EEG - Electroencephalography Electrode Placement and Montages Questions and Answers

Question 1

An EEG technologist is setting up for a routine adult EEG.
According to the International 10-20 System, what are the four primary anatomical landmarks used to ensure standardized and proportional electrode placement?

Accepted Answer

Nasion, inion, and both preauricular points

Answer

Nasion, inion, and both mastoid processes

Answer

Nasion, vertex, and both temporal lobes

Answer

Vertex, inion, and both zygomatic arches

Question 2

A patient's EEG recording shows a focal discharge. To best define the point of maximum electronegativity and pinpoint the origin of the activity, which type of montage is most effective?

Accepted Answer

Referential montage

Answer

Bipolar 'double banana' montage

Answer

Laplacian montage

Answer

Transverse bipolar montage

Question 3

In a longitudinal bipolar montage, often called a 'double banana', how are the electrodes connected?

Accepted Answer

In chains running from anterior to posterior regions of the head.

Answer

In chains running from the left to the right side of the head.

Answer

To a single common reference electrode, such as the vertex (Cz).

Answer

Each electrode is compared to a weighted average of its surrounding electrodes.

Question 4

Which of the following statements accurately describes the fundamental principle of a bipolar montage?

Accepted Answer

It measures the voltage difference between adjacent electrodes in a chain.

Answer

It measures the voltage difference between each electrode and a mathematically derived average of all electrodes.

Answer

It is designed to be less sensitive to localized abnormalities compared to referential montages.

Answer

It requires a non-cephalic reference to avoid contamination from brain activity.

Question 5

A technologist is reviewing an EEG on a digital system and wants to enhance the visualization of a very localized, focal discharge while minimizing the influence from distant, widespread activity. Which montage would be the most appropriate choice?

Accepted Answer

Laplacian montage

Answer

Contralateral ear reference montage

Answer

Longitudinal bipolar montage

Answer

Average reference montage

Question 6

According to the 10-20 International System nomenclature, which electrode would be located over the left mid-temporal region?

Accepted Answer

T3

Answer

T4

Answer

C3

Answer

Pz

An EEG technologist is setting up for a routine adult EEG.According to the International 10-20 System, what are the four primary anatomical landmarks used to ensure standardized and proportional electrode placement?

An EEG technologist is setting up for a routine adult EEG.
According to the International 10-20 System, what are the four primary anatomical landmarks used to ensure standardized and proportional electrode placement?