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 10 초이상 호흡이 정지되는 경우를 말하며 동맥혈내 산소포화도의 감소 , 부정맥등이 동반되어 나타나며 수면효율의 저하로 주간의 과도한 졸리움 , 기억력 저하 및 집중력 저하등의 증상이 나타난다

• Apnea index = 무호흡수 /전체수면시간ⅹ 60• 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 복벽 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

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 보고서낮잠시간 수면잠복기

( 불을 끈 후 잠들

때까지의 시간 )

입면기 렘수면 ( 잠이 든 후 15

분이내에 렘수면이

출현하는 것 )

환자의 주관적 평가잠이

들었습니까 ?꿈을

꾸었습니까 ?

9:00am 0.5 분 Yes No No

11:00am

2 분 Yes Yes Yes

1:00pm 3 분 Yes Yes Yes

3:00pm 3 분 No Yes No

5:00pm 1.5 분 Yes Yes Yes

평균 2 분 4 회

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