Copyright Compumedics Limited Sleep Staging Basics Copyright Compumedics Limited
Copyright Compumedics Limited The following presentation is being provided for informational and educational purposes only. While Compumedics endeavors to ensure the validity and accuracy of the information within, we cannot be held responsible for inaccuracies, opinions or practices that often vary between various experts or are without established acceptable medical standards. Please consult your own medical director for clarification or for policies that are specific to your facility. We welcome your comments, suggestions and corrections. Please e-mail your comments to: marketing@compumedics.com.au Copyright Compumedics Limited
Sleep Staging Variables Electroencephalogram (EEG) - acquired by surface electrodes on the scalp at standardized locations (10-20 system) Electrooculogram (EOG) - acquired by surface electrodes placed at the outer canthus of each eye Electromyogram (EMG) - acquired by surface electrodes placed on the chin muscle (sub-mental) Copyright Compumedics Limited
Sleep Staging Channels Copyright Compumedics Limited
Copyright Compumedics Limited EEG Frequency and amplitude change with sleep stage: Wake: high frequency Stage N1and REM: low amplitude, mixed frequency (vertex waves may be in N1) Stage N2: spindles, k-complexes Stage N3: delta waves (≥ 75 uV, ≤ 2 Hz) Standard sleep epoch is 30 seconds Copyright Compumedics Limited
Copyright Compumedics Limited EOG EOG records voltage changes caused by eye movement; EOG changes with sleep stage Wake: random, high amplitude: Stage 1: slow rolling: REM: very flat with occasional rapid eye movements: Copyright Compumedics Limited
Copyright Compumedics Limited EMG Recorded as the potential between two surface electrodes placed several centimeters apart Typically, the chin (submental) muscle is used because it exhibits large differences during sleep, aiding in the identification of stages Wake - high activity Sleep - lower activity REM sleep - paralysis of skeletal muscles Copyright Compumedics Limited
Copyright Compumedics Limited Sleep Stage Criteria ALPHA WAVES Awake Alpha or faster > 50% of epoch Many eye movements High EMG Stage N1 Alpha or faster < 50 % of epoch Increasing theta activity Slow rolling eyes Vertex sharp waves THETA WAVES VERTEX WAVE Copyright Compumedics Limited
Sleep Staging Criteria Stage N2 Sleep Spindles 12-14 cps 0.5 second duration or longer and/or K-complexes Sharp negative deflection followed by nearly equal positive deflection At least 0.5 seconds in duration Sleep Spindle K-complex Copyright Compumedics Limited
Sleep Staging Criteria Stage N3 - Delta Waves (≥75uV) ≥ 20% of epoch DELTA WAVES Copyright Compumedics Limited
Sleep Staging Criteria REM Lowest EMG Rapid Eye Movements (REMs) Saw-tooth EEG Low-amplitude, mixed frequency EEG similar to stage 1 Copyright Compumedics Limited
Copyright Compumedics Limited Stage: Awake Copyright Compumedics Limited
Copyright Compumedics Limited Stage N1 Sleep Copyright Compumedics Limited
Copyright Compumedics Limited Stage N2 Sleep Copyright Compumedics Limited
Copyright Compumedics Limited Stage N3 Sleep Copyright Compumedics Limited
Copyright Compumedics Limited Stage REM Sleep Copyright Compumedics Limited
Copyright Compumedics Limited Stage REM Sleep Sawtooth waveform pattern seen in REM sleep. Copyright Compumedics Limited
Copyright Compumedics Limited Infant Sleep Patterns Circadian rhythm not established prior to week 10 or 11 from birth. Consolidation of sleep usually occurs by week 16-17. Between 24-36 weeks Active-Quiet Sleep pattern is established. At 5-6 months R&K rules can be applied. Age is corrected for normal gestational age. Copyright Compumedics Limited
Changing Sleep Patterns With Age Copyright Compumedics Limited
Copyright Compumedics Limited Active Sleep - Infant Continuous cycling of wakefulness-active sleep (REM) and quiet sleep(NREM). Sleep onset is usually to active sleep (REM) Mixed, low-voltage, irregular EEG Suppressed EMG Intermittent REMs Frequent muscle twitches and body movements Copyright Compumedics Limited
Copyright Compumedics Limited Active Sleep - Infant Copyright Compumedics Limited
Copyright Compumedics Limited Quiet Sleep - Infant High voltage, slow-wave EEG activity Trace alternant, 3-8 sec. burst of high voltage slow waves, alternating with 4-8 seconds of low voltage mixed freq. waves EMG tonic Eye movements absent Minimal body movement Copyright Compumedics Limited
Copyright Compumedics Limited Quiet Sleep - Infant Copyright Compumedics Limited
Copyright Compumedics Limited Infant Sleep Staging Wake, Active (REM) Sleep, Quiet (NREM) Sleep, Indeterminate, Movement or Artifact. If an epoch can not be staged as Wake, Active or Quiet, it is Indeterminate. Crying is considered awake. Artifact is scored if one minute or more of recording is unscorable. Copyright Compumedics Limited