RST Sleep Stage and Event Scoring Questions and Answers

Question 1

A 30-second epoch of sleep contains a clear K-complex in the first 10 seconds.
The remainder of the epoch is characterized by low-amplitude, mixed-frequency EEG, a sustained low chin EMG tone, and intermittent rapid eye movements.
How should this epoch be scored?

Accepted Answer

Stage R

Answer

Stage N2

Answer

Stage N1

Answer

Stage W

Question 2

According to the AASM Manual for the Scoring of Sleep and Associated Events, which of the following criteria must be met to score an epoch as Stage N3?

Accepted Answer

At least 20% of the epoch contains EEG activity of 2 Hz or less with peak-to-peak amplitudes of at least 75 µV.

Answer

The epoch contains at least 3 K-complexes and 2 sleep spindles.

Answer

At least 50% of the epoch contains EEG activity of 0.5 Hz or less with amplitudes of at least 50 µV.

Answer

The epoch contains at least one delta wave with a frequency of 1 Hz and an amplitude of 100 µV.

Question 3

A technologist is scoring a respiratory event and observes a >30% drop in the nasal pressure signal for 12 seconds. This event is associated with a 4% oxygen desaturation from the pre-event baseline. According to the AASM's acceptable scoring criteria, how should this event be scored?

Accepted Answer

Hypopnea

Answer

Obstructive Apnea

Answer

Respiratory Effort-Related Arousal (RERA)

Answer

Central Apnea

Question 4

Which of the following is a required criterion for scoring a series of events as Periodic Limb Movements in Sleep (PLMS)?

Accepted Answer

The duration of each limb movement must be between 0.5 and 10 seconds.

Answer

A minimum of 2 consecutive limb movements.

Answer

The period between consecutive movements must be less than 5 seconds.

Answer

The series must be associated with an oxygen desaturation of at least 3%.

Question 5

During Stage N2 sleep, a technologist observes an abrupt shift in EEG frequency to alpha activity lasting for 4 seconds. This shift is preceded by at least 10 seconds of stable sleep. How should this 4-second event be scored?

Accepted Answer

Arousal

Answer

Epoch should be rescored as Stage W

Answer

EEG artifact

Answer

Micro-sleep

Question 6

When scoring for sleep bruxism, what is the minimum required increase in chin EMG amplitude above baseline to score a phasic (rhythmic) bruxism event?

Accepted Answer

An amplitude that is at least twice the amplitude of the background EMG.

Answer

At least 10% of the maximum amplitude seen during calibration.

Answer

A sustained amplitude of at least 50 µV for 2 seconds.

Answer

An amplitude that is at least 50% greater than the amplitude during REM sleep.

A 30-second epoch of sleep contains a clear K-complex in the first 10 seconds.The remainder of the epoch is characterized by low-amplitude, mixed-frequency EEG, a sustained low chin EMG tone, and intermittent rapid eye movements.How should this epoch be scored?

A 30-second epoch of sleep contains a clear K-complex in the first 10 seconds.
The remainder of the epoch is characterized by low-amplitude, mixed-frequency EEG, a sustained low chin EMG tone, and intermittent rapid eye movements.
How should this epoch be scored?