EEG Artifact Identification 4

Question 1

A rhythmic artifact at exactly 60 Hz appearing uniformly across all electrodes is most consistent with:

Accepted Answer

AC line noise

Answer

60 Hz AC line noise appears as a uniform, rhythmic interference at power line frequency across all or many electrodes.

Question 2

Which artifact would most likely appear as a high-amplitude, low-frequency deflection time-locked to the R-wave on ECG?

Accepted Answer

Pulse artifact

Answer

Pulse artifact is caused by scalp vessel pulsations under electrodes and appears as slow deflections synchronous with the cardiac cycle.

Question 3

A technologist notices intermittent square-wave transients isolated to a single electrode that disappear when the electrode impedance is rechecked and re-gelled. This is most consistent with:

Accepted Answer

Electrode pop

Answer

Electrode pops are caused by intermittent loss of contact or impedance instability at a single electrode and typically resolve with re-application.

Question 4

Slow, sinusoidal, high-amplitude waves that wax and wane over frontal electrodes in a drowsy, diaphoretic patient are most characteristic of:

Accepted Answer

Sweat artifact

Answer

Sweat artifact produces slow (< 1 Hz), large-amplitude sinusoidal waves predominantly over frontal regions due to sweat gland activity.

Question 5

An artifact appearing as a rhythmic, 1–3 Hz broad, high-amplitude slow-wave pattern that correlates with the patient's assisted ventilation rate is called:

Accepted Answer

Ventilator artifact

Answer

Ventilator artifact is caused by rhythmic chest and head movement from mechanical ventilation, producing slow waves at the ventilation rate.

EEG - Electroencephalography Practice Test

EEG - Electroencephalography Practice Test

EEG Artifact Identification 4