Clinical Assessment Flashcards
What diagnostic testing is done to evaluate sleep?
PSG (in lab/HST) Actigraphy Sleep diary MSLT MWT
Sleep diary uses and what info is collected?
Consensus sleep diary (standardized by Carney)
Use for insomnia & circadian rhythm disorders
Time in bed, lights out, WASO, morning wake time, time awake too early
Caffeine and alcohol use
sleep aid use
Multiple sleep latency test (MSLT)
Purpose: standard measure for objective sleepiness, differential dx
Protocol:
5 nap opportunities scheduled at 2hr starting 1.5-3 hrs from end of PSG
Used to see extent of EDS
Instructions: “try to fall asleep”
Nap session is terminated after 20 min
What are other considerations when doing MSLT?
Preceded by nocturnal PSG (>6 hrs TST)
Ideally, no medications for 2 weeks (i.e. stimulants)
Ideally, scheduled at patient’s typical sleep/wake schedule
What is the findings with positive MSLT?
Patient falls asleep with a MSL < 8 min in the naps
Had at least no more than 1 nap (for IH) or 2 naps (for narcolepsy) where REM sleep was reached
Maintenance of Wakefulness Test (MWT)
Purpose: measures the ability to stay awake, often used to evaluate response to Tx
Protocol:
4 trials at 2 hr intervals
Instructions: “remain awake for as long as possible”
Trials end after 40 min. If no sleep
Considerations:
PSG prior to MWT?
unclear if MWT generalizes to occupations safety
Actigraphy monitoring devices (FitBit, Garmin, etc.)
Quantifying movement over time
Accelerometer that measures special displacement
Values use to compute values for epochs of (usually) 1 min
average or max movement
What does monitoring devices contain?
Piezoelectric accelerometer
Low pass filter that excludes external vibrations
Data storage and computation:
proportional integral mode measures area under the curve of the waveform
zero-crossing mode counts the number of times the waveform crosses 0 per epoch
Time above threshold measures the amount of time that the activity is above a minimum
Actigraphy for sleep
Inference of sleep and wake from lib movement Advantages over PSG: less expensive highly portable more convenient 24 hr recordings Record multiple days
What is the history of actigraphy for sleep monitoring?
1972 first report using
More portable systems Kupfer et al 1977
1989 first automatic scoring algorithms
2001 Jean-Louis, Ripken, cole algorithms for day vs night, old vs young, etc.
How well does actigraphy measure sleep?
Agreement with PSG- high correlations, .8-.9
Some new devices might not perform as well
Scoring algorithm
Cole-Kripke scoring algorithm (math formula and follow up rules)
Formula=D=wake/sleep (<1=sleep)
Examines activity recording of current min, plus 4 min. Before and 2 min. After
Applies weight to each
Follow up rules
If you have 4-9 min. Of wake, recode 1st min of sleep to wake
If you have 10-14 min of wake, first 3 sleep should be wake
What are controversies of actigraphy?
Sleep latency can be difficult
Overestimate WASO
Does not measure sleep stages, including REM
Some people overestimate measure of sleep
It’s a method for ESTIMATING sleep, just like PSG and sleep diaries
Actigraphy can be problematic in special populations
Actigraphy need to be recalibrated (ideally every year)
All actigraphy are not the same
Does not have sleep architecture
Most useful for characterizing sleep patterns
Useful for sleep disorders, particularly insomnia
What does the initial evaluation include?
The Clinic workup
Gender (F>M) and age (> older adults)
Sleep complaints (insomnia symptoms)
Time course, severity, progression
Daytime symptoms
Prior treatment attempts (hypnotics, OTCs)
Sleep habits (napping, irregular S/W schedule, long TIB)
Sleeping environment (TV/phone in bed, noisy, not dark)
Dysfunctional cognitions (sleep and wake related)
Think “comorbidity”:
medical/psychiatric factors
substance use/abuse (caffeine, nicotine, ETOH)
sleep diary (standardized forms available from Sleep consensus paper, Carney et. Al, sleep 2012)
Possibly wrist actigraphy
PSG not routinely done (yes if possible OSA or Tx failure)
Functional analysis
Behavior analysis=the scientific study of those interactions between individuals and their environment responsible for behavior change
Identify and quantify the causal and outcome variables in the behavior change process
What are the psychometric assessment tools?
Subjective measures for sleep quality, daytime sleepiness and functional outcomes
Pittsburgh Sleep Quality Index (PSQI)
PROMIS sleep disturbance
Epworth Sleepiness Scale (ESS)
Functional Outcomes of Sleep Questionnaire
