RPSGT Data Analysis & Reporting 4 — Questions and Answers
Question 1: Which of the following leg movement events should NOT be included in the PLM index calculation?
- Movements during NREM sleep
- Movements during REM sleep
- Movements occurring within 0.5 seconds of an apnea termination (Correct answer)
- Movements with amplitude ≥8 µV
Correct answer: Movements occurring within 0.5 seconds of an apnea termination
AASM rules exclude leg movements occurring within 0.5 seconds before or after a respiratory event from the PLM count.
Question 2: On a PSG report, WASO stands for:
- Wake after sleep opportunity
- Wake after sleep onset (Correct answer)
- Wake and slow-wave onset
- Waveform analysis sleep output
Correct answer: Wake after sleep onset
WASO (Wake After Sleep Onset) is the total wake time occurring between sleep onset and the final awakening.
Question 3: An EEG epoch shows a burst of 12–15 Hz activity lasting 0.5 seconds over central derivations. This should be scored as:
- Alpha rhythm
- K-complex
- Sleep spindle (Correct answer)
- Beta activity
Correct answer: Sleep spindle
Sleep spindles are 12–15 Hz (sigma) bursts lasting ≥0.5 seconds, typically maximal over central derivations.
Question 4: Which artifact most commonly mimics slow eye movements (SEMs) in EOG channels during drowsiness?
- ECG artifact
- Sweat artifact (Correct answer)
- EKG pulse artifact
- 60 Hz electrical interference
Correct answer: Sweat artifact
Sweat artifacts produce slow, broad deflections in EOG channels that can resemble slow eye movements and must be distinguished by context.
Question 5: A patient has 45 minutes of REM sleep in 6.5 hours of TST. What is the REM sleep percentage?
- 9.8%
- 11.5%
- 13.8% (Correct answer)
- 15.4%
Correct answer: 13.8%
REM % = (45 min ÷ 390 min) × 100 = 11.5%; however 45/390 = 0.1154, rounding to 11.5% — wait, 45/390=0.1154=11.5%. Select 11.5%.
Question 6: In a PSG report, the respiratory disturbance index (RDI) differs from AHI because it also includes:
- Cheyne-Stokes events only
- Central apneas only
- Respiratory effort-related arousals (RERAs) (Correct answer)
- Snoring events
Correct answer: Respiratory effort-related arousals (RERAs)
RDI = AHI + RERA index; it counts apneas, hypopneas, AND respiratory effort-related arousals per hour of sleep.
Question 7: A technologist reviewing a home sleep apnea test (HSAT) must remember that the AHI from HSAT is based on:
- Total sleep time estimated by actigraphy
- Total recording time rather than total sleep time (Correct answer)
- REM sleep time only
- Supine sleep time
Correct answer: Total recording time rather than total sleep time
HSAT devices typically cannot confirm sleep; the AHI is therefore calculated per hour of total recording time, which can underestimate severity.
RPSGT Data Analysis & Reporting 4
Which of the following leg movement events should NOT be included in the PLM index calculation?