SSEPs and VEPs - CNIM Exam
Questions & Answers (Grade A+)
Somatosensory Evoked Potentials (SSEPs) -
correct answer ✅-Assesses somatosensory system functioning.
-Usually uses bipolar trancutaneous electrical electrical stimulation
of the medial nerve (MN) or the posterior tibial nerve (PTN), then
recording from the scalp.
Non-Pathologic Factors that Affect SSEPs -
correct answer ✅-Motor/Sensory Threshold
-Adequacy of peripheral nerve response
-Equalizing peripheral nerve response
-Filter effects
-Limb temperature and length
-Anesthetic
Motor/Sensory Threshold -
correct answer ✅-If threshold is too low, it may be difficult to elicit
a wave in absence of muscle relaxant.
Adequacy of Peripheral Nerve Response -
correct answer ✅-Measured for adequacy by measuring potential
at Erb's Point and the Popliteal Fossa.
, SSEPs and VEPs - CNIM Exam
Questions & Answers (Grade A+)
-Nerves are considered saturated when waveform amplitude is
unaffected by continuing increase of stimulation.
Filter Effects -
correct answer ✅-Phase lead (low frequency filter) and phase lag
(high frequency filter) effects are present in SSEPs.
-Lower the number, later the latency.
-Notch filter should only be used in extreme cases of 60 Hz
interference, as it affects waveform latency and amplitude.
-BAEPs also affected.
Limb Temperature and Length -
correct answer ✅-Waveform latency and amplitude affected by
temperature.
-Increased latency with increased limb length.
-Temperature affects conduction velocity of neuron.
Anesthetic Factors -
correct answer ✅-Affect SSEP recordings and BAEP recordings.
-SSEPs more affected because they are recorded from sensory
cortex and not the brainstem. Sensory cortex more affected by
anesthetics.
Questions & Answers (Grade A+)
Somatosensory Evoked Potentials (SSEPs) -
correct answer ✅-Assesses somatosensory system functioning.
-Usually uses bipolar trancutaneous electrical electrical stimulation
of the medial nerve (MN) or the posterior tibial nerve (PTN), then
recording from the scalp.
Non-Pathologic Factors that Affect SSEPs -
correct answer ✅-Motor/Sensory Threshold
-Adequacy of peripheral nerve response
-Equalizing peripheral nerve response
-Filter effects
-Limb temperature and length
-Anesthetic
Motor/Sensory Threshold -
correct answer ✅-If threshold is too low, it may be difficult to elicit
a wave in absence of muscle relaxant.
Adequacy of Peripheral Nerve Response -
correct answer ✅-Measured for adequacy by measuring potential
at Erb's Point and the Popliteal Fossa.
, SSEPs and VEPs - CNIM Exam
Questions & Answers (Grade A+)
-Nerves are considered saturated when waveform amplitude is
unaffected by continuing increase of stimulation.
Filter Effects -
correct answer ✅-Phase lead (low frequency filter) and phase lag
(high frequency filter) effects are present in SSEPs.
-Lower the number, later the latency.
-Notch filter should only be used in extreme cases of 60 Hz
interference, as it affects waveform latency and amplitude.
-BAEPs also affected.
Limb Temperature and Length -
correct answer ✅-Waveform latency and amplitude affected by
temperature.
-Increased latency with increased limb length.
-Temperature affects conduction velocity of neuron.
Anesthetic Factors -
correct answer ✅-Affect SSEP recordings and BAEP recordings.
-SSEPs more affected because they are recorded from sensory
cortex and not the brainstem. Sensory cortex more affected by
anesthetics.
