
PSGmonitored, 40-min trials, in which the individual is seated in a dark and quiet
room and is instructed to stay awake. The MWT score is the average time to fall
asleep across the nap opportunities, in which naps that were not associated with sleep
are scored as 40. A higher MWT score reflects higher level of alertness
1
, 2. How much sleep do you need?
Article Hirshkowitz
- Methods: An 18-member multidisciplinary expert Panel, comprised of sleep
researchers, physicians, and experts in other areas of medicine, physiology, and
science, was assembled by the NSF. A rigorous consensus process, which included
evaluation of a systematic literature review and participation in 2 rounds of consensus
voting, was undertaken by the Panel
- Newborns (0-3 months): 14- to 17-hour sleep, for newborns, experts only voted on
appropriate sleep duration for overall health, with the understanding that this includes
components of cognitive, physical, and emotional health. Sleep duration
recommendations for newborns may not apply during the first few days of life because
long sleep can be normal.
- Infants (4-11 months): 12-15 hours sleep
- Toddlers (1-2 y/o): 11-14 h sleep, association between short sleep duration, obesity,
hyperactivity impulsivity, and lower cognitive functioning. Long sleep duration could
interfere with toddlers’ exploration of their physical and social environment and
thereby impede motor, cognitive, and social development
- Preschool (3-5 y/o): 10-13 h sleep , physical and emotional health effects if too short
sleep
- School age (6-13 y/o): 9-11 h sleep, associations between short sleep in school-aged
children and lower cognitive functioning and poorer academic performance.
- Teenager (14-17 y/o): 8-10 h sleep, There was concern about short sleep duration in
teenagers potentially leading to decreased alertness, automobile accidents, depressed
mood, obesity, poor health, and low academic performance. Interventional research
shows that delaying school-start times approximately 1 hour later increases students’
sleep duration and decreases daytime sleepiness
- Young adult (18-25 y/o): 7-9 h sleep, short sleep duration is associated with increased
fatigue, decreased psychomotor performance, accidents, poor physical and
psychological health, and low academic performance. In addition, healthy sleep
patterns enhance adjustment and performance in college years; early bedtimes, wake
times, and napping correlate with the high academic performance. Finally, extended
sleep leads to substantial improvements in daytime alertness, reaction time, and mood.
- Adult (26-64 y/o): 7-9 h sleep, Sleep deprivation’s adverse effect on multitasking
performance, weight regulation, job safety, mental health, sugar regulation, blood
pressure, and cardiovascular health was noted, particularly with nighttime sleep
deprivation during the workweek
- Older adult (65+): 7-8 h sleep, older adults sleeping 6-9 hours have better cognitive
functioning, lower rates of mental and physical illnesses, and enhanced quality of life
compared with shorter or longer sleep durations. However, considerable evidence
shows that long sleep duration (≥9-10 hours) in older adults is associated with
morbidity (eg, hypertension, diabetes, atrial fibrillation, poor general health) and
mortality. Excessive sleep may be a marker in older adults signaling the need for
medical, neurological, or psychiatric evaluation. Daytime napping is perceived as
common, but not universal, in older adults. However, older adults report more daytime
sleepiness than younger adults.
3. Differences between ages?
Article Manber
Macro sleep changes
2
1. Stages of sleep
- Sleep architecture refers to the electrophysiological structure of sleep. The objective
measurement of the internal structure of sleep is based on a polysomnography (PSG)
recording, which consists of measuring electrical activity of the brain; muscle tones
around the eyes, chin, and legs; and breathing patterns. Sleep consists of two main
categories: REM and NREM. NREM sleep is further divided into three stages: Stage 1
(N1), Stage 2 (N2), and Stage 3 (N3).
- Stage N1 is the lightest of the three NREM stages of sleep. It is easy to be awakened
from sleep during Stage N1; and when awakened, an individual is least likely of all
NREM sleep stages to perceive having been asleep. N3=deep sleep, N2 =
intermediate.
- The brain waveform during Stage N2 is characterized by sharp spikes (known as K-
complexes) as well as short bursts of activity (known as sleep spindles).
- REM sleep is characterized by dreaming, REM, loss of muscle tone (muscle atonia,
believed to function as dream enactment prevention), irregular breathing, and poor
thermoregulation.
- Sleep begins with the lightest of the NREM stages (N1) and proceeds through the
NREM sleep stages, including the deepest stage (N3), until the first REM episode
occurs, within an average of 70 min. The period from the onset of sleep until the first
REM episode is the first sleep cycle. The rest of the night is spent cycling between
NREM and REM sleep in a similar fashion. With the exception of the first cycle,
which lasts 70 min, the duration of subsequent cycles is roughly 90 min. Brief
awakenings during sleep stage transitions are normal.
