ASET CNIM TIPS SET ANSWERS AND QUESTIONS
SET A+
✔✔The effects of halogenated agents on the cortical SSEP are
1. increase in latencies and an increase in amplitudes
2. minimal compared with effects on BAERs
3. negligible
4. increase in latencies and decrease in amplitudes - ✔✔increase in latencies and a
decrease in amplitudes
✔✔A major disadvantage of monitoring only posterior tibial nerve SSEP during scoliosis
surer is the inability to
1. measure the effects of distraction on the spinal cord
2. measure the effects of translation of the spinal cord
3. detect ischemic injury to the anterior spinal cord
4. monitor highly variable responses to physiological factors such as heart rate and
blood pressure - ✔✔detect ischemic injury to the anterior spinal cord
✔✔One effect of ketamine on the SSEP is to
1. decrease amplitudes
2. increase amplitudes
3. decrease latencies
4. increased latencies - ✔✔increase amplitudes
✔✔Maximum variability of cortical EP potentials will most likely occur
1. during changes in anesthesia
2. after opening the surgical site
3. during electrocautery use
4. prior to lumbar laminectomy - ✔✔during changes in anesthesia
,✔✔The monitoring modality most likely to be affected by a large bolus of muscle
relaxant is the
1. cortical SSEP
2. BAER
3. myogenic evoked potential
4. NMEP - ✔✔myogenic evoked potential
✔✔Effect of volatile anesthetic agents on cortical EPs is to
1. decrease latencies
2. prolong latencies and decrease amplitudes
3. increase amplitudes
4. decrease amplitudes and decrease latencies - ✔✔prolong latencies and decrease
amplitudes
✔✔Drop in temp of the patients legs can cause
1. decrease in amplitude of SSEP waveforms
2. increase in amplitude of L3S response
3. a prolongation of SSEP peak latencies
4. increase in the conduction velocity of the tibial nerve - ✔✔a prolongation of SSEP
peak latencies
✔✔During a posterior fossa approach for removal of an acoustic neuroma, an increase
in the latency of wave V is most likely caused by
1. fluid in ear canal
2. retraction of the cerebellum
3. failure to stimulate
4. loss of blood supply to the cochlea - ✔✔retraction of the cerebellum
✔✔the ISOLA type of spinal instrumentation usually involves
1. placement of grid electrodes
2. supralaminar placement of of rods
3. severing the cauda equina
4. a combination hook and screw method - ✔✔a combination hook and screw method
✔✔EP monitoring team must
1. include a medical engineer
2. communicate on a regular basis and work in shifts throughout surgical procedures
3. communicate any changes in the study and be able to solve technical difficulties
, 4. include anesthesiologist - ✔✔communicate any changes in the study and be able to
solve technical difficulties
✔✔Early changes to CMAPs during exposure of CN VII are most likely due to
1. increase in inhalation agents
2. severe blood loss
3. changes in patients state of consciousness
4. heating from the electrical cautery device - ✔✔heating from the electrical cautery
device
✔✔SSEP during scoliosis surgery may replace a need for the
1. O'Hara clonus test
2. Stagnara wake up test
3. Ruben hematocrit test
4 neurologic exam - ✔✔Stagnara wake up test
✔✔SSEPs are most likely to be highly variable and less reliable in patients with
1. MS
2. history of nicotine abuse
3. tethered spinal cord
4. neuromuscular disease - ✔✔neuromuscular disease
✔✔Luque rods would best be used
1. treat vascular compression of CN V
2. repair acetabular fracture
3. for posterior spinal fixation
4. anterior cervical fusion stabilzation - ✔✔for posterior spinal fixation
✔✔A "false-negative" test
1. is the desired goal of IONM
2. means that the test results do not show an abnormality when a clinical abnormality is
present
3. means that the test results show an abnormality when no clinical abnormality exists
4. presents the N18 wave as a positive down-going response - ✔✔means that the test
results do not show an abnormality when a clinical abnormality is present
✔✔During scoliosis surgery, the spinal cord is most at risk for injury
1. after the initial incision and at closing
2. during hypotension induced by anesthesiologist
