CNIM INTRAOPERATIVE FINAL EXAMINATION
TEST 2026 FULL STUDY GUIDE WITH
SOLUTIONS
◉ If nasion to inion measures 40 cm, the distance between Fpz and Cz is
what? Answer: 16 cm
◉ To avoid a false positive, the baseline is best taken Answer: pre-
incision.
◉ During a discussion with the anesthesiologist prior to starting IONM
on a spinal correction surgery, you are informed the MDA plans to use
volatile anesthetics. Rank the volatile anesthetic agents per their MAC
values (highest to lowest). Answer: Desflurane > Sevoflurane >
Isoflurane
◉ According to ACNS guidelines, baseline data should be established:
Answer: Following positioning, but prior to surgical manipulation of
nervous system
◉ Nitrous Oxide Answer: Decreases waveform amplitude and increases
the latency of cortical responses
,◉ The highest percentage of EEG changes seen after cross clamping
during CEA happen within ______ of the cross clamp being placed.
Answer: two minutes
◉ Which of the following can increase SSEP amplitudes? Answer:
Etomidate
◉ During the monitoring of a selective dorsal rhizotomy, what muscle is
critical to monitor? Answer: Anal Sphincter
◉ If there is a 60 Hz interference in all channels when recording
preoperative median nerve SSEPs, which of the following electrodes
should be adjusted first? Answer: Ground electrode
◉ Median nerve peripheral conduction between the brachial plexus and
cervical cord is the time measured from: Answer: EP-N13
◉ Which structure is at risk during an XLIF procedure? Answer:
Lumbar plexus
◉ In recording electrocochleograms, it is best to stimulate using
Answer: rarefaction or condensation clicks.
,◉ Which of the following is most likely to cause electrical interference
for evoked potential waveforms in the operating room? Answer:
Electrocautery
◉ Which of the following would most likely be normal in the lower
extremity SSEP of a patient with a dorsal column lesion? Answer:
Popliteal Fossa Response
◉ 1 MAC of Desflurane is equivalent to a concentration of: Answer:
0.06
◉ During a median nerve preoperative study, a patient has discomfort at
the wrist. Stimulating electrodes are 10mm gold disk, stimulus intensity
is 20 mA, and stimulus duration is 100 microseconds. Which of the
following would most likely reduce the patients discomfort while
maintaining adequate stimulation? Answer: Decrease the stimulus
intensity to motor threshold
◉ To4 is used to determine which of the following values? Answer:
level of neuromuscular blockage present
◉ Which of the following is a common complication of microvascular
decompression of cranial nerve VIII? Answer: Hearing loss
, ◉ Ischemic injury of the anterior spinal artery will affect which
modality first? Answer: tcMEPs
◉ Extreme cerebellar retraction during CPA tumor surgery likely results
in: Answer: Loss of all waves due to vascular compromise
◉ Wave I of the Brainstem Auditory Evoked Potential (BAEP) has a
typical post-stimulus latency of Answer: 2 ms
◉ According to ACNS Guidelines, what is the recommended placement
of the ground for a cervical procedure? Answer: Forearm
◉ If the brachial plexus is at risk for compression due to patient
positioning, the technologist, surgeon and neurophysiologist should
discuss adding which SSEP modality to the surgical plan? Answer:
Ulnar Nerve
◉ Which of the following is most likely an anesthetic change seen in
spine cases? Answer: Changes in cortical responses in bilateral UE and
LE SSEPs
◉ Which BAER click polarity eliminates the cochlear microphonic?
Answer: Alternating
TEST 2026 FULL STUDY GUIDE WITH
SOLUTIONS
◉ If nasion to inion measures 40 cm, the distance between Fpz and Cz is
what? Answer: 16 cm
◉ To avoid a false positive, the baseline is best taken Answer: pre-
incision.
◉ During a discussion with the anesthesiologist prior to starting IONM
on a spinal correction surgery, you are informed the MDA plans to use
volatile anesthetics. Rank the volatile anesthetic agents per their MAC
values (highest to lowest). Answer: Desflurane > Sevoflurane >
Isoflurane
◉ According to ACNS guidelines, baseline data should be established:
Answer: Following positioning, but prior to surgical manipulation of
nervous system
◉ Nitrous Oxide Answer: Decreases waveform amplitude and increases
the latency of cortical responses
,◉ The highest percentage of EEG changes seen after cross clamping
during CEA happen within ______ of the cross clamp being placed.
Answer: two minutes
◉ Which of the following can increase SSEP amplitudes? Answer:
Etomidate
◉ During the monitoring of a selective dorsal rhizotomy, what muscle is
critical to monitor? Answer: Anal Sphincter
◉ If there is a 60 Hz interference in all channels when recording
preoperative median nerve SSEPs, which of the following electrodes
should be adjusted first? Answer: Ground electrode
◉ Median nerve peripheral conduction between the brachial plexus and
cervical cord is the time measured from: Answer: EP-N13
◉ Which structure is at risk during an XLIF procedure? Answer:
Lumbar plexus
◉ In recording electrocochleograms, it is best to stimulate using
Answer: rarefaction or condensation clicks.
,◉ Which of the following is most likely to cause electrical interference
for evoked potential waveforms in the operating room? Answer:
Electrocautery
◉ Which of the following would most likely be normal in the lower
extremity SSEP of a patient with a dorsal column lesion? Answer:
Popliteal Fossa Response
◉ 1 MAC of Desflurane is equivalent to a concentration of: Answer:
0.06
◉ During a median nerve preoperative study, a patient has discomfort at
the wrist. Stimulating electrodes are 10mm gold disk, stimulus intensity
is 20 mA, and stimulus duration is 100 microseconds. Which of the
following would most likely reduce the patients discomfort while
maintaining adequate stimulation? Answer: Decrease the stimulus
intensity to motor threshold
◉ To4 is used to determine which of the following values? Answer:
level of neuromuscular blockage present
◉ Which of the following is a common complication of microvascular
decompression of cranial nerve VIII? Answer: Hearing loss
, ◉ Ischemic injury of the anterior spinal artery will affect which
modality first? Answer: tcMEPs
◉ Extreme cerebellar retraction during CPA tumor surgery likely results
in: Answer: Loss of all waves due to vascular compromise
◉ Wave I of the Brainstem Auditory Evoked Potential (BAEP) has a
typical post-stimulus latency of Answer: 2 ms
◉ According to ACNS Guidelines, what is the recommended placement
of the ground for a cervical procedure? Answer: Forearm
◉ If the brachial plexus is at risk for compression due to patient
positioning, the technologist, surgeon and neurophysiologist should
discuss adding which SSEP modality to the surgical plan? Answer:
Ulnar Nerve
◉ Which of the following is most likely an anesthetic change seen in
spine cases? Answer: Changes in cortical responses in bilateral UE and
LE SSEPs
◉ Which BAER click polarity eliminates the cochlear microphonic?
Answer: Alternating
