Activation Procedures Flashcards
6 cards from real EEG practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Activation Procedures flashcards as text
During hyperventilation activation in EEG, what is the expected normal response in an adult?
Answer: Generalized slowing that resolves within 1-2 minutes after cessation
Normal hyperventilation response in adults produces bilateral, symmetrical, generalized slowing (buildup) that resolves within 1-2 minutes of stopping. Persistent or asymmetric slowing is abnormal.
Photic stimulation at what flash frequency range is most likely to provoke a photoparoxysmal response in susceptible individuals?
Answer: 15-20 Hz
The photoparoxysmal response, characterized by generalized spike-and-wave or polyspike-and-wave discharges, is most commonly elicited at flash frequencies between 15-20 Hz.
Which of the following is a contraindication for performing hyperventilation during an EEG?
Answer: Recent cerebrovascular accident
Recent stroke is a contraindication for hyperventilation because the resulting hypocapnia and cerebral vasoconstriction could worsen ischemia in vulnerable brain tissue.
What is the recommended duration for hyperventilation during a routine EEG recording?
Answer: 3 minutes
Standard hyperventilation is performed for 3 minutes with continued recording for at least 1-2 minutes afterward to capture the recovery phase and any provoked abnormalities.
What EEG finding during photic stimulation represents a normal physiological response?
Answer: Photic driving response in occipital regions
Photic driving is a normal response where occipital rhythms entrain to the flash frequency. It represents normal visual cortex reactivity and should not be confused with pathological photoparoxysmal responses.
Sleep deprivation before an EEG is primarily used to:
Answer: Increase the likelihood of recording epileptiform discharges
Sleep deprivation is an activation procedure that increases the yield of detecting epileptiform abnormalities by promoting drowsiness and sleep, states in which interictal discharges are more likely to appear.