ACNS Guidelines – SSEPs Questions With Verified Answers Update

ACNS Guidelines – SSEPs Questions With Verified Answers Update What is the recommended contact impedence? - ANSWER < 5KOhms Where should a ground electrode be placed to reduce stimulus artifact? - ANSWER On the stimulated limb What types of pulses should be delivered? - ANSWER Monophasic rectangular A constant ________ or constant ___________ stimulator should be used. - ANSWER current ; voltage Pulse width should be - ANSWER 100-300 usec Stimulation rate should be - ANSWER 3-5Hz Most laboratories utilize a system passband of approximately _________ ? - ANSWER 30-3,000 Hz What is the advantage of using a wider passband? For example, extending down to 1Hz. What is the disadvantage? - ANSWER Allows one to record long duration signals. Introduces additional low-frequency noise that requires averaging more responses; prolonging recording time. In what scenario is more than two replications required to ensure that the responses represent stimulus-locked signals and not noise? - ANSWER For a high noise recording. What are two of the most troublesome sources of noise in EP recordings? - ANSWER Muscle activity Patient movement What are the minimal amount of channels to record SSEPs? - ANSWER 4 EP (N11) is the propagated volley passing under __________. - ANSWER Erb's point N13 is the stationary __________ potential. Recorded from the _____________. Reflects mainly postsynaptic activity in the ______________. - ANSWER cervical dorsal neck cervical cord P14 is a subcortically generated __________ potential. Recorded referentially from the ____________. Reflects activity in the caudal ______________. - ANSWER far-field scalp medial lamniscus