Part I. Polysomnography

What is Polysomnography? Stimultaneously recording of numerous physiological variables during sleep: EEG, EOG, EMG, EKG, airflow, respiratory efforts, O 2 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 is performed

Parameters of Routine PSG EEG (C 3 /A 2, C 4 /A 1, O 1 /A 2, O 2 /A 2 ) EOG (ROC/A 1, LOC/A 2 ) EMG (chin & anterior tibialis) EKG Nasal and oral airflow Thoracic and abdominal respiratory efforts O 2 saturation

EMG (chin & anterior tibialis) - periodic leg moments; PLMs

Summary: Role in Clinical Decision Making 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 : Role in Recearch 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 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 / 전체수면시간ⅹ 60

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 과 흉부의 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

The Consequences of Severe Sleepiness Microsleeps Inability to read/study Accidents (especially driving) Memory problems Failure in school/at work

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 C 3 /A 2 or C 4 /A 1, O 1 /A2 or O 2 /A 1 ROC/A 1, LOC/A 2, 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 낮잠시간수면잠복기 ( 불을 끈 후 잠들 때까지 의 시간 ) 입면기 렘수면 ( 잠이 든 후 15 분 이내에 렘수면이 출현하는 것 ) 환자의 주관적 평가 잠이 들었습 니까 ? 꿈을 꾸었습 니까 ? 9:00am0.5 분 YesNo 11:00am2분2분 Yes 1:00pm3분3분 Yes 3:00pm3분3분 NoYesNo 5:00pm1.5 분 Yes 평균 2분2분 4회4회

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 - Mean MSLT of less than 5min & SOREMPs of more than 2 are diagnostic of narcolepsy

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