Core Concepts & Fundamentals Flashcards

What is the AASM-defined minimum frequency for activity to qualify as a sleep spindle?

Answer: 11 Hz

AASM defines sleep spindles as bursts of 11–16 Hz activity lasting 0.5–3 seconds.

Which of the following is the correct electrode derivation used to record the central EEG in standard PSG per AASM?

Answer: C4-M1

AASM recommends C4-M1 (with backup C3-M2) as the central EEG derivation for sleep staging.

Slow-wave sleep (SWS) consists of which AASM sleep stage(s)?

Answer: N3 only

Under AASM guidelines, Stage N3 is equivalent to slow-wave sleep (formerly stages 3 and 4 combined).

An arousal in PSG is defined as an abrupt shift in EEG frequency lasting at least how long?

Answer: 3 seconds

AASM defines an arousal as an abrupt EEG frequency shift lasting at least 3 seconds, preceded by at least 10 seconds of sleep.

What does the term 'hypnogram' represent in polysomnography?

Answer: A chart showing sleep stage progression across the recording period

A hypnogram is a visual summary graph plotting sleep stages on the Y-axis against time on the X-axis across the recording.

According to AASM rules, how much NREM sleep must precede a scored arousal?

Answer: 10 seconds

At least 10 consecutive seconds of sleep must precede an EEG frequency shift for it to be scored as an arousal.

Which sleep stage typically has the highest threshold for arousal by external stimuli?

Answer: Stage N3

Stage N3 (slow-wave sleep) has the highest arousal threshold, making it the most difficult stage from which to awaken someone.