1. How can hypoxia affect evoked potentials?
A. Prolongs latency and reduces amplitude
B. Shortens latency and increases amplitude
C. Causes no changes in signals
D. Only affects motor pathways
Answer: A
Rationale: Hypoxia decreases neural conduction, leading to prolonged
latency and reduced amplitude in evoked potentials.
2. What is the purpose of SSEPs in IONM?
A. Monitor peripheral nerve function
B. Assess sensory pathways from peripheral nerves to the brain
C. Evaluate motor pathways
D. Detect muscle activity
Answer: B
Rationale: SSEPs assess the functional integrity of sensory pathways,
typically from the peripheral nerves to the somatosensory cortex.
3. What does a significant reduction in MEP amplitude without
complete loss suggest?
,A. Minor technical artifact
B. Temporary neural compromise
C. Irreversible motor pathway injury
D. Loss of sensory pathways
Answer: B
Rationale: Partial reduction in amplitude may indicate transient neural
compromise, such as ischemia or mechanical pressure.
4. What type of stimulation is used in transcranial motor evoked
potentials?
A. Electrical
B. Magnetic
C. Thermal
D. Mechanical
Answer: A
Rationale: Electrical stimulation is commonly used in transcranial
MEPs to activate motor pathways.
5. What does a sudden loss of MEPs during surgery most likely
indicate?
A. Brain ischemia
B. Damage to motor pathways
C. Peripheral nerve injury
, D. Anesthetic effects
Answer: B
Rationale: Loss of MEPs often suggests a disruption in motor
pathways, which may result from ischemia, nerve injury, or spinal cord
compromise.
6. What can reduce artifact interference during IONM?
A. Using needle electrodes
B. Increasing ambient noise
C. Lowering signal gain
D. Adjusting patient temperature
Answer: A
Rationale: Needle electrodes are less susceptible to external noise and
reduce artifacts.
7. Which response indicates nerve irritation during free-running
EMG?
A. Loss of signal
B. Bursts of activity
C. Increased amplitude of SSEPs
D. Reduced signal latency
Answer: B
A. Prolongs latency and reduces amplitude
B. Shortens latency and increases amplitude
C. Causes no changes in signals
D. Only affects motor pathways
Answer: A
Rationale: Hypoxia decreases neural conduction, leading to prolonged
latency and reduced amplitude in evoked potentials.
2. What is the purpose of SSEPs in IONM?
A. Monitor peripheral nerve function
B. Assess sensory pathways from peripheral nerves to the brain
C. Evaluate motor pathways
D. Detect muscle activity
Answer: B
Rationale: SSEPs assess the functional integrity of sensory pathways,
typically from the peripheral nerves to the somatosensory cortex.
3. What does a significant reduction in MEP amplitude without
complete loss suggest?
,A. Minor technical artifact
B. Temporary neural compromise
C. Irreversible motor pathway injury
D. Loss of sensory pathways
Answer: B
Rationale: Partial reduction in amplitude may indicate transient neural
compromise, such as ischemia or mechanical pressure.
4. What type of stimulation is used in transcranial motor evoked
potentials?
A. Electrical
B. Magnetic
C. Thermal
D. Mechanical
Answer: A
Rationale: Electrical stimulation is commonly used in transcranial
MEPs to activate motor pathways.
5. What does a sudden loss of MEPs during surgery most likely
indicate?
A. Brain ischemia
B. Damage to motor pathways
C. Peripheral nerve injury
, D. Anesthetic effects
Answer: B
Rationale: Loss of MEPs often suggests a disruption in motor
pathways, which may result from ischemia, nerve injury, or spinal cord
compromise.
6. What can reduce artifact interference during IONM?
A. Using needle electrodes
B. Increasing ambient noise
C. Lowering signal gain
D. Adjusting patient temperature
Answer: A
Rationale: Needle electrodes are less susceptible to external noise and
reduce artifacts.
7. Which response indicates nerve irritation during free-running
EMG?
A. Loss of signal
B. Bursts of activity
C. Increased amplitude of SSEPs
D. Reduced signal latency
Answer: B
