EEG Activation Procedures 2

Question 1

During hyperventilation activation in EEG, what is the expected normal response in an adult?

Accepted Answer

Generalized slowing that resolves within 1-2 minutes after cessation

Answer

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.

Question 2

Photic stimulation at what flash frequency range is most likely to provoke a photoparoxysmal response in susceptible individuals?

Accepted Answer

15-20 Hz

Answer

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.

Question 3

Which of the following is a contraindication for performing hyperventilation during an EEG?

Accepted Answer

Recent cerebrovascular accident

Answer

Recent stroke is a contraindication for hyperventilation because the resulting hypocapnia and cerebral vasoconstriction could worsen ischemia in vulnerable brain tissue.

Question 4

What is the recommended duration for hyperventilation during a routine EEG recording?

Accepted Answer

3 minutes

Answer

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.

Question 5

What EEG finding during photic stimulation represents a normal physiological response?

Accepted Answer

Photic driving response in occipital regions

Answer

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.

EEG - Electroencephalography Practice Test

EEG - Electroencephalography Practice Test

EEG Activation Procedures 2