CNIM Practice Exam Questions – Certified
Neurophysiologic Intraoperative Monitoring
Exam Practice
When monitoring EMG, which of the following would most likely indicate nerve damage post op?
A) CMAP to direct nerve stim
B) Occasional muscle fasciculations
C) Continuous trains of discharge
D) Occasional bursts of discharge - ANSWER ✔ C) Continuous trains of discharge
If a surgeon is using the popular Transsphenoidal approach to a pituitary tumor, in which he/she may
likely request VEP monitoring, the surgeon would need to make a hole in which part of the cranium in
order to access the tumor?
A) IAC
B) foramen ovale
C) Sphenoid sinus
D) maxillary - ANSWER ✔ C) Sphenoid sinus
A bolus of narcotics (like Fentanyl) right before TcMEPs are run will cause:
A) Increase in MEP amplitudes
B) No change in MEP amplitudes
C) MEPs will increase or decrease all depending on the dosage
D) MEP amplitudes will decrease - ANSWER ✔ D) MEP amplitudes will decrease
- This should be a very small change as narcotics do not affect the modality much. However it will still
affect the amplitudes somewhat.
In selecting the horizontal parameters of analysis:
A) The analysis period should be at least twice the highest frequency in the signal.
B) The sampling rate should be at least twice the highest frequency in the signal.
C) The dwell time should be at least twice the highest frequency in the signal.
, CNIM Practice Exam Questions – Certified
Neurophysiologic Intraoperative Monitoring
Exam Practice
D) The sampling rate should equal the highest frequency in the signal. - ANSWER ✔ B) The sampling rate
should be at least twice the highest frequency in the signal.
- In selecting the horizontal parameters, the sampling rate must be twice the highest frequency in the
signal, in order to avoid aliasing. This is the Nyquist theorem. If the sampling rate is too slow, the
digitized signal will appear as a slower frequency than the analog signal of interest.
A positive Babinski sign is apparent when the toes _________ upon stroking the sole of the foot with an
instrument. This would depict a(n)______.
A) curl/ upper motor neuron lesion
B) curl/lower motor neuron lesion
C) fan/upper motor neuron lesion
D) fan/lower motor neuron lesion - ANSWER ✔ C) fan/upper motor neuron lesion
It's important to have matched impedances because:
A) it optimizes your horizontal resolution
B) it maximizes the CMRR
C) it minimizes the CMRR
D) it is safer for the patient - ANSWER ✔ B) it maximizes the CMRR
- Feedback:
Matched electrode impedances will maximize the Common Mode Rejection Ratio which in turn will
optimize the VERTICAL resolution. If you have mis-matched impedances then one electrode will record
more noise than the other; this is NOT favorable for Common Mode Rejection to work properly. We
want the Common Mode Rejection Ratio to be as high as possible so the noise and artifact that are
common to both channels/inputs gets cancelled out.
Minimum required vertical resolution
Neurophysiologic Intraoperative Monitoring
Exam Practice
When monitoring EMG, which of the following would most likely indicate nerve damage post op?
A) CMAP to direct nerve stim
B) Occasional muscle fasciculations
C) Continuous trains of discharge
D) Occasional bursts of discharge - ANSWER ✔ C) Continuous trains of discharge
If a surgeon is using the popular Transsphenoidal approach to a pituitary tumor, in which he/she may
likely request VEP monitoring, the surgeon would need to make a hole in which part of the cranium in
order to access the tumor?
A) IAC
B) foramen ovale
C) Sphenoid sinus
D) maxillary - ANSWER ✔ C) Sphenoid sinus
A bolus of narcotics (like Fentanyl) right before TcMEPs are run will cause:
A) Increase in MEP amplitudes
B) No change in MEP amplitudes
C) MEPs will increase or decrease all depending on the dosage
D) MEP amplitudes will decrease - ANSWER ✔ D) MEP amplitudes will decrease
- This should be a very small change as narcotics do not affect the modality much. However it will still
affect the amplitudes somewhat.
In selecting the horizontal parameters of analysis:
A) The analysis period should be at least twice the highest frequency in the signal.
B) The sampling rate should be at least twice the highest frequency in the signal.
C) The dwell time should be at least twice the highest frequency in the signal.
, CNIM Practice Exam Questions – Certified
Neurophysiologic Intraoperative Monitoring
Exam Practice
D) The sampling rate should equal the highest frequency in the signal. - ANSWER ✔ B) The sampling rate
should be at least twice the highest frequency in the signal.
- In selecting the horizontal parameters, the sampling rate must be twice the highest frequency in the
signal, in order to avoid aliasing. This is the Nyquist theorem. If the sampling rate is too slow, the
digitized signal will appear as a slower frequency than the analog signal of interest.
A positive Babinski sign is apparent when the toes _________ upon stroking the sole of the foot with an
instrument. This would depict a(n)______.
A) curl/ upper motor neuron lesion
B) curl/lower motor neuron lesion
C) fan/upper motor neuron lesion
D) fan/lower motor neuron lesion - ANSWER ✔ C) fan/upper motor neuron lesion
It's important to have matched impedances because:
A) it optimizes your horizontal resolution
B) it maximizes the CMRR
C) it minimizes the CMRR
D) it is safer for the patient - ANSWER ✔ B) it maximizes the CMRR
- Feedback:
Matched electrode impedances will maximize the Common Mode Rejection Ratio which in turn will
optimize the VERTICAL resolution. If you have mis-matched impedances then one electrode will record
more noise than the other; this is NOT favorable for Common Mode Rejection to work properly. We
want the Common Mode Rejection Ratio to be as high as possible so the noise and artifact that are
common to both channels/inputs gets cancelled out.
Minimum required vertical resolution
