EEG Sleep Staging and Sleep EEG 4

Question 1

Which EEG feature is pathognomonic of N2 sleep and must be present for stage scoring?

Accepted Answer

Sleep spindles or K-complexes

Answer

N2 sleep requires the presence of sleep spindles (12–14 Hz bursts) or K-complexes; delta waves define N3, sawtooth waves occur in REM, and vertex sharps mark N1.

Question 2

A patient shows repeated brief arousals out of N3 sleep in the first third of the night without awakening. This pattern is most consistent with:

Accepted Answer

Sleep terror disorder

Answer

Sleep terrors (NREM parasomnias) classically arise from N3 slow-wave sleep in the early part of the night with partial arousals and autonomic activation.

Question 3

During polysomnography, the minimum duration of a K-complex to be scored as such is:

Accepted Answer

0.5 seconds

Answer

Per AASM scoring rules, a K-complex must have a duration of ≥0.5 seconds to be distinguished from other sharp transients.

Question 4

Which of the following best describes the EEG during phasic REM sleep?

Accepted Answer

Bursts of sawtooth waves coinciding with rapid eye movements

Answer

Phasic REM is characterized by sawtooth waves (2–6 Hz, notched appearance) that typically precede or accompany bursts of REMs.

Question 5

In the AASM 2007 rules, slow-wave sleep (SWS) replaced which older Rechtschaffen & Kales (R&K) staging terminology?

Accepted Answer

Stages 3 and 4 combined into N3

Answer

The AASM 2007 manual merged R&K stages 3 and 4 into a single stage N3, collectively called slow-wave sleep.

EEG - Electroencephalography Practice Test

EEG - Electroencephalography Practice Test

EEG Sleep Staging and Sleep EEG 4