EEG Routine 4 — Questions and Answers
Question 1: During a routine EEG, how long should a standard hyperventilation activation procedure last?
- 1 minute
- 3 minutes (Correct answer)
- 5 minutes
- 10 minutes
Correct answer: 3 minutes
Standard hyperventilation during routine EEG lasts 3 minutes, followed by at least 1 minute of continued recording.
Question 2: Which electrode placement system is universally used for routine EEG recordings?
- Queen Square system
- 10-20 International System (Correct answer)
- Laplacian montage
- Bipolar transverse system
Correct answer: 10-20 International System
The 10-20 International System is the universally accepted standard for electrode placement in routine EEG.
Question 3: What is the minimum recommended duration for a routine outpatient EEG recording in an adult?
- 10 minutes
- 20 minutes (Correct answer)
- 30 minutes
- 60 minutes
Correct answer: 20 minutes
A routine adult outpatient EEG should last at least 20 minutes of artifact-free recording to be diagnostically adequate.
Question 4: When applying EEG electrodes using collodion, what substance is used to remove them after the recording?
- Isopropyl alcohol
- Acetone (Correct answer)
- Saline solution
- Electrode gel
Correct answer: Acetone
Acetone is used to dissolve collodion and safely remove electrodes from the scalp after the EEG recording.
Question 5: Which EEG feature is a normal finding in drowsiness in adults?
- K-complexes
- Posterior slow waves of youth
- Vertex sharp waves (Correct answer)
- Sleep spindles
Correct answer: Vertex sharp waves
Vertex sharp waves (V waves) are normal transients that appear over the vertex during drowsiness and light sleep.
Question 6: In a routine EEG, what is the purpose of the 'photic driving' response during photic stimulation?
- To induce seizures in all patients
- To assess cortical reactivity to visual stimuli (Correct answer)
- To replace the need for hyperventilation
- To measure auditory evoked potentials
Correct answer: To assess cortical reactivity to visual stimuli
Photic driving assesses the cortex's ability to follow and respond to rhythmic visual stimuli, reflecting posterior cortical reactivity.
Question 7: What impedance level is considered acceptable for EEG electrodes before starting a recording?
- Below 500 ohms
- Below 5,000 ohms (5 kΩ) (Correct answer)
- Below 50,000 ohms
- Below 100 kΩ
Correct answer: Below 5,000 ohms (5 kΩ)
Electrode impedances should be below 5 kΩ (and ideally matched between electrodes) to ensure low-artifact, high-quality recordings.
EEG Routine 4
During a routine EEG, how long should a standard hyperventilation activation procedure last?