CNIM Electroencephalography (EEG) in the Operating Room 2

Question 1

Burst suppression on intraoperative EEG is BEST described as:

Accepted Answer

Alternating periods of complete electrocerebral silence and bursts of mixed-frequency activity

Answer

Burst suppression consists of alternating episodes of electrical silence (suppression) and bursts of activity, reflecting profound but reversible cerebral metabolic depression.

Question 2

During carotid endarterectomy, which EEG change is MOST indicative of cerebral ischemia following carotid cross-clamping?

Accepted Answer

Unilateral amplitude reduction and frequency slowing ipsilateral to the clamp

Answer

Ipsilateral amplitude decrease and new delta slowing after carotid clamping are the classic EEG signs of inadequate hemispheric perfusion, prompting shunt placement.

Question 3

Which anesthetic agent is most associated with producing epileptiform EEG discharges during induction?

Accepted Answer

Etomidate

Answer

Etomidate can elicit myoclonic movements and cortical epileptiform discharges on EEG during induction, requiring careful distinction from pathological seizure activity.

Question 4

As anesthetic depth progressively increases, the general EEG pattern shifts:

Accepted Answer

From faster frequencies (beta/alpha) toward slower frequencies (theta then delta)

Answer

Increasing anesthetic depth progressively slows the EEG from fast beta activity through theta to delta dominance, and ultimately to burst suppression at very deep levels.

Question 5

At typical surgical maintenance doses of propofol (TIVA), the characteristic EEG pattern is:

Accepted Answer

Alpha oscillations and spindle-like beta activity (the 'propofol alpha')

Answer

Propofol at maintenance doses produces a distinctive anteriorly dominant alpha/beta oscillatory pattern, sometimes called the 'propofol alpha,' reflecting its unique GABAergic mechanism.

CNIM - Certification for Neurophysiological Intraoperative Monitoring Practice Test

CNIM - Certification for Neurophysiological Intraoperative Monitoring Practice Test

CNIM Electroencephalography (EEG) in the Operating Room 2