EEG Sleep Staging and Sleep EEG

Question 1

Which EEG feature is the hallmark of Stage N2 sleep?

Accepted Answer

Sleep spindles and K-complexes

Answer

Delta waves >75 µV

Answer

Sawtooth waves

Answer

Alpha rhythm dropout

Question 2

What percentage of total sleep time must be occupied by high-amplitude delta activity to score Stage N3?

Accepted Answer

30% or more

Answer

20%

Answer

50%

Answer

10%

Question 3

Sawtooth waves during REM sleep are best described as:

Accepted Answer

Sharply notched 2–6 Hz theta waves maximal over central regions

Answer

Spindle bursts at 14 Hz

Answer

High-amplitude delta waves >75 µV

Answer

Rhythmic alpha slowing to 7 Hz

Question 4

Which sleep stage is characterized by a low-amplitude, mixed-frequency EEG without sleep spindles, K-complexes, or delta waves?

Accepted Answer

N1

Answer

N2

Answer

N3

Answer

REM

Question 5

Vertex sharp waves (V-waves) are most prominent during which sleep stage?

Accepted Answer

N1

Answer

N2

Answer

N3

Answer

REM

Question 6

Muscle atonia on polysomnography is a defining feature of which stage?

Accepted Answer

REM sleep

Answer

N1 sleep

Answer

N2 sleep

Answer

N3 sleep