1. Chih Ho Chou Department of neurology
EEG
Chih Ho Chou
Department of neurology

2. EEG Physiology
Distrubuted neuronal networks assure correct functioning of the human brain.
Inhibitory and excitatory feedforward and feedback processes are basic mechanisms

3. Basic Interpretation
Standard or system
Awake and resting

7. Montage Reference montage Bipolar montage
Anterior-posterior bipolar montage (double banana montage)
Transverse montage (E-montage)
C-montage
A1-A2 montage

8. Calibration Time constant Sensitivity: 紀錄腦死時sensitivity 需提高至 2 μV/mm
Amplitude linearity

9. Frequency filter 低頻截頻器: 濾去過慢頻率之腦波 ( sweating…)
高頻截頻器: 濾去過快頻率之腦波 (muscular artifacts…)
Notch filter:濾去 60 Hz 交流電

10. Normal rhythms  rhythm (8-13 Hz occipital region, visual blocking)
 rhythm (14-30 Hz) classification of frontal, widespread type, and posterior type (sometimes called fast alpha variant because of visual blocking)
γ rhythm (>30), very low amplitude, technically difficult to study. Cognitive activity “dynamic”

11.  rhythm (sharp transient of sawtooth shape and of pasitive polarity in the pccopital regions, looking at image containing visual details. VEP)
Mu rhythm (arch-shaped, 7-11Hz, paracentral area, blocked by voluntary or passive movements)

12. Abnormal activities
δ activity (4-7 Hz)
Θ activity (<3 Hz)

13. Artifacts Physiologic effects 1.from cardiovascular system
EKG artifact
pulse artifact
ballistocardiogram
2.respiratory artifact
3.sweating artifact

14. 4. EMG artifact
5. Eye movement artifact
6. glossokinetic artifact
7. body movement artifact

15. Mechanical artifact
electrode pop
60 Hz artifact
Environmental artifact
static electricity
plug artifact

16. Activation procedure Chemical activation hyperventilation
drug: diazepam…
Input modification
photic stimulation
auditory
somatic
State related to biological rhythm
sleep
sleep deprivation

17. 懷疑為absence seizure, 一定要做hyperventilation
懷疑為juventile myoclonic epilepsy, 一定要做photic stimulation
懷疑為temporal seizure, 一定要做 sleep EEG

18. 癲癇發作怎麼辦?
立即停止誘發
保護病人為原則
不必硬塞東西到患者口中
不必強壓患者手腳
不必馬上送急診, 除非是大發作癲癇重積狀 態