basics of sleep staging-09

8/3/2019 Basics of Sleep Staging-09

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Sleep Staging Basics

Copyright 2009 Compumedics Ltd.


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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 varybetween 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: [email protected]



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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)



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Sleep Staging Channels



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EEG

Frequency and amplitude change with sleep stage:

Wake: high frequency

Stage N1and REM: low amplitude, mixedfrequency (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



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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:



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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



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Sleep Stage Criteria

Awake

Alpha or faster > 50% of

epoch

Many eye movements

High EMG

Stage N1

Alpha or faster < 50 % ofepoch

Increasing theta activity

Slow rolling eyes

Vertex sharp waves

ALPHA WAVESALPHA WAVES

THETA WAVESTHETA WAVES

VERTEX WAVEVERTEX WAVE



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Sleep Staging Criteria Stage N2

Sleep Spindles

12-14 cps 0.5 second duration orlonger

and/or

K-complexes

Sharp negative deflection

followed by nearly equalpositive deflection

At least 0.5 seconds induration

Sleep SpindleSleep Spindle

K-complexK-complex



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Sleep Staging Criteria

Stage N3 - Delta Waves (75uV) 20%

of epoch

DELTA WAVESDELTA WAVES



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Sleep Staging Criteria REM

Lowest EMG

Rapid Eye Movements (REMs) Saw-tooth EEG

Low-amplitude, mixed frequency EEG similarto stage 1



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Stage: Awake



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Stage N1 Sleep



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Stage N2 Sleep



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Stage N3 Sleep



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Stage REM Sleep



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Stage REM Sleep

Sawtooth waveform pattern seen in REM sleep.



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Infant Sleep Patterns

Circadian rhythm not established prior to week 10 or 11from birth.

Consolidation of sleep usually occurs by week 16-17.

Between 24-36 weeks Active-Quiet Sleep pattern isestablished.

At 5-6 months R&K rules can be applied.

Age is corrected for normal gestational age.



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Changing Sleep Patterns With Age



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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, irregularEEG

Suppressed EMG

Intermittent REMs Frequent muscle twitches and body movements



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Active Sleep - Infant



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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



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Quiet Sleep - Infant



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Infant Sleep Staging

Wake, Active (REM) Sleep, Quiet (NREM) Sleep,

Indeterminate, Movement orArtifact.

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.


basics of sleep staging-09

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