Part I. Polysomnography
What is Polysomnography?
• Stimultaneous recording of numerous
physiological variables during sleep:
EEG, EOG, EMG, EKG, airflow,
respiratory efforts, O2 saturation, etc.
• Serves as a diagnostic tool for
evaluation of normal and disturbed
sleep
• Monitoring by a trained technologist
Laboratory Equipment
• Eliminate the influence of
environmental stimuli (noise, light,
temperature)
• Comfortable bed
• Infrared light source and a low light
video camera system
Patient preparation
• Maintain a regular sleep-wake rhythm
• Avoid sleeping pills or narcotics several days
before the study
• Avoid strenuous physical exercise on the day
of the study
• Not to drink coffee, tea, or alcoholic
beverages
• After a light meal, using toilet, and
appropriate dressing, hook-up is performed
Parameters of Routine PSG
• EEG (C3/A2, C4/A1, O1/A2, O2/A2)
• EOG (ROC/A1, LOC/A2)
• EMG (chin & anterior tibialis)
• EKG
• Nasal and oral airflow
• Thoracic and abdominal respiratory efforts
• O2 saturation
EMG (chin & anterior tibialis)
- periodic leg moments; PLMs
Summary
• PSG is the most important tool for
evaluation of sleep disorders
• PSG is essential to Dx of OSA & PLMD
• Findings of PSG should be interpreted
within clinical context
Summary
• Major break-through in sleep research
• PSG plays important role in scientific
investigation of normal physiology of
sleep & study of mechanisms of disease
and their treatment
수면 무호흡증
• 코골이가 심할 경우, 수면중 약 10초이상 호흡이 정지
되는 경우를 말하며 동맥혈내 산소포화도의 감소 , 부
정맥등이 동반되어 나타나며 수면효율의 저하로 주간
의 과도한 졸리움, 기억력 저하 및 집중력 저하등의 증
상이 나타난다
• Apnea index = 무호흡수/전체수면시간ⅹ60
• 무호흡지수가 5 이하인 경우 정상
1)중추성 무호흡증(Central sleep apnea syndrome)
: 모든 호흡진행이 뇌와 중추장애로 중지된다.
2)폐쇄성 무호흡증(Obstructive sleep apnea syndrome)
: 상기도의 후두부의 폐쇄가 원인이며, 공기의 흐름이 막혀도 복
벽 과흉부의 움직임으로 호흡을 계속해서 시도한다.
3)혼합성 무호흡증(Mixed sleep apnea syndrome)
: 위의 두 가지가 혼합되어 나타나는 무호흡이다.
Part II. The Clinical Use of
the Multiple Sleep Latency
Test
Indications for the MSLT
• Narcolepsy
• Obstructive sleep apnea syndrome
• Other causes of excessive sleepiness
(idiopathic hypersomnia, PLMD, etc.)
• Insomnia
• Circadian rhythm sleep disorders
• Assessment of treatment effects
General Considerations for MSLT
•
•
•
•
•
•
•
1~2 weeks of sleep diaries preceding MSLT
Following all-night PSG on habitual schedule
Careful consideration of drug schedule
Skilled, rested PSG technologist
Dress in street clothes before MSLT
Quiet, dark, temperature-controlled room
No alcohol or caffeine
General Considerations for
MSLT
• It measures latency to sleep onset and
confirms sleep onset REM period (SOREMP)
• It is administered 5 times per day at 2-h
intervals with no intervening sleep or
stimulants
• Basic underlying assumption
-increased sleep latency
= decreased sleepiness
-decreased sleep latency
= increased sleepiness
Recording Montage for MSLT
•
•
•
•
•
C3/A2 or C4/A1, O1/A2 or O2/A1
ROC/A1, LOC/A2,
EMG (chin)
EKG
Airflow, CPAP, respiratory sounds
Scoring MSLT
• Sleep latency ; elapsed time from
light-out to the first epoch scored as
sleep
• Presence or absence of REM sleep
within 15 min after sleep-onset
MSLT 결과 보고서
낮잠시간
수면잠복기
(불을 끈 후
잠들 때까지
의 시간)
입면기 렘수면
(잠이 든 후 15분
이내에 렘수면이
출현하는 것)
9:00am
0.5분
11:00am
환자의 주관적 평가
잠이 들었습
니까?
꿈을 꾸었습
니까?
Yes
No
No
2분
Yes
Yes
Yes
1:00pm
3분
Yes
Yes
Yes
3:00pm
3분
No
Yes
No
5:00pm
1.5분
Yes
Yes
Yes
평균
2분
4회
Severity of sleepiness
• Mild sleepiness
; MSLT mean sleep latency of 10~15min
• Moderate sleepiness
; MSLT mean sleep latency of 5~10min
• Severe sleepiness
; MSLT mean sleep latency of less than 5min
-> pathological daytime sleepiness
Interpretation of MSLT
• Mean MSLT of less than 5min &
SOREMPs of more than 2 are
diagnostic of narcolepsy
• Medical judgement rather than
absolute test scores must weigh
significantly in interpretations
Summary
• ES is a potentially life-threatening condition
• MSLT is the only scientifically validated
objective test
• MSLT helps establish the Dx of ES
disorders such as narcolepsy
• MSLT is useful for determining sleepiness
severity
• However, MSLT may produce false-negative
results