1. Electroencephalography basics
for sleep study
Egypt’s early career psychiatrists (EECP) workshop
Ahmed Eid el-Aghoury
Board-certified, MScMed, MBChB
Technical training at Neurovirtual corporation, Florida, USA
al-Abbassia Hospital for mental Health, Cairo
3. Objectives
Sleep stages
Key descriptive terms of EEG
Common normal EEG pattern during
sleep and wake
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4. Analysis of polysomnogram (PSG)
The clinical interpretation of PSG is
based primarily on the analysis of 3
main variables:
1) EEG-related variables (i.e., sleep stage,
arousals)
2) Respiration-related variables (i.e.,
apneas or hypopneas)
3) Movement-related variables (i.e.,
periodic leg movements).
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7. Frequent descriptive terms
Morphology: waveform & polarity
Amplitude: voltage
Symmetry: equal amplitudes
Frequency: CPS / Hz
Synchrony: simultaneous
Rhythmicity: similar waveforms
Distribution / topography: lobes, focal, etc
Manner: continuous, intermittent, etc
Duration: in ms
Maturation: age
Reactivity: eye closing, calculation, etc
Burst: paroxysm, run or train of activity
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8. AASM Scoring Manual, 2007
Iber C, Ancoli-Israel S, Chesson A, Quan SF for the American Academy of Sleep Medicine:
The AASM Manual for the Scoring of Sleep and Associated Events: Rules, Terminology and
Technical Specifications, 1st ed. Westchester, IL: American Academy of Sleep Medicine,
2007.
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9. Sleep Stage Nomenclature
Berry R: Fundamentals of sleep medicine. 2012, Elsevier Saunders, PA
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10. Summary of Important Wave
Form Characteristics
Berry R: Fundamentals of sleep medicine. 2012, Elsevier Saunders, PA
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11. The recommended EEG derivations:
F4-M1, C4-M1, and O2-M1. (AASM, 2007)
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12. Background Activity
Syn: occipital alpha rhythm / dominant
posterior rhythm / DPR / ODR
The starting point for visual analysis
Around 10 Hz: ( 8 – 13 Hz)
Frequency milestones (maturation): eg
by age 2 ys (7 - 8 Hz )
Tested by passive eye closure
Slow & Fast variants
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14. Drowsiness
Syn: hypnagogic state
A “presleep state”, or a “prodromal or
twilight condition” between being fully
awake and asleep :
Background activity can be 1 to 2 Hz
less than that for wakefulness
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15. Drowsiness
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