RPSGT RPSGT Sleep Staging & Scoring 1 — Questions and Answers
Question 1: According to AASM scoring rules, what percentage of an epoch must consist of slow wave activity to score Stage N3?
- ≥10%
- ≥20% (Correct answer)
- ≥30%
- ≥50%
Correct answer: ≥20%
AASM rules require that ≥20% of the epoch consist of slow wave activity (0.5–2 Hz, >75 µV frontal) to score Stage N3.
Question 2: What is the typical frequency range for sleep spindles used when scoring Stage N2?
- 4–7 Hz
- 8–10 Hz
- 11–16 Hz (Correct answer)
- 18–25 Hz
Correct answer: 11–16 Hz
Sleep spindles are defined as 11–16 Hz (typically 12–14 Hz) waxing-and-waning activity lasting ≥0.5 seconds.
Question 3: What is the minimum duration a K-complex must meet to satisfy AASM scoring criteria?
- 0.25 seconds
- 0.5 seconds (Correct answer)
- 0.75 seconds
- 1.0 second
Correct answer: 0.5 seconds
AASM requires a K-complex to have a total duration of ≥0.5 seconds.
Question 4: According to AASM guidelines, which electrode region is used to measure slow wave activity for N3 scoring?
- Occipital (O1/O2)
- Central (C3/C4)
- Frontal (F3/F4) (Correct answer)
- Temporal (T3/T4)
Correct answer: Frontal (F3/F4)
AASM specifies that slow wave activity amplitude and percentage are assessed over frontal derivations (F3 or F4).
Question 5: What is the standard epoch length used in polysomnography scoring per AASM guidelines?
- 20 seconds
- 30 seconds (Correct answer)
- 45 seconds
- 60 seconds
Correct answer: 30 seconds
The standard PSG epoch length is 30 seconds, established by Rechtschaffen & Kales and retained in AASM rules.
Question 6: During REM sleep, which chin EMG finding is expected on a polysomnogram?
- High-amplitude tonic activity
- Moderate activity with phasic bursts
- Atonia with occasional phasic twitches (Correct answer)
- Rhythmic jaw clenching
Correct answer: Atonia with occasional phasic twitches
REM sleep is characterized by chin EMG atonia (the lowest amplitude relative to other stages) with occasional phasic muscle twitches.
Question 7: According to AASM rules, an epoch is scored Stage Wake (W) when alpha activity occupies what proportion of the epoch?
- ≥20%
- ≥30%
- ≥50% (Correct answer)
- ≥75%
Correct answer: ≥50%
Stage W is scored when alpha activity is present for ≥50% of the epoch in subjects who generate occipital alpha.
RPSGT RPSGT Sleep Staging & Scoring 1
According to AASM scoring rules, what percentage of an epoch must consist of slow wave activity to score Stage N3?