CHRONOBIOLOGY AND ASSESSING SLEEP Flashcards
% OF DIURNAL PREFERENCE WHICH IS GENETICALLY DETERMINED?
50%
CHRONOTYPE
Chronotype is the natural inclination of your body to sleep at a certain time, or what most people understand as being an early bird versus a night owl. In addition to regulating sleep and wake times, chronotype1 has an influence on appetite, exercise, and core body temperature.
TOP 2 MOST COMMON SLEEP DISORDERS AND WHO DO THEY AFFECT
Insomnia (more common in women) Sleep apnoea (more common in men because of the fat distribution, fat accumulating in the upper half of the body) - progesterone might be protective against sleep apnoea, so women are at higher risk after menopause when progesterone starts decreasing
IS SLEEP WALKING IN CHILDREN MORE COMMON IN GIRLS OR BOYS?
6 TIMES MORE COMMON IN BOYS
HOW LONG DOES IT TAKE AFTER FALLING ASLEEP FOR THE FIRST REM PERIOD TO OCCUR?
60-90 MINS
WHICH ASPECTS OF SLEEP CAN BE ASSESSED?
DURATION
QUALITY
ARCHITECTURE
ASSOCIATED PHENOMENA (e.g. sleep apnoea, leg movements etc)
DESCRIBE THE STRATEGIES FOR ASSESSING SLEEP DURATION
ASKING A PATIENT TO KEEP A DIARY
- cheap
- moderately objective
- sleep often underestimated (esp WASO) WASO is short for “Wakefulness After Sleep Onset.”
- useful as a therapeutic tool as well
ACTIGRAPHY - recording of movement (usually wrist) - prolonged recording possible (up to 6 weeks) Movement = wakeful Little movement = sedated No movement = sleep (dead!)
POLYSOMNOGRAPHY
- Recording of physiological variables
- Electrophysiology; EEG, EOG, EMG (mandibular, tibial), ECG
- Body movement
- Respiratory (Chest wall movement, Airflow, Airway pressures, Oximetry, CPAP pressures)
- Cardiovascular (Heart rate, Heart rate variability, Blood pressure)
- Video
BEGINNING OF SLEEP STAGING?
Approximately, 20 years after rapid eye movement (REM)
sleep discovery, in 1968 a group of sleep researchers under the
chairmanship of Rechtschaffen and Kales (R&K) met to
develop the first standardized criteria for sleep staging
(Rechtschaffen and Kales, 1968) in healthy adult subjects,
and for 40 years this was the only accepted system of scoring in
sleep research
Method: 30 second epoch (decide for each 30 secs which of the 4 categories is dominant, to get a sense of the architecture of sleep --> for a lot of epochs hard to determine the dominant) Categories: Wake Movement NREM (Stages 1-4) REM
EPWORTH SLEEPINESS SCALE
QUESTIONNAIRE FOR ASSESSMENT OF WAKEFULNESS
Likelihood of falling asleep in 8 common situations (0-3), maximum score 24
Normal score: 2-10
EPWORTH SCALE SCORE FOR INSOMNIA
0-6
EPWORTH SCALE SCORE FOR NARCOLEPSY
13-23
EPWORTH SCALE SCORE FOR OSA
4-23
MULTIPLE SLEEP LATENCY?
The Multiple Sleep Latency Test (MSLT) checks for excessive daytime sleepiness by measuring how quickly you fall asleep in a quiet environment during the day. Also known as a daytime nap study, the MSLT is used to diagnose narcolepsy and idiopathic hypersomnia.
The MSLT is a full-day test that consists of five scheduled naps separated by two-hour breaks. This test is always done following a sleep study that measures your sleep quality and duration. During each nap trial, you will lie quietly in bed and try to go to sleep. Once the lights go off, the test will measure how long it takes for you to fall asleep. You will be awakened after sleeping 15 minutes. If you do not fall asleep within 20 minutes, the nap trial will end.
Each nap will be taken in a dark and quiet sleep environment that is intended for your comfort and to isolate any external factors that may affect your ability to fall asleep. A series of sensors will measure whether you are asleep. The sensors also determine your sleep stage.
Mean Latency >10mins, normal
WHAT COMMONLY OCCURS WHEN A PERSON WITH NARCOLEPSY FALLS ASLEEP?
people often go straight from wakefulness to REM sleep (getting hyponogogic hallucinations)
MULTIPLE WAKEFULNESS?
THE MAINTENANCE OF WAKEFULNESS TEST
After monitored sleep
4 nap opportunities of up to 20mins
Darkened room: “Stay awake, please”
Mean Latency >11mins, normal
The Maintenance of Wakefulness Test (MWT) is used to measure how alert you are during the day. It shows whether you can stay awake for a defined period of time. The test is based on the idea that, in some cases, your ability to stay awake may be more important than how fast you fall asleep. This is an indicator of how well you can function and remain alert in quiet times of inactivity.
The test is performed in a dark room that is quiet. The test isolates you from outside factors that can influence your ability to fall asleep. These factors include such things as the following:
Temperature (too hot or too cold) Light Noise Activity After starting treatment for a sleep disorder, the MWT is used to see how well you can stay awake and function in daily activities. It is also used to help judge whether a person is too sleepy to drive or perform other daily tasks. This is critical when your job involves public transportation or safety. The results of the test will be only one factor used to assess the potential risk of a work-related accident.
