CNIM FINAL EXAM AND PRACTICE EXAM LATEST ACTUAL
EXAM
Platinum electrodes are ideal under what circumstances?
A)when high voltage stimulation is applied
B)when stimulating through the cranium
C)in guarding against neurotoxicity for direct stimulation or recording
D)in guarding against artifact for cortical recordings - ANSWER: C)in guarding against
neurotoxicity for direct stimulation or recording
To eliminate crossover, ACNS guidelines suggest masking noise be set to ____.
A)60 db HL
B)60 dB SPL
C)75 dB HL
D)75 dB nHL - ANSWER: B)60 dB SPL
Or 30-35dBHL would have also being the correct answer.
When stimulating TES-MEPs from C3-C4, responses are mostly present on the
patient's right sided muscles. Where is the cathode?
A)C3
B)C4
C)C2
D)Cz - ANSWER: B)C4
TcMEP (TES-MEP) uses anodal stimulation, so anode at C3 (Left) = MEPs MOSTLY on
the RIGHT side of the body. Cathode would be on the opposite side at C4.
D waves:
A)Stimulated epidurally
B)More sensitive to ischemia than TcMEPs
C)Unaffected by muscle relaxant
D)Differentiate between Left and Right corticospinal tracts - ANSWER: C)Unaffected
by muscle relaxant
D waves are "direct" waves elicited by stimulation of the pyramidal neurons in the
corticospinal pathway. Conversely, I waves are "indirect" waves elicited by
stimulation of interneurons in the cortex which then synapse with pyramidal
neurons and result in depolarization of the corticospinal pathway in the spinal cord.
D and I waves are recorded over the epidural space of the spinal cord and are
,therefore unaffected by muscle relaxant and cannot clearly distinguish left and right.
D waves are also less sensitive to ischemia than muscle MEPs.
What modalities should you run for a MVD (Microvascular Decompression)?
A)BAER and CN EMG
B)SSEP and EEG
C)MEP and EEG
D)SSEP and MEP - ANSWER: A)BAER and CN EMG
These surgeries are performed to alleviate pressure on a cranial nerve from an
offending vessel. You should perform EMG from that cranial nerve. You also need to
monitor the brainstem so BAERs are great for that.
Which of the following techniques would be the most useful in IONM of a Left ACA
aneurysm?
A)L MN Cortical SSEPs
B)R MN Cortical SSEPs
C)L PTN Cortical SSEPs
D)R PTN Cortical SSEPs - ANSWER: D)R PTN Cortical SSEPs
Don't be fooled on the pathway though and remember where the axons land in the
longitudinal fissure on the OPPOSITE side of stimulation. The are just best recorded
ipsilateral to the side of stim.
Which nerve innervates the Abductor Pollicis Brevis Muscle?
A)Radial
B)Median
C)Ulnar
D)Sural - ANSWER: B)Median
Which derivation is optimal for isolating brainstem potentials following median
nerve stimulation?
A)CS5 - FPZ
B)CPi - EPc
C)CS5 - EPc
D)CPc - EPi - ANSWER: B)CPi - EPc
To isolate cortical it would be CPc-CPi
With a signal to noise ratio of 1:2, averaging 64 responses will:
A)Reduce the noise by 50%
B)Not change the ratio
,C)Improve the ratio to 8:1
D)Improve the ratio to 4:1 - ANSWER: D)Improve the ratio to 4:1
Signal to Noise Ratio out = SNRin ∙ √N
SNRin is 1:2.
N is the number of averages (here it is 64).
We are solving for SNRout.
SSEP acquisition is obliterated by the use of:
A)midas rex drilling
B)Instrument artifact when surgeon hammers in implants
C)monopolar cautery
D)the use of C-Arm - ANSWER: C)monopolar cautery
Which anesthetic agent will have the largest effect on the TES D-wave amplitude (D-
wave is recorded from the spinal cord)
A)Sevoflurane
B)Propofol
C)Rocuronium
D)None - ANSWER: D)None
D-waves are not effected by anesthesia. They are recorded right over the spinal cord
as the propagated volley travels efferently down the spinal cord. To get to this point
in the pathway there are NO synapses, so no need for Temporal summation, TIVA, or
the need to cross the NMJ.
___________ is the sampling rate that must be used to avoid aliasing. It is twice the
fastest frequency of the sine wave.
