RPSGT Electroencephalography & Signal Interpretation Flashcards

According to AASM scoring rules, which EEG electrode derivations are used for adult sleep staging?

Answer: F4-M1, C4-M2, and O2-M1

AASM recommends three EEG derivations (F4-M1, C4-M2, O2-M1) with contralateral backup electrodes to capture activity from frontal, central, and occipital cortical regions.

K-complexes are most prominently identified in which EEG derivation?

Answer: Frontal (F3/F4)

K-complexes are generated in the frontal cortex and are best visualized in frontal EEG derivations (F3/F4), though they are visible across channels.

Alpha rhythm is defined as EEG activity in the frequency range of:

Answer: 8–13 Hz

Alpha activity is defined as EEG oscillations between 8–13 Hz, predominantly seen in occipital derivations during relaxed wakefulness with eyes closed.

Sleep spindles are generated primarily by which brain structure?

Answer: Thalamus

Sleep spindles are generated by thalamocortical circuits, with the thalamic reticular nucleus acting as the pacemaker for the 12–15 Hz oscillations.

Which EEG waveform, when occupying ≥20% of a 30-second epoch, defines N3 (slow-wave) sleep?

Answer: Delta waves (0.5–2 Hz, >75 µV amplitude)

N3 sleep is scored when high-amplitude delta waves (>75 µV, 0.5–2 Hz) occupy ≥20% of the 30-second epoch, reflecting deep slow-wave sleep.

Saw-tooth waves on EEG during PSG are characteristic of which sleep stage?

Answer: REM

Saw-tooth waves are 2–6 Hz sharply contoured, notched waveforms occurring in bursts during REM sleep, often preceding bursts of rapid eye movements.