RPSGT Electroencephalography & Signal Interpretation Flashcards

The epoch length recommended by AASM for adult PSG sleep scoring is:

Answer: 30 seconds

AASM guidelines specify 30-second epochs as the standard unit for adult polysomnographic sleep staging, retained from the original Rechtschaffen and Kales manual.

Vertex sharp waves (V waves) are associated with which sleep stage?

Answer: N1 sleep

Vertex sharp waves are high-amplitude biphasic waveforms maximal at the central (Cz) electrode that appear during N1 sleep, often in response to external stimuli.

An EEG arousal during PSG is scored when there is an abrupt EEG frequency shift lasting at least:

Answer: 3 seconds

AASM defines an EEG arousal as an abrupt shift to alpha, theta, or >16 Hz activity lasting ≥3 seconds, preceded by ≥10 seconds of stable sleep.

Positive occipital sharp transients of sleep (POSTS) are normal EEG variants that occur during which stages?

Answer: N1 and N2 sleep

POSTS are triangular, surface-positive sharp waves at occipital electrodes that are benign normal variants occurring during N1 and N2 NREM sleep.

Mixed frequency low-amplitude EEG combined with low chin EMG tone defines which sleep stage?

Answer: REM

REM sleep is identified by mixed frequency low-amplitude EEG resembling wakefulness, combined with low chin EMG tone and often rapid eye movements.

Phasic chin muscle activity (transient muscle activity) during REM is scored when bursts last:

Answer: 0.25–0.5 seconds

AASM defines phasic chin EMG bursts during REM as lasting 0.25–0.5 seconds with amplitude at least 4× the background EMG level.