EEG - Electroencephalography Normal EEG Waveforms Questions and Answers

Question 1

An EEG recording of a relaxed, awake adult with eyes closed shows a prominent 8-13 Hz rhythm in the occipital regions.
This rhythm attenuates with eye opening.
Which of the following best identifies this waveform?

Accepted Answer

Alpha rhythm

Answer

Mu rhythm

Answer

Beta rhythm

Answer

Theta rhythm

Question 2

During a routine EEG on a 25-year-old patient, the technologist observes intermittent bursts of 7-11 Hz, arch-shaped waves over the central head regions (C3, C4, Cz). This activity disappears when the patient is asked to make a fist. What normal EEG variant is being described?

Accepted Answer

Mu rhythm

Answer

Lambda waves

Answer

Sleep spindles

Answer

Posterior slow waves of youth

Question 3

A technologist is reviewing an EEG from an awake patient who was asked to scan a complex image. The recording shows bilateral, positive, sharply contoured waves in the occipital channels that occur only during the visual scanning task. These waveforms are most likely:

Accepted Answer

Lambda waves

Answer

Positive Occipital Sharp Transients of Sleep (POSTS)

Answer

Epileptiform discharges

Answer

Vertex waves

Question 4

Which of the following statements is true regarding beta activity in a normal adult EEG?

Accepted Answer

It is often enhanced fronto-centrally by drowsiness or certain medications like benzodiazepines.

Answer

It is typically highest in amplitude in the occipital regions.

Answer

It is defined as activity in the 4-7 Hz frequency range.

Answer

It is always considered an abnormal finding in an awake adult.

Question 5

In a healthy, awake adult, the presence of excessive, generalized, and persistent theta activity (4-7 Hz) would most likely be interpreted as:

Accepted Answer

Evidence of cerebral dysfunction.

Answer

A normal variant during hyperventilation.

Answer

An indicator of deep relaxation.

Answer

A normal posterior dominant rhythm.

Question 6

The posterior dominant rhythm (PDR) in a healthy 8-year-old child is expected to have a frequency of approximately:

Accepted Answer

9 Hz

Answer

4-5 Hz

Answer

6-7 Hz

Answer

11-12 Hz

An EEG recording of a relaxed, awake adult with eyes closed shows a prominent 8-13 Hz rhythm in the occipital regions.This rhythm attenuates with eye opening.Which of the following best identifies this waveform?

An EEG recording of a relaxed, awake adult with eyes closed shows a prominent 8-13 Hz rhythm in the occipital regions.
This rhythm attenuates with eye opening.
Which of the following best identifies this waveform?