During a scoliosis surgery, you recognize a gradual latency increase of 3.5 msec in the PTN cortical response, the subcortical response appears to be shifted out almost as much. All response amplitudes are unchanged. What is the appropriate action to take? a. Ignore the change, it means nothing. b....
During a scoliosis surgery, you recognize a gradual latency increase of 3.5 msec in the PTN cortical
response, the subcortical response appears to be shifted out almost as much. All response amplitudes
are unchanged. What is the appropriate action to take? a. Ignore the change, it means nothing. b. Inform
the surgeon immediately that changes consistent with spinal cord injury may have occurred.
Recommend a wake up test. c. Check the latencies of the PF and MN responses to see if they are also
shifted, indicating a possible temperature effect. Verify this by checking the patient's body temperature.
d. Ask the anesthetist to reduce the gases. You are seeing changes consistent with increased depth of
anesthesia. - ANSWER: ✔✔B
Which would not be considered contamination of the sterile field: a. Reaching your arm over the sterile
table b. Brushing your bouffant cap against the microscope drape c. Reaching underneath the surgeon's
gown to grab his pager d. Dropping a junior mint into the wound - ANSWER: ✔✔C
The Auditory Evoked Potential (ABR) typically involves what type of stimulus? a. Tone burst b. Electrical
pulse c. Click sound d. White noise - ANSWER: ✔✔C
Which of the following will result in significantly elevated SSEP latencies? a. Positive patellar reflex b.
Brown-Sequard syndrome c. Charcot-Marie Tooth disease d. Carotid stenosis - ANSWER: ✔✔C
The Vertical Resolution of an evoked potential system depends primarily on: a. The analysis period b. The
sampling Rate c. The filter settings d. The number of bits in the A/D Converter - ANSWER: ✔✔D
During a thoracic laminectomy, a rapid loss of the right PTN cortical responses occurs. The cervical
response is too poor to evaluate, and the popliteal fossa responses are unchanged. What should you do
first? a. Run MN and check anesthetic levels. b. Inform the surgeon immediately and indicate that the
changes are consistent with a right hemi-cord injury. c. Check the right stimulator output with a bar
electrode. d. Reset the amplifier, check your recording parameters, and wait to see if the responses
return - ANSWER: ✔✔B
,The most frequent source of patient infection in the operating room derives from: a. The patient's own
endogenous flora b. Non-sterile instruments c. Bacteria from the surgical staff d. Bacteria from the
operating room environment - ANSWER: ✔✔A
During a posterior fossa resection of acoustic neuroma surgery, you observe the loss of wave II of the
BAER. What should you do? a. Inform the surgeon. This indicates significant damage to the VIIIth nerve
b. Check the contralateral BAER to confirm a lesion in the pons c. Continue to monitor without alarm d.
Check anesthetic levels - ANSWER: ✔✔C
What is the most appropriate first step in troubleshooting responses from a cortical grid that show
nothing but artifact in the recording? a. Reboot the machine b. Make sure the grid is in good contact
with the brain and is correct side down c. Get a new electrode. They often are poor quality d. Make sure
the stimulators are connected properly - ANSWER: ✔✔B
One of the risks of a wake up test is a. Decreased blood pressure b. Accidental extubation c. Cardiac
problems d. Muscle fatigue - ANSWER: ✔✔C
What will most likely affect SSEPs a. Spinal cord tumor b. Degenerative motor condition c. Anterior spinal
hypoperfusion d. Scoliosis - ANSWER: ✔✔A
The main source of airborne bacteria in the operating room is from: a. Plume resulting from
electrocautery b. Operating room personnel talking, laughing and coughing c. Exfoliated skin particles
from the operating room staff d. Flies in the operating room - ANSWER: ✔✔C
Excessive cerumen may cause: a. Absence of the BAER b. Increased I - V interpeak c. Increased I - III
interpeak d. Absence of wave V - ANSWER: ✔✔A
After-discharges occur after what? a. Seizure b. Transcranial motor stimulation c. Direct cortical
stimulation d. Phase reversal - ANSWER: ✔✔C
A 10-bit A/D Converter has how many discrete voltage values in its range? a. 256 b. 512 c. 1024 d. 2048 -
