EEG artifacts can arise from various physiological and extraphysiological sources other than brain activity. Physiological artifacts originate from the patient's own generator sources like eye movements, muscle activity, movement, and cardiac activity. Extraphysiological artifacts are externally generated, such as from medical devices, electrical equipment, or the environment. Common EEG artifacts include cardiac artifacts like ECG signals, ballistocardiographic artifacts from head or body movement, pacemaker signals, and pulse artifacts. Electrode artifacts can be transient pops or low frequency rhythms across electrodes from poor contact or movement. External artifacts include 50/60 Hz ambient noise, intravenous drips, and signals from devices like pumps and ventilators. Muscle and ocular artifacts

1. EEG ARTIFACTS
DR SRIRAMA ANJANEYULU
RESIDENT,NEUROLOGY
KING GEORGE HOSPITAL,VIZAG

2. Introduction
• Unwanted electrical activity arising from
different sources, other than cerebral activity.
• EEG -highly sensitive recording device, easily
interrupted by other electrical activity of very
high voltages .
• Some readily distinguished, others closely
resemble cerebral activity that their
interpretation is taxing even to the most
experienced eletroencephalographer.

3. CLASSIFICATION
Physiological : from patient’s own,generator sources
other than the brain.
– Eye movement
– Muscle ( EMG )
– Movement
– Cardiogenic
– Sweat
• Extraphysiological : Externally generated e.g.
instrumental & environmental.
- IV drip,
-ventilator

4. Cardiac artifacts
• ECG artifact-poorly formed QRS complex , left
temporal leads.(BETS,IED,PLEDS)
• Ballistocardiographic-movement of head or
body with cardiac contractions.
• Pacemaker-generalized across scalp , shorter
duration.
• Pulse-electrode resting on vessel , frontal and
temporal leads , follows ECG artifact.

5. Cardiac artifact

6. Cardiac artifact

7. Pacemaker artifact

8. Pulse artifact

9. ELECTRODE ARTIFACT-TYPES
• Two forms-brief transients limited to one
electrode , low frequency rhythms across scalp
region.
• Electrode pop-spontaneous discharges.
• Electrode contact-poor contact.
• Electrode/lead movement.
• Perspiration-undulating waves >2 sec.
• Salt bridge-lower amplitude.
• Movement artifact.

10. Electrode pop

11. Electrode Movement artifact

12. Lead movement

13. Sweat artifact

14. Salt bridge artifact

15. EXTERNAL DEVICE ARTIFACT
• 50/60 HZ ambient electrical noise
• Intravenous drip
• Electrical devices-intravenous pumps,
telephone
• Mechanical artifacts-ventilators,circulator
pumps

16. 60 Hz artifact

17. IV drip

18. Electrical motor

19. Mechanical ventilator

20. Circulatory pump

21. MUSCLE ARTIFACT
• Glossokinetic
• Photomyogenic
• Surface EMG

22. Muscle artifact

23. Muscle and movement artifact

24. EMG artifact

25. Photomyogenic artifact

26. OCULAR ARTIFACT
• Blink
• Eye flutter
• Lateral gaze
• Slow/rowing eye movements
• Lateral rectus spike

27. Blink artifact

28. Eye flutter artifact

29. Eye flutter artifact

30. Lateral eye movement

31. Slow roving eye movement

32. Lateral rectus spike

33. Thank you