EEG Sleep Staging and Sleep EEG 3

Question 1

An EEG epoch scored as REM typically shows all of the following EXCEPT:

Accepted Answer

Sleep spindles

Answer

Sleep spindles are a feature of NREM (N2) sleep and are absent during REM sleep; REM is defined by low-voltage mixed EEG, rapid eye movements, and muscle atonia.

Question 2

Alpha intrusion into NREM sleep (alpha-delta sleep) is associated with:

Accepted Answer

Non-restorative sleep and fibromyalgia

Answer

Alpha-delta sleep, where alpha activity intrudes into slow-wave sleep, is linked to non-restorative sleep and is commonly described in fibromyalgia patients.

Question 3

In polysomnography scoring, an arousal is defined as an abrupt EEG frequency shift lasting at least:

Accepted Answer

3 seconds

Answer

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

Question 4

Which normal EEG variant appearing at sleep onset consists of brief 4–6 Hz runs with a positive polarity at the vertex?

Accepted Answer

Hypnic jerks with associated vertex potentials

Answer

Hypnic jerks are sudden body twitches at sleep onset that correlate with brief vertex-maximal EEG potentials and are a normal physiologic phenomenon.

Question 5

The EEG technologist notes the patient's EEG shows continuous delta slowing only in the posterior head regions during deeper NREM sleep. This is most consistent with:

Accepted Answer

Normal occipital delta of sleep

Answer

Occipital delta waves during deep NREM sleep are a normal finding and should not be interpreted as pathological posterior slowing.

EEG - Electroencephalography Practice Test

EEG - Electroencephalography Practice Test

EEG Sleep Staging and Sleep EEG 3