Complete Questions with Verified Answers
& Explanations
Question 1
An adult patient's polysomnogram shows a sudden cessation of airflow for 12
seconds. During this entire 12-second period, there is a complete absence of chest and
abdominal wall movement in the respiratory inductance plethysmography (RIP)
channels. What is the correct classification of this event?
A) Obstructive Apnea
B) Central Apnea
C) Mixed Apnea
D) Hypopnea
Verified Answer: B) Central Apnea
Explanation: According to standard AASM scoring criteria, an apnea is classified
as central if it meets the airflow reduction criteria (a drop in the peak signal
excursion by ≥ 90% from the pre-event baseline using an oronasal thermal sensor)
for a minimum duration of 10 seconds, and is characterized by a complete absence
of respiratory effort throughout the entire duration of the event.
,Question 2
During a standard 10-20 international electrode placement setup, the technologist
measures the distance from the nasion to the inion to be 40 cm. What is the correct
distance from the nasion to the Fz electrode site?
A) 4 cm
B) 8 cm
C) 12 cm
D) 20 cm
Verified Answer: C) 12 cm
Explanation: In the 10-20 international system, the longitudinal measurements
from the nasion are calculated as follows: Fp is 10% of the total distance from the
nasion, Fz is an additional 20% past Fp (totaling 30% from the nasion), Cz is 50%,
Pz is 70%, and Oz is 90%. Therefore, 30% of 40 cm is calculated as 0.30 × 40 = 12
cm.
Question 3
While monitoring a diagnostic study, the technologist notices a rhythmic, sharp
artifact occurring simultaneously across all EEG and EOG channels. The artifact is
perfectly synchronized with the patient’s R-wave on the electrocardiogram channel.
What is the best method to eliminate or minimize this artifact?
A) Change the high-frequency filter (HFF) of the EEG channels from 35 Hz to 15 Hz.
B) Re-reference the affected channels to a backup explorer electrode (e.g., M1 or M2)
or link the mastoids.
,C) Ask the patient to turn off their cell phone or other portable electronic devices.
D) Warm the patient's room to prevent shivering.
Verified Answer: B) Re-reference the affected channels to a backup explorer
electrode (e.g., M1 or M2) or link the mastoids.
Explanation: ECG artifact occurs when an electrode is placed directly over a
superficial blood vessel or when there is a significant potential difference relative to
the reference electrode. Re-referencing to an alternative mastoid node or combining
references helps cancel out the common in-phase cardiac signal. Altering filters will
not eliminate this frequency range without distorting the underlying sleep
architecture signals.
Question 4
According to the AASM Manual for the Scoring of Sleep and Associated Events, what
is the minimum amplitude and frequency requirement for a waveform to be
considered a K-complex?
A) A sharp negative wave followed by a slower positive component, with a total
duration ≥ 0.5 seconds, and no amplitude requirement.
B) A biphasic wave lasting between 0.1 and 0.2 seconds with a minimum amplitude of
75 μV.
C) A sharp negative deflection followed by a positive deflection, with a total duration
≥ 0.5 seconds, independent of amplitude, but typically prominent.
D) A triphasic wave lasting at least 1.0 second with a minimum amplitude of 50 μV.
Verified Answer: C) A sharp negative deflection followed by a positive deflection,
with a total duration ≥ 0.5 seconds, independent of amplitude, but typically
prominent.
Explanation: The AASM defines a K-complex as a well-delineated, negative sharp
wave immediately followed by a slower positive component. The total duration of the
, entire complex must be ≥ 0.5 seconds. While they are characteristically high in
voltage, the formal definition does not mandate a strict minimum amplitude
threshold, unlike delta waves.
Question 5
During CPAP titration, a patient with a history of severe obstructive sleep apnea is
titrated to 10 cm H₂O. The obstructive apneas disappear, but the patient suddenly
develops frequent, repetitive central apneas meeting criteria. What is the most likely
clinical phenomenon occurring?
A) Severe Upper Airway Resistance Syndrome (UARS)
B) Complex Sleep Apnea Syndrome (Treatment-Emergent Central Sleep Apnea)
C) REM-Related Hypoventilation
D) Obesity Hypoventilation Syndrome (OHS)
Verified Answer: B) Complex Sleep Apnea Syndrome (Treatment-Emergent Central
Sleep Apnea)
Explanation: Treatment-Emergent Central Sleep Apnea (historically called
Complex Sleep Apnea) is characterized by the resolution of obstructive respiratory
events followed by the emergence or significant worsening of central apneas or
Cheyne-Stokes breathing during the application of CPAP or bilevel positive airway
pressure without a backup rate.
Question 6
Which of the following describes the correct filter settings for recording standard
electromyography (EMG) channels, such as the chin or submental EMG, in