Common EEG Artifacts & Their Identification

Question 1

Name 7 Common EEG artifacts

Answer 1

Muscle, Eye Movement, Electrode Popping/Movement, Environmental Noise, Electrode Impedance, Sweating/Salt Bridge, Electrical Interference

Question 2

What are examples of muscle artifact?

Answer 2

eye blinks, eye movement, jaw clenching, facial movements, body twitches

Question 3

True/False - muscle artifacts appears as low amplitude wave forms

Answer 3

False

Question 4

How do muscle artifacts appear as waves?

Answer 4

As sharp, spiky waves that coincide with the timing of the muscle activity

Question 5

What is the fix for muscle artifacts?

Answer 5

Try to calm the patient. Change the high frequency to check if the activity attenuates and make notations

Question 6

What causes eye movement artifacts?

Answer 6

Eye movement artifacts are caused by rapid eye movements (saccades) or slow eye drifts during wakefulness or rapid eye movement (REM) sleep

Question 7

How do eye movement artifacts appear as waves?

Answer 7

They appear as slow waves or sharp deflections, often with horizontal or vertical orientation

Question 8

Where are the eye movement artifacts commonly seen?

Answer 8

In the frontal or prefrontal electrode channels

Question 9

When does electRode popping (or movement) occur?

Answer 9

When electrodes become loose resulting in intermittent loss of contact or displacement from the scalp

Question 10

How do electrode popping or movement manifest as waves?

Answer 10

As abrupt signal loss or fluctuating amplitudes often affecting specific channels

Question 11

What is the fix for electrode popping?

Answer 11

Rescrub or reapply electrode or replace if necessary

Question 12

What are the external source types that cause environmental noice artifacts?

Answer 12

Electrical equipment, power lines, electromagnetic fields, or radio frequency

Question 13

Describe the environmental noise artifacts

Answer 13

They can cause rhythmic or irregular disturbances across multiple channels and often appear as high frequency, low amplitude waves or irregular patterns unrelated to brain activity.

Question 14

What is the fix for environmental noise artifacts?

Answer 14

Check connection of cables to amplifiers

Question 15

What is electrode impedance?

Answer 15

Refers to the resistance encountered between the electrode and the scalp which affects the quality of the recorded signals

Question 16

What is the fix for electrode impedance issues?

Answer 16

Rescrub and reapply electrode - or replace if necessary

Question 17

What is common mode rejection?

Answer 17

It refers to the ability of an EEG system to reject unwanted signals that are present in equal measure at multiple electrodes

Question 18

How does the wave form look with sweating or salt bridge?

Answer 18

Inconsistent, erratic or attenuated signal

Question 19

What is the fix for sweating (or salt bridge) issues?

Answer 19

Clean between electrodes with alcohol and or turn temperature in the room down

Question 20

What is an electrical interference artifact.

Answer 20

Results from nearby electronic devices, power sources or faulty grounding

Question 21

How do electronic interference artifacts appear?

Answer 21

As regular, rhythmic, or repetitIve patterns across multiple channels manifesting as sharp waves, spikes for oscillations.

Question 22

What is the fix for electrical interference?

Answer 22

Let Pt and family know that personal devices may not be charging when in contact with patient or anything patient is sitting or lying on