1. Abnormal EEG brain in neurological disease
แพทย์หญิง กาญจนา พิทักษ์วัฒนานนท์
อายุรแพทย์ผู้เชี่ยวชาญระบบประสาท
แพทย์ประจำศูนย์สมอง โรงพยาบาลสมิติเวชศรีราชา

2. 10 – 20 system

3. Records the difference between two Active scalp electrodes
Bipolar montage

4. Referential montage Active scalp electrode
Inactive scalp / ear electrode : A1 , A2
Referential montage

5. Reference / Bipolar montage

6. If the voltage input from electrode 2 is relatively “ positive ” compared to electrode 1 ,
then the pen will deflect “ up ”
If electrode 2 is relatively “ negative ” compared to electrode 1 ,
then the pen will deflect “ down ”
If electrode 1 equal to electrode 2 ,
then the pen stay “ baseline ”
Polarity

7. Different Montage : Polarity

8. EEG interpretation Identify background rhythms ( frequency )
Alpha Hz
Beta 13 – 40 Hz
Theta 4 – 8 Hz
Delta < 4 Hz
Mu 7 – 11 Hz
Sleep stage ( awake , NREM , REM )
Identify any abnormal patterns
Slow patterns
Diffusely , Focally
Symmetry , Asymmetry
Paroxysms
Spike , spike and wave complex , sharp wave
Triphasic waves
PLEDs ( Periodic lateralizing epileptiform discharges )
Localize those abnormal patterns
Maximum amplitude ( Referential montage )
Phase reversal / Reciprocal changes ( Bipolar montage )
EEG interpretation

9. Background rhythm / frequency

10. Sleep stage : Background

11. Epilepsy

12. Factor lowering seizure threshold
Common
Sleep deprivation ,
Alcohol withdrawal ,
Television flicker ,
Systemic infection , Head trauma ,
Recreational drugs , antiepileptic drug ,
Menstruation
Occasional
Dehydration ,
Barbiturate / Benzodiazepine withdrawal ,
Hyperventilation ,
Flashing lights ,
Diet and missed meals ,
Specific reflex trigger ,
Stress , Intense exercise
Factor lowering seizure threshold

13. Activation tecniques ( EEG )
Rountine electroencephalograms
Hyperventilation
Photic stimulation
Sleep-deprivation
Prolonged ambulatory recording
Video – EEG telemetry
Magnetoencephalography : Research
Activation tecniques ( EEG )

14. Seizure

15. Epileptiform discharge / Spike

16. Focal seizure : spike ( phase reversal )

17. Herpes simple encephalitis
PLEDs ( Periodic lateralizing epileptiform discharges )
Herpes simple encephalitis

18. Ictal EEG : Spike and waves complexs

19. Generalized seizure

20. Absence seizure
3 Hz spike and wave complexs

21. Syndrome of epilepsy

22. Syndrome of epilepsy

23. CJD – Mad cow disease
Diffused slow pattern : encephalopathy

24. Prion encephalitis
Triphasic waves

25. Severe dementia
Triphasic waves : degenerative disease

26. Encephalopathy

27. Comatose

28. Brain death

29. Sleep or Death

30. Sleep Spindle

31. Sleep spindle / K complex

32. Sleep

33. Sleep Lab / Polysomnography

34. Hypnogram

35. Eye Blink Artifact

36. Artifact