RPSGT Best Practices & Methodologies 4

Question 1

Which EEG feature is required to score an epoch as stage N2 sleep?

Accepted Answer

At least one K-complex or sleep spindle in the absence of arousal

Answer

Stage N2 requires one or more K-complexes or sleep spindles not associated with arousal, in the absence of sufficient slow-wave activity for N3.

Question 2

Stage N3 is scored when high-amplitude slow-wave activity occupies what proportion of an epoch?

Accepted Answer

>20%

Answer

N3 (slow-wave sleep) is scored when ≥20% of the epoch contains waves with frequency 0.5–2 Hz and peak-to-peak amplitude >75 µV.

Question 3

REM sleep is identified by which combination of polysomnographic features?

Accepted Answer

Low-amplitude mixed-frequency EEG, low chin EMG tone, and rapid eye movements

Answer

REM sleep is characterized by low-amplitude mixed-frequency EEG, atonic (low) chin EMG, and rapid eye movements.

Question 4

According to AASM rules, an arousal during NREM sleep is scored when there is an abrupt shift in EEG frequency lasting at least how long?

Accepted Answer

3 seconds

Answer

A NREM arousal requires an abrupt EEG frequency shift lasting ≥3 seconds, preceded by at least 10 seconds of stable sleep.

Question 5

What EEG waveform defines stage N1 sleep in patients who generate a well-defined alpha rhythm while awake?

Accepted Answer

Replacement of alpha rhythm by low-amplitude mixed-frequency activity

Answer

In patients with alpha rhythm, N1 is scored when alpha is attenuated and replaced by low-amplitude mixed-frequency (predominantly 4–7 Hz) EEG activity.

RPSGT Exam Practice Test

RPSGT Exam Practice Test

RPSGT Best Practices & Methodologies 4