- Polysomnography: The data collected informs about aspects of sleep quality: minutes
to fall asleep, number of awakenings, duration of each awakening, total sleep time,
and sleep efficiency
- Actigraphy: Another objective method for assessing sleep is based on movement of
the wrist. A wrist-worn device (actigraph), which has a very sensitive motion sensor,
collects movement data. Validated algorithms are then used to score each minute as
sleep or wakefulness. actigraphs cannot provide information about sleep stages. One
of the benefits of actigraphy is its relatively unobtrusive nature and low cost, relative
to PSG.
- Sleep diaries: which provide daily sleep data, and sleep questionnaires, which
retrospectively assess sleep behaviors and symptom severity. Assessing daytime
sleepiness is also part of a comprehensive sleep assessment because sleepiness can
constitute a safety risk and because severe sleepiness is a diagnostic symptom of some
sleep disorders.
- Multiple Sleep Latency Test (MSLT): The MSLT measures sleepiness as defined by
the propensity to fall asleep. The test consists of four or more PSG-monitored daytime
nap opportunities, usually 2 hr apart. Each nap opportunity lasts 20 min. The MSLT
score is the average number of minutes to fall asleep over all nap opportunities, in
which naps that were not associated with sleep are scored as 20. A higher MSLT score
reflects lower level of sleepiness. Scores less than 5 min are interpreted as an
indication of excessive sleepiness.
- Maintenance of Wakefulness Test (MWT): The MWT test consists of multiple
PSGmonitored, 40-min trials, in which the individual is seated in a dark and quiet
room and is instructed to stay awake. The MWT score is the average time to fall
asleep across the nap opportunities, in which naps that were not associated with sleep
are scored as 40. A higher MWT score reflects higher level of alertness
1
, 2. How much sleep do you need?
Article Hirshkowitz
- Methods: An 18-member multidisciplinary expert Panel, comprised of sleep
researchers, physicians, and experts in other areas of medicine, physiology, and
science, was assembled by the NSF. A rigorous consensus process, which included
evaluation of a systematic literature review and participation in 2 rounds of consensus
voting, was undertaken by the Panel
- Newborns (0-3 months): 14- to 17-hour sleep, for newborns, experts only voted on
appropriate sleep duration for overall health, with the understanding that this includes
components of cognitive, physical, and emotional health. Sleep duration
recommendations for newborns may not apply during the first few days of life because
long sleep can be normal.
- Infants (4-11 months): 12-15 hours sleep
- Toddlers (1-2 y/o): 11-14 h sleep, association between short sleep duration, obesity,
hyperactivity impulsivity, and lower cognitive functioning. Long sleep duration could
interfere with toddlers’ exploration of their physical and social environment and
thereby impede motor, cognitive, and social development
- Preschool (3-5 y/o): 10-13 h sleep , physical and emotional health effects if too short
sleep
- School age (6-13 y/o): 9-11 h sleep, associations between short sleep in school-aged
children and lower cognitive functioning and poorer academic performance.
- Teenager (14-17 y/o): 8-10 h sleep, There was concern about short sleep duration in
teenagers potentially leading to decreased alertness, automobile accidents, depressed
mood, obesity, poor health, and low academic performance. Interventional research
shows that delaying school-start times approximately 1 hour later increases students’
sleep duration and decreases daytime sleepiness
- Young adult (18-25 y/o): 7-9 h sleep, short sleep duration is associated with increased
fatigue, decreased psychomotor performance, accidents, poor physical and
psychological health, and low academic performance. In addition, healthy sleep
patterns enhance adjustment and performance in college years; early bedtimes, wake
times, and napping correlate with the high academic performance. Finally, extended
sleep leads to substantial improvements in daytime alertness, reaction time, and mood.
- Adult (26-64 y/o): 7-9 h sleep, Sleep deprivation’s adverse effect on multitasking
performance, weight regulation, job safety, mental health, sugar regulation, blood
pressure, and cardiovascular health was noted, particularly with nighttime sleep
deprivation during the workweek
- Older adult (65+): 7-8 h sleep, older adults sleeping 6-9 hours have better cognitive
functioning, lower rates of mental and physical illnesses, and enhanced quality of life
compared with shorter or longer sleep durations. However, considerable evidence
shows that long sleep duration (≥9-10 hours) in older adults is associated with
morbidity (eg, hypertension, diabetes, atrial fibrillation, poor general health) and
mortality. Excessive sleep may be a marker in older adults signaling the need for
medical, neurological, or psychiatric evaluation. Daytime napping is perceived as
common, but not universal, in older adults. However, older adults report more daytime
sleepiness than younger adults.
3. Differences between ages?
Article Manber
Macro sleep changes
2
