CNIM EXAM 4 QUESTIONS AND 100% VERIFIED
ANSWERS
4. Based on an amplifier's 120dB common mode rejection ratio, which of the
following in-phase to out-of-phase signal ratios can be expected?
10,000:1
The answers are 100,000:1, 500,000:1, and 1,000,000:1.
7. Which of the following is opposed to any changes in current?
Capacitance
Impedance
Inductance
Resistance - ANSWER. Inductance
Inductance refers to an inductor's ability to retain energy in the form of a
magnetic field (and hence oppose current variations).
. Which of the following electrode materials exhibits minimal potential drift and
a high time constant?
Tin Gold Silver Stainless steel (answer: Gold)
Referential recording often reveals maximal amplitude cortical evoked
potentials after stimulation of the left posterior tibial nerve between: C3 and Cz,
C4 and P4, Fz and Cz, and C4 and Cz.
The contralateral medial cortex directs P37 to the ipsilateral scalp (CPz and
CPi).
Which of the following best captures the P37 peak after left posterior tibial
nerve stimulation?
CP3, CP4, Fpz, and C5S - ANSWER CP3.
The contralateral medial cortex directs P37 to the ipsilateral scalp (CPz and
CPi).
, Identifying wave V of the BAEP may need tympanic electrodes.
Bilateral stimulation.
Reducing stimulus intensity.
Use of a noncephalic reference. - ANSWER Reduced stimulus intensity. The
identification of wave V may necessitate a reduction in stimulus intensity.
Decreased intensity causes an increase in delay, making it easier to distinguish
from wave IV.
What is the most likely effect of isoflurane at MAC 1.5 on tibialis anterior
CMAP amplitude during spinal stimulation?
Significant increase
Significant reduction
Minimal reduction.
Minimum increase - ANSWER A significant drop occurs because the stimulus
is on the spinal cord above the alpha motor neuron, indicating that a synapse
must still occur. Anesthesia has a strong effect on synapses. Stimulation of a
peripheral neuron would have little effect because there is no synapse.
Which of the following is a critical surgical event?
Drilling the burr hole in the skull
Decorticating vertebral elements
Placing a muscle plug in the internal auditory canal
ANSWER: Resecting tumor pieces during acoustic neuroma excision.
Resecting tumor fragments during acoustic neuroma excision
Because it is near/on the brainstem, where motor sensory and cranial nerves
originate.
During carotid endarterectomies, the Spectral Edge Frequency is often set
around 60-67%.
70‐77%
80‐87%
90‐97% - ANSWER 90-97%
SEF - Spectral Edge Frequency (also known as PSE):
The PSE, often set to 90-97%, indicates the frequency at which a specific
proportion (e.g., 90%) of the power in the EEG resides.
ANSWERS
4. Based on an amplifier's 120dB common mode rejection ratio, which of the
following in-phase to out-of-phase signal ratios can be expected?
10,000:1
The answers are 100,000:1, 500,000:1, and 1,000,000:1.
7. Which of the following is opposed to any changes in current?
Capacitance
Impedance
Inductance
Resistance - ANSWER. Inductance
Inductance refers to an inductor's ability to retain energy in the form of a
magnetic field (and hence oppose current variations).
. Which of the following electrode materials exhibits minimal potential drift and
a high time constant?
Tin Gold Silver Stainless steel (answer: Gold)
Referential recording often reveals maximal amplitude cortical evoked
potentials after stimulation of the left posterior tibial nerve between: C3 and Cz,
C4 and P4, Fz and Cz, and C4 and Cz.
The contralateral medial cortex directs P37 to the ipsilateral scalp (CPz and
CPi).
Which of the following best captures the P37 peak after left posterior tibial
nerve stimulation?
CP3, CP4, Fpz, and C5S - ANSWER CP3.
The contralateral medial cortex directs P37 to the ipsilateral scalp (CPz and
CPi).
, Identifying wave V of the BAEP may need tympanic electrodes.
Bilateral stimulation.
Reducing stimulus intensity.
Use of a noncephalic reference. - ANSWER Reduced stimulus intensity. The
identification of wave V may necessitate a reduction in stimulus intensity.
Decreased intensity causes an increase in delay, making it easier to distinguish
from wave IV.
What is the most likely effect of isoflurane at MAC 1.5 on tibialis anterior
CMAP amplitude during spinal stimulation?
Significant increase
Significant reduction
Minimal reduction.
Minimum increase - ANSWER A significant drop occurs because the stimulus
is on the spinal cord above the alpha motor neuron, indicating that a synapse
must still occur. Anesthesia has a strong effect on synapses. Stimulation of a
peripheral neuron would have little effect because there is no synapse.
Which of the following is a critical surgical event?
Drilling the burr hole in the skull
Decorticating vertebral elements
Placing a muscle plug in the internal auditory canal
ANSWER: Resecting tumor pieces during acoustic neuroma excision.
Resecting tumor fragments during acoustic neuroma excision
Because it is near/on the brainstem, where motor sensory and cranial nerves
originate.
During carotid endarterectomies, the Spectral Edge Frequency is often set
around 60-67%.
70‐77%
80‐87%
90‐97% - ANSWER 90-97%
SEF - Spectral Edge Frequency (also known as PSE):
The PSE, often set to 90-97%, indicates the frequency at which a specific
proportion (e.g., 90%) of the power in the EEG resides.
