CNIM Somatosensory Evoked Potentials (SSEP) 2

Question 1

Which filter settings are typically used for intraoperative SSEP recording?

Accepted Answer

30–3000 Hz bandpass

Answer

SSEP recordings typically use a bandpass filter of 30–3000 Hz to capture the relevant frequency components of evoked potential waveforms while reducing low-frequency drift and high-frequency noise.

Question 2

What is the recommended number of averages to obtain a reliable SSEP waveform in the operating room?

Accepted Answer

200–500

Answer

Typically 200–500 sweeps are averaged intraoperatively to achieve an acceptable signal-to-noise ratio for SSEP waveforms.

Question 3

Bilateral loss of SSEP signals with preserved baseline recordings most likely indicates:

Accepted Answer

A systemic physiological change such as hypotension or hypothermia

Answer

Simultaneous bilateral SSEP loss typically suggests a systemic cause such as severe hypotension, hypothermia, or anesthetic changes rather than a focal surgical injury.

Question 4

Which anesthetic agent has the least suppressive effect on cortical SSEP amplitudes?

Accepted Answer

Propofol-based total intravenous anesthesia (TIVA)

Answer

Propofol-based TIVA has the least suppressive effect on cortical SSEP amplitudes compared to volatile inhalational agents, making it preferred for cases requiring sensitive monitoring.

Question 5

The stimulation rate for median nerve SSEP should avoid multiples of 60 Hz to prevent:

Accepted Answer

Electrical line noise contamination

Answer

Stimulation rates that are multiples of 60 Hz can alias with power line frequency, contaminating the averaged SSEP with electrical noise rather than canceling it.

CNIM - Certification for Neurophysiological Intraoperative Monitoring Practice Test

CNIM - Certification for Neurophysiological Intraoperative Monitoring Practice Test

CNIM Somatosensory Evoked Potentials (SSEP) 2