SET A+
✔✔The effects of halogenated agents on the cortical SSEP are
1. increase in latencies and an increase in amplitudes
2. minimal compared with effects on BAERs
3. negligible
4. increase in latencies and decrease in amplitudes - ✔✔increase in latencies and a
decrease in amplitudes
✔✔A major disadvantage of monitoring only posterior tibial nerve SSEP during scoliosis
surer is the inability to
1. measure the effects of distraction on the spinal cord
2. measure the effects of translation of the spinal cord
3. detect ischemic injury to the anterior spinal cord
4. monitor highly variable responses to physiological factors such as heart rate and
blood pressure - ✔✔detect ischemic injury to the anterior spinal cord
✔✔One effect of ketamine on the SSEP is to
1. decrease amplitudes
2. increase amplitudes
3. decrease latencies
4. increased latencies - ✔✔increase amplitudes
✔✔Maximum variability of cortical EP potentials will most likely occur
1. during changes in anesthesia
2. after opening the surgical site
3. during electrocautery use
4. prior to lumbar laminectomy - ✔✔during changes in anesthesia
,✔✔The monitoring modality most likely to be affected by a large bolus of muscle
relaxant is the
1. cortical SSEP
2. BAER
3. myogenic evoked potential
4. NMEP - ✔✔myogenic evoked potential
✔✔Effect of volatile anesthetic agents on cortical EPs is to
1. decrease latencies
2. prolong latencies and decrease amplitudes
3. increase amplitudes
4. decrease amplitudes and decrease latencies - ✔✔prolong latencies and decrease
amplitudes
✔✔Drop in temp of the patients legs can cause
1. decrease in amplitude of SSEP waveforms
2. increase in amplitude of L3S response
3. a prolongation of SSEP peak latencies
4. increase in the conduction velocity of the tibial nerve - ✔✔a prolongation of SSEP
peak latencies
✔✔During a posterior fossa approach for removal of an acoustic neuroma, an increase
in the latency of wave V is most likely caused by
1. fluid in ear canal
2. retraction of the cerebellum
3. failure to stimulate
4. loss of blood supply to the cochlea - ✔✔retraction of the cerebellum
✔✔the ISOLA type of spinal instrumentation usually involves
1. placement of grid electrodes
2. supralaminar placement of of rods
3. severing the cauda equina
4. a combination hook and screw method - ✔✔a combination hook and screw method
✔✔EP monitoring team must
1. include a medical engineer
2. communicate on a regular basis and work in shifts throughout surgical procedures
3. communicate any changes in the study and be able to solve technical difficulties
, 4. include anesthesiologist - ✔✔communicate any changes in the study and be able to
solve technical difficulties
✔✔Early changes to CMAPs during exposure of CN VII are most likely due to
1. increase in inhalation agents
2. severe blood loss
3. changes in patients state of consciousness
4. heating from the electrical cautery device - ✔✔heating from the electrical cautery
device
✔✔SSEP during scoliosis surgery may replace a need for the
1. O'Hara clonus test
2. Stagnara wake up test
3. Ruben hematocrit test
4 neurologic exam - ✔✔Stagnara wake up test
✔✔SSEPs are most likely to be highly variable and less reliable in patients with
1. MS
2. history of nicotine abuse
3. tethered spinal cord
4. neuromuscular disease - ✔✔neuromuscular disease
✔✔Luque rods would best be used
1. treat vascular compression of CN V
2. repair acetabular fracture
3. for posterior spinal fixation
4. anterior cervical fusion stabilzation - ✔✔for posterior spinal fixation
✔✔A "false-negative" test
1. is the desired goal of IONM
2. means that the test results do not show an abnormality when a clinical abnormality is
present
3. means that the test results show an abnormality when no clinical abnormality exists
4. presents the N18 wave as a positive down-going response - ✔✔means that the test
results do not show an abnormality when a clinical abnormality is present
✔✔During scoliosis surgery, the spinal cord is most at risk for injury
1. after the initial incision and at closing
2. during hypotension induced by anesthesiologist