ANSWER: ✔✔C
,During an anterior lumbar fusion (L4-L5), a loss of all right PTN responses occurs over the course of
about five minutes. What should you do? a. Inform the surgeon the right stimulator has failed, but that
you will continue to diligently monitor the left side. b. Check the current output and stimulator
connections quickly. Then inform the surgeon you are seeing changes consistent with ischemia of the
right leg. c. Inform the surgeon there may be spinal cord changes. d. Check MN responses for possible
anesthetic changes. - ANSWER: ✔✔B
Which of the following drugs significantly affect the Transcranial Motor D-wave amplitude? a. Isoflurane
b. Pavulon c. Propofol d. None of the above - ANSWER: ✔✔A
Lack of after-discharges indicates: a. Stimulation is not over a functional motor or language area b. The
stimulus is adequate to activate motor or language areas c. The stimulus is inadequate to activate motor
or language areas d. The stimulus is likely below the threshold of seizure activation - ANSWER: ✔✔D
What is the minimum required vertical resolution of an evoked potential system? a. 8 bits b. 16 bits c. 80
bits d. 256 bits - ANSWER: ✔✔A
Compound muscle action potentials to transcranial electric stimulation are susceptible to: a. Isoflurane
b. Pavulon c. Propofol d. All of the above - ANSWER: ✔✔A
Which of the following is most consistent with a discrete lesion of the medial geniculate body: a. Loss of
wave V b. Loss of waves III - V c. Loss of waves II - V d. No change in waves I - V - ANSWER: ✔✔D
When no phase reversal is present in an anterior-posterior cortical grid recording: a. The grid is over the
Pre-central gyrus b. The maximum amplitude response is closest to the central sulcus c. The grid is over
the post-central gyrus d. The grid should be turned 90 degrees in order to find the phase reversal -
ANSWER: ✔✔B
A match must be made between the size of the recorded signal and the range of the A/D Converter: a. To
prevent aliasing of the signal b. To accurately represent the amplitude of the signal c. To prevent
unnecessary artifact rejection d. To accurately measure the latency of a peak - ANSWER: ✔✔B
Train stimuli are used for TCMEP's in order to a. Charge the patient more b. Overcome anesthetic
suppression of synaptic transmissions in the motor pathway c. Activate D-waves in the peripheral
muscles d. Negate the effects of neuromuscular blockade - ANSWER: ✔✔B
, The Facial nerve CMAP response has a latency of approximately: a. 3 msec b. 5 msec c. 7 msec d. 10
msec - ANSWER: ✔✔C
Cotrel-Dubousset instrumentation involves which of the following? a. Sublaminar wires b. Derotation c.
Distraction d. Intervertebral diskectomy - ANSWER: ✔✔B
The D-wave is recorded from the: a. Peripheral nerve b. Peripheral limb muscle c. Spinal cord d. Cerebral
cortex - ANSWER: ✔✔B
The primary risk to the spinal cord during Luque instrumentation is: a. Placement of bone graft b.
Insertion of pedicle screws c. Placement of wires d. Derotation of the rod - ANSWER: ✔✔C
If the bin width of your system is 20 μS, then the highest frequency signal that can be resolved is: a. 50
KHz b. 25 KHz c. 20 KHz d. 100 KHz - ANSWER: ✔✔A
When testing SSEP from the upper extremity, an electrode placed at Erb's point will record activity
generated from: a. brachial plexus b. lumbar plexus c. cauda equine d. thalamocortical radiations -
ANSWER: ✔✔A
Which of the following is NOT a safety concern regarding the use of TCMEPs? a. Patient's history of
seizure disorder b. Patient has a pacemaker c. Patient history of cerebral palsy d. Activation of biting
muscles during stimulation - ANSWER: ✔✔C
Random spike discharges can be heard from a speaker during facial nerve dissection in all of the
following except: a. Irrigation b. Heating effects c. Traction on the nerve d. During electrocautery e.
Drying of the nerve - ANSWER: ✔✔D
Harrington rod instrumentation uses: a. Hooks and a rod b. Rods and screws c. Wires and rods d. Rods,
hooks, and screws - ANSWER: ✔✔A
What EEG changes would you expect after intra-carotid sodium amytal? a. Diffuse decrease b. Ictal
discharges c. Contralateral decrease in high frequency d. Ipsilateral decrease in high frequency -
ANSWER: ✔✔D
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