Grab bag
When monitoring intraoperative evoked potentials, which of the following is most likely to correlate with postoperative deficits?
A. No change in latency or amplitude
B. Latency decreases and amplitude increases
C. Transient changes of latency or amplitude
D. Persistent loss of wave forms
D. Persistent loss of wave forms
ANKYLOSIS
A. Foot drop
B. Wrist drop
C. Fused joint
D. Arterial occlusion
C. Fused joint
If a patient presents with ipsilateral cranial nerve symptoms and contralateral paralysis and paresthia, where is a lesion most likely located?
A. Spinal cord
B. Brainstem
C. Cerebellum
D. Cerebral hemisphere
B. Brainstem
During posterior fossa surgery wave V of the BAEP’s may increase in latency due to?
A. Spinal drainage
B. Retraction of the cerebellum
C. Warming of the nerve
D. Use of neuromuscular blocking agent
B. Retraction of the cerebellum
Fentanyl is a?
A. Narcotic agent
B. Volatile agent
C. Barbiturate agent
D. Neuromuscular blocking agent
A. Narcotic agent
Which of the following best describes a false negative case?
A. Evoked potentials disappear but reappear within 15 minutes
B. Evoked potentials have a greater than 50% decrease of amplitude with no neurological deficit
C. Evoked potentials remain relatively stable but postoperative neurologic deficits occur
D. Evoked potentials disappear during surgery and patient has no postoperative deficit
C. Evoked potentials remain relatively stable but postoperative neurologic deficits occur
The use of intraoperative monitoring during scoliosis surgery may replace the …
A. Hoffman sign
B. Stagnara test
C. Romberg test
D. Babinski sign
B. Stagnara test
Monitoring the posterior tibial nerve SSEPs is most appropriate in cerebrovascular procedures involving which of the following arteries?
A. Middle cerebral
B. Internal carotid
C. Anterior cerebral
D. Posterior cerebral
C. Anterior cerebral
Masking is recommended to eliminate?
A. Asymmetry in latency and amplitude
B. False negative from the ipsilateral ear
C. Bone-conducted responses from the non-stimulated ear
D. False positive from the ipsilateral ear
C. Bone-conducted responses from the non-stimulated ear
Which of the following is an effect of temperature on SSEPs?
A. Cooler temperatures tend to accelerate central conduction time
B. Warmer temperatures tend to polarize the stimulus current
C. Cooler temperatures tend to slow peripheral conduction time
D. Warmer temperatures desensitize nerve endings
C. Cooler temperatures tend to slow peripheral conduction time
If you have a lot of high frequency noise present in your signal, what can you do?
A. Increase HFF
B. Decrease HFF
C. Increase LFF
D. Decrease LFF
B. Decrease HFF
The effects of Harrington rod distraction on the spinal cord can be tested by all of the following except
A. The Stagnara wake-up test
B. Somatosensory EPs
C. Motor EPs
D. Dorsal root stimulation
D. Dorsal root stimulation
Which of the following cranial nerves innervates the lateral rectus muscle?
A. Optic
B. Facial
C. Abducens
D. Trigeminal
C. Abducens
Which of the following most often causes a temporary threshold shift on the Brainstem auditory evoked potentials during CPA?
A. Drilling
B. Bipolar Cautery
C. Warm Irrigation
D. CUSA
A. Drilling
In intraoperative monitoring of SSEPs, which of the following waves is LEAST affected by anesthetic agents?
A. P14
B. N20
C. N37
D. P37
A. P14
For patients showing clamp related EEG changes during carotid endarterectomy 80% if the changes appear within the
A. First 10 seconds
B. First 60 seconds
C. Frontal leads only
D. Alpha frequency range
B. First 60 seconds
In spinal surgery, the primary purpose of the popliteal fossa recording electrodes is to …
A. Verify adequacy of stimulus
B. Limit current spread
C. Confirm amplifier integrity
D. Provide evidence of a muscle twitch
A. Verify adequacy of stimulus
While stimulating cranial nerve VII a bipolar type stimulator has an advantage over a monopolar stimulator by
A. Requiring less current
B. Having greater specificity
C. Being less expensive
D. Presenting less risk of damage to the neural tissue
B. Having greater specificity
Which of the following is the down going potential recorded at about 12 msec following stimulation of the ear in the following diagram?
A. Wave VII
B. Postauricular muscle reflex
C. Long latency response
D. Middle latency response
B. Postauricular muscle reflex
The combination of nitrous oxide and volatile anesthetic gases affects SSEP’s by
A. Increasing latency and decreasing amplitude
B. Increasing latency and increasing amplitude
C. Decreasing latency and increasing amplitude
D. Decreasing latency and decreasing amplitude
A. Increasing latency and decreasing amplitude
In which of the following is the sampling rate of an averager at least twice the frequency of the fastest sine wave component in the signal to be resolved?
A. Ohm’s law
B. Wiener filtering
C. Nyquist frequency
D. Fourier analysis
C. Nyquist frequency
Which of the following nerve injuries usually does not produce spontaneous EMG activity during intraoperative monitoring
A. Heat
B. Pressure
C. Ischemia
D. Irrigation
C. Ischemia
Preservation of facial nerve CMAPs
A. Conclusively indicate preservation of function
B. Does not always indicate a good surgical outcome
C. Insures motor activity of the jaw
D. Indicates postoperative function of cranial nerve VIII
B. Does not always indicate a good surgical outcome
During posterior fossa surgery when BAERs are used for monitoring brainstem function, it is most important to?
A. Record cranial nerve VIII action potentials
B. Monitor cranial nerve V function ipsilaterally
C. Stimulate and record from the operative side only
D. Stimulate and record from the contralateral side
D. Stimulate and record from the contralateral side
If temperature is controlled, what effect will CNS depressants have on the interpeak latencies of the BAEP?
A. Prolongation of I-V
B. Prolongation of III-V
C. Decrease in interpeak latencies
D. No effect on interpeak latencies
D. No effect on interpeak latencies