A)Spectral Edge
B)CMRR
C)Nyquist frequency
D)Bin width - ANSWER: C)Nyquist frequency
The brain is made of:
A)Stem cells and glial cells
B)Neurons and glial cells
C)Neurons and blastocysts
D)Neurons and Schwann cells - ANSWER: B)Neurons and glial cells
The brain is made up of neurons and glial cells. Glial cells, also called neuroglia,
provide support and protection for neurons in the CNS and PNS. In the CNS, glial cells
include oligodendrocytes, astrocytes, ependymal cells, and microglia. In the PNS,
glial cells include Schwann cells and satellite cells.
, What modalities should you run on a Chiari Malformation?
A)SSEP, TcMEP, EEG
B)SSEP, TcMEP, EMG
C)SSEP, TcMEP, BAER
D)SSEP, EEG, EMG - ANSWER: C)SSEP, TcMEP, BAER
Chiari Malformations put the very top of the spinal cord and lower
brainstem/cerebellum at risk. Because of this, the best modalities would be SSEP,
TcMEP (as they pass through this pathway) and also BAERs which monitor the
brainstem. EMG doesn't serve much purpose on these cases as you are higher than
exiting cervical nerve roots.
If a patient's stimulus threshold is 20dB SPL, what is the intensity of stimulus when
the patient is tested at 80dB SPL?
A)60 dB nHL
B)60 dB SL
C)0 dB HL
D)20 dB HL - ANSWER: B)60 dB SL
If the patient's hearing threshold is 20 dB SPL, that means that 20 dB is actually 0 dB
Sensation Level (SL) for that individual. If you increase the intensity to 80 dB that is
60 dB SL for that individual patient. It would also be 80 dB SPL. So either 60 dB SL or
80 dB SPL would be correct. Only one is given of course.
Current
A)The potential for electrons to move between two poles
B)The amount of energy that is stored
C)The measurement of the impedance
D)The flow of electrons between two poles - ANSWER: D)The flow of electrons
between two poles
Trigeminal nerve neuralgia is usually caused by compression by which artery?
A)AICA
B)SCA
C)PCA
D)MCA - ANSWER: B)SCA
The Superior Cerebellar Artery is usually the offending artery that compresses and
pulsates against the trigeminal nerve.
NMEPs are:
EXAM
Platinum electrodes are ideal under what circumstances?
A)when high voltage stimulation is applied
B)when stimulating through the cranium
C)in guarding against neurotoxicity for direct stimulation or recording
D)in guarding against artifact for cortical recordings - ANSWER: C)in guarding against
neurotoxicity for direct stimulation or recording
To eliminate crossover, ACNS guidelines suggest masking noise be set to ____.
A)60 db HL
B)60 dB SPL
C)75 dB HL
D)75 dB nHL - ANSWER: B)60 dB SPL
Or 30-35dBHL would have also being the correct answer.
When stimulating TES-MEPs from C3-C4, responses are mostly present on the
patient's right sided muscles. Where is the cathode?
A)C3
B)C4
C)C2
D)Cz - ANSWER: B)C4
TcMEP (TES-MEP) uses anodal stimulation, so anode at C3 (Left) = MEPs MOSTLY on
the RIGHT side of the body. Cathode would be on the opposite side at C4.
D waves:
A)Stimulated epidurally
B)More sensitive to ischemia than TcMEPs
C)Unaffected by muscle relaxant
D)Differentiate between Left and Right corticospinal tracts - ANSWER: C)Unaffected
by muscle relaxant
D waves are "direct" waves elicited by stimulation of the pyramidal neurons in the
corticospinal pathway. Conversely, I waves are "indirect" waves elicited by
stimulation of interneurons in the cortex which then synapse with pyramidal
neurons and result in depolarization of the corticospinal pathway in the spinal cord.
D and I waves are recorded over the epidural space of the spinal cord and are
,therefore unaffected by muscle relaxant and cannot clearly distinguish left and right.
D waves are also less sensitive to ischemia than muscle MEPs.
What modalities should you run for a MVD (Microvascular Decompression)?
A)BAER and CN EMG
B)SSEP and EEG
C)MEP and EEG
D)SSEP and MEP - ANSWER: A)BAER and CN EMG
These surgeries are performed to alleviate pressure on a cranial nerve from an
offending vessel. You should perform EMG from that cranial nerve. You also need to
monitor the brainstem so BAERs are great for that.
