CNIM ASAP EXAM QUESTIONS
AND ANSWERS 2026 - 2027
Which of the following is a source of intraoperative physiological
artifacts?
A) Pulse
B) Blood warmer
C) Cell saver
D) Electrooculogram
A) Pulse
Which of the following may cause a temporary threshold shift of
the BAER recording?
A) CUSA
B) Cautery
C) Drill
D) Warm irrigation
C) Drill
Which of the following is the largest bio-potential source of
artifact for the BAEP?
A) Sweat
B) Pulse
C) Heart beat
D) Muscle
D) Muscle
Which of the following would most affect the ability to obtain
BAER recordings
A) Retractor
B) Inhalational gas
,C) Monopolar Coagulator
D) Pneumatic drill
C) Monopolar Coagulator
The most troublesome sources of artifact in pre-operative, pre-
induction clinical EP recordings is
A) 60Hz
B) Sweat
C) Muscle
D) Ventilation
C) Muscle
Stimulus artifact during SSEPs can be decreased by
A) Moving electrodes to a more proximal stimulation site
B) Using subdermal needle electrodes instead of sticky pads
C) Lowering the impedances of ground and stimulating electrodes
D) Increasing neuromuscular blockage
C) Lowering the impedances of ground and stimulating electrodes
When deciding between an 8ft and 20ft connector cable for a 32
channel system why is the 8ft cable preferred?
A) Decreased electrical interference
B) Impedance
C) Requires less power
D) CMRR
A) Decreased electrical interference
Why is it important to brain electrode wires in the operating
room?
A) To shorten the overall length
B) To reduce the amplifier's common mode rejection
C) To reduce interference from ambient noise
D) To avoid interfering with the surgeon's movements
,C) To reduce interference from ambient noise
How many waves of a 60Hz signal should you see in a 500ms
sweep?
A) 30
B) 12
C) 15
D) 5
Formula: # of waves = frequency x time
X = 60Hz * 0.5s = 30WAVES
How many waveforms would be present for a 60Hz artifact on a
screen with a 40msec timebase?
A) 4.8
B) 15
C) 2.4
D) 6
X= 60*0.04 = 2.4
What would be the primary precaution one should take to
decrease electrical interference in the OR?
A) using single electrode wires only when setting up the patient
B) Set up the equipment at the corner of the operating room
C) Twisting or braiding the electrode wire when setting up the
patient
D) Asking the OR nurse to unplug all electrical equipment that
are in your way
C) Twisting or braiding the electrode wire when setting up the patient
When observing a decrease in amplitude of cortical SSEPs, which
troubleshooting step could resolve this change?
A) Reposition the head
B) Increase MAP
, C) Reposition the limb
D) Discontinue intravenous agents
B) Increase MAP
Evoked Potential waveform replication criteria
A) 10% latency, 5% amplitude
B) 10% amplitude, 5% latency
C) 1% Amplitude, 15% latency
D) 1% Latency, 10% Amplitude
D) 1% Latency, 10% Amplitude
The best indicator of cerebral ischemia in CEA is seen in
A) Upper limb MEP
B) PTN SSEP
C) Lower limb MEP
D) Median nerve SSEP
D) Median nerve SSEP
During a spine procedure, if tibial nerve responses are suddenly
lost bilaterally, which of the following should be done first?
A) Perform a wake-up test
B) increase stimulus ratio
c) Increase stimulus intensity
D) Check stimulus and recording electrodes
D) Check stimulus and recording electrodes
While running upper SSEPs, your Cpc- Cpz and Cpc-Cpi
channels have good waveforms but both CPz-Cs5 channels are
rejecting all the runs. What should you do
A) Check the Cs5 electrode
B) Check the CPz electrode
C) Check the ground
D) Nothing, you only need the cortical channels
AND ANSWERS 2026 - 2027
Which of the following is a source of intraoperative physiological
artifacts?
A) Pulse
B) Blood warmer
C) Cell saver
D) Electrooculogram
A) Pulse
Which of the following may cause a temporary threshold shift of
the BAER recording?
A) CUSA
B) Cautery
C) Drill
D) Warm irrigation
C) Drill
Which of the following is the largest bio-potential source of
artifact for the BAEP?
A) Sweat
B) Pulse
C) Heart beat
D) Muscle
D) Muscle
Which of the following would most affect the ability to obtain
BAER recordings
A) Retractor
B) Inhalational gas
,C) Monopolar Coagulator
D) Pneumatic drill
C) Monopolar Coagulator
The most troublesome sources of artifact in pre-operative, pre-
induction clinical EP recordings is
A) 60Hz
B) Sweat
C) Muscle
D) Ventilation
C) Muscle
Stimulus artifact during SSEPs can be decreased by
A) Moving electrodes to a more proximal stimulation site
B) Using subdermal needle electrodes instead of sticky pads
C) Lowering the impedances of ground and stimulating electrodes
D) Increasing neuromuscular blockage
C) Lowering the impedances of ground and stimulating electrodes
When deciding between an 8ft and 20ft connector cable for a 32
channel system why is the 8ft cable preferred?
A) Decreased electrical interference
B) Impedance
C) Requires less power
D) CMRR
A) Decreased electrical interference
Why is it important to brain electrode wires in the operating
room?
A) To shorten the overall length
B) To reduce the amplifier's common mode rejection
C) To reduce interference from ambient noise
D) To avoid interfering with the surgeon's movements
,C) To reduce interference from ambient noise
How many waves of a 60Hz signal should you see in a 500ms
sweep?
A) 30
B) 12
C) 15
D) 5
Formula: # of waves = frequency x time
X = 60Hz * 0.5s = 30WAVES
How many waveforms would be present for a 60Hz artifact on a
screen with a 40msec timebase?
A) 4.8
B) 15
C) 2.4
D) 6
X= 60*0.04 = 2.4
What would be the primary precaution one should take to
decrease electrical interference in the OR?
A) using single electrode wires only when setting up the patient
B) Set up the equipment at the corner of the operating room
C) Twisting or braiding the electrode wire when setting up the
patient
D) Asking the OR nurse to unplug all electrical equipment that
are in your way
C) Twisting or braiding the electrode wire when setting up the patient
When observing a decrease in amplitude of cortical SSEPs, which
troubleshooting step could resolve this change?
A) Reposition the head
B) Increase MAP
, C) Reposition the limb
D) Discontinue intravenous agents
B) Increase MAP
Evoked Potential waveform replication criteria
A) 10% latency, 5% amplitude
B) 10% amplitude, 5% latency
C) 1% Amplitude, 15% latency
D) 1% Latency, 10% Amplitude
D) 1% Latency, 10% Amplitude
The best indicator of cerebral ischemia in CEA is seen in
A) Upper limb MEP
B) PTN SSEP
C) Lower limb MEP
D) Median nerve SSEP
D) Median nerve SSEP
During a spine procedure, if tibial nerve responses are suddenly
lost bilaterally, which of the following should be done first?
A) Perform a wake-up test
B) increase stimulus ratio
c) Increase stimulus intensity
D) Check stimulus and recording electrodes
D) Check stimulus and recording electrodes
While running upper SSEPs, your Cpc- Cpz and Cpc-Cpi
channels have good waveforms but both CPz-Cs5 channels are
rejecting all the runs. What should you do
A) Check the Cs5 electrode
B) Check the CPz electrode
C) Check the ground
D) Nothing, you only need the cortical channels
