EEG - Electroencephalography Artifact Identification Questions and Answers

Question 1

A technologist observes rhythmic, sharp-appearing transients that are most prominent in the left temporal channels and perfectly time-locked with the QRS complex on the EKG monitor.
What is the most likely artifact and the best initial step to resolve it?

Accepted Answer

EKG artifact; attempt to reposition the M1/A1 or T3 electrode slightly.

Answer

Pulse artifact; increase the low-frequency filter to 2 Hz.

Answer

IV drip artifact; check the patient's infusion pump for electrical noise.

Answer

60 Hz interference; ensure the notch filter is enabled.

Question 2

Which of the following EEG findings is most characteristic of a patient performing lateral eye movements to the right?

Accepted Answer

A slow positive deflection at F8 and a slow negative deflection at F7.

Answer

A sharp positive deflection at F7 and a sharp negative deflection at F8.

Answer

High-amplitude, synchronous slow waves in all frontal channels.

Answer

Rhythmic 8 Hz sinusoidal waves in the Fp1 and Fp2 channels.

Question 3

A patient is extremely anxious, resulting in contamination of the frontotemporal channels with persistent, high-frequency, irregular activity. Which of the following is the MOST effective first step a technologist should take to reduce this artifact?

Accepted Answer

Ask the patient to take a deep breath, relax their jaw, and let their mouth open slightly.

Answer

Apply the 60 Hz notch filter.

Answer

Increase the low-frequency filter setting to 5 Hz.

Answer

Re-prep the affected electrodes to lower their impedances.

Question 4

During an EEG on a febrile and diaphoretic patient, the technologist observes very slow, undulating, low-frequency (<0.5 Hz) waves that are widespread and cause the baselines of multiple channels to sway. This pattern is most characteristic of which type of artifact?

Accepted Answer

Sweat artifact

Answer

Respiration artifact

Answer

Glossokinetic artifact

Answer

Pulse artifact

Question 5

An EEG recording shows a sudden, very high-amplitude, brief transient that is strictly confined to a single channel. The transient does not have a physiological field and is not time-locked to any other event. What is the most likely cause?

Accepted Answer

An electrode artifact ('pop')

Answer

An EKG artifact

Answer

An epileptiform spike

Answer

A photic driving response

Question 6

Which of the following is the LEAST likely cause of persistent 60 Hz electrical interference in an EEG recording?

Accepted Answer

The patient's rhythmic chewing or teeth clenching.

Answer

A nearby unplugged piece of medical equipment in the room.

Answer

Unbalanced electrode impedances, with one being significantly higher than the others.

Answer

A frayed power cord on the EEG machine or patient's bed.

A technologist observes rhythmic, sharp-appearing transients that are most prominent in the left temporal channels and perfectly time-locked with the QRS complex on the EKG monitor.What is the most likely artifact and the best initial step to resolve it?

A technologist observes rhythmic, sharp-appearing transients that are most prominent in the left temporal channels and perfectly time-locked with the QRS complex on the EKG monitor.
What is the most likely artifact and the best initial step to resolve it?