Which of the following techniques would be the most useful in IONM of a Left ACA
aneurysm?
A)L MN Cortical SSEPs
B)R MN Cortical SSEPs
C)L PTN Cortical SSEPs
D)R PTN Cortical SSEPs - ANSWER: D)R PTN Cortical SSEPs
Don't be fooled on the pathway though and remember where the axons land in the
longitudinal fissure on the OPPOSITE side of stimulation. The are just best recorded
ipsilateral to the side of stim.
Which nerve innervates the Abductor Pollicis Brevis Muscle?
A)Radial
B)Median
C)Ulnar
D)Sural - ANSWER: B)Median
Which derivation is optimal for isolating brainstem potentials following median
nerve stimulation?
A)CS5 - FPZ
B)CPi - EPc
C)CS5 - EPc
D)CPc - EPi - ANSWER: B)CPi - EPc
To isolate cortical it would be CPc-CPi
With a signal to noise ratio of 1:2, averaging 64 responses will:
A)Reduce the noise by 50%
B)Not change the ratio
,C)Improve the ratio to 8:1
D)Improve the ratio to 4:1 - ANSWER: D)Improve the ratio to 4:1
Signal to Noise Ratio out = SNRin ∙ √N
SNRin is 1:2.
N is the number of averages (here it is 64).
We are solving for SNRout.
SSEP acquisition is obliterated by the use of:
A)midas rex drilling
B)Instrument artifact when surgeon hammers in implants
C)monopolar cautery
D)the use of C-Arm - ANSWER: C)monopolar cautery
Which anesthetic agent will have the largest effect on the TES D-wave amplitude (D-
wave is recorded from the spinal cord)
A)Sevoflurane
B)Propofol
C)Rocuronium
D)None - ANSWER: D)None
D-waves are not effected by anesthesia. They are recorded right over the spinal cord
as the propagated volley travels efferently down the spinal cord. To get to this point
in the pathway there are NO synapses, so no need for Temporal summation, TIVA, or
the need to cross the NMJ.
___________ is the sampling rate that must be used to avoid aliasing. It is twice the
fastest frequency of the sine wave.
A)Spectral Edge
B)CMRR
C)Nyquist frequency
D)Bin width - ANSWER: C)Nyquist frequency
The brain is made of:
A)Stem cells and glial cells
B)Neurons and glial cells
C)Neurons and blastocysts
D)Neurons and Schwann cells - ANSWER: B)Neurons and glial cells
The brain is made up of neurons and glial cells. Glial cells, also called neuroglia,
provide support and protection for neurons in the CNS and PNS. In the CNS, glial cells
include oligodendrocytes, astrocytes, ependymal cells, and microglia. In the PNS,
glial cells include Schwann cells and satellite cells.
, What modalities should you run on a Chiari Malformation?
A)SSEP, TcMEP, EEG
B)SSEP, TcMEP, EMG
C)SSEP, TcMEP, BAER
D)SSEP, EEG, EMG - ANSWER: C)SSEP, TcMEP, BAER
Chiari Malformations put the very top of the spinal cord and lower
brainstem/cerebellum at risk. Because of this, the best modalities would be SSEP,
TcMEP (as they pass through this pathway) and also BAERs which monitor the
brainstem. EMG doesn't serve much purpose on these cases as you are higher than
exiting cervical nerve roots.
If a patient's stimulus threshold is 20dB SPL, what is the intensity of stimulus when
the patient is tested at 80dB SPL?
A)60 dB nHL
B)60 dB SL
C)0 dB HL
D)20 dB HL - ANSWER: B)60 dB SL
If the patient's hearing threshold is 20 dB SPL, that means that 20 dB is actually 0 dB
Sensation Level (SL) for that individual. If you increase the intensity to 80 dB that is
60 dB SL for that individual patient. It would also be 80 dB SPL. So either 60 dB SL or
80 dB SPL would be correct. Only one is given of course.
Current
A)The potential for electrons to move between two poles
B)The amount of energy that is stored
C)The measurement of the impedance
D)The flow of electrons between two poles - ANSWER: D)The flow of electrons
between two poles
Trigeminal nerve neuralgia is usually caused by compression by which artery?
A)AICA
B)SCA
C)PCA
D)MCA - ANSWER: B)SCA
The Superior Cerebellar Artery is usually the offending artery that compresses and
pulsates against the trigeminal nerve.
NMEPs are:
