Download Abnormal EEG brain in neurological disease

Abnormal EEG brain in
neurological disease
แพทย์หญิง กาญจนา พิทกั ษ์วฒ
ั นานนท์
อายุรแพทย์ผเู ้ ชี่ยวชาญระบบประสาท
แพทย์ประจาศูนย์สมอง โรงพยาบาลสมิติเวชศรีราชา
10 – 20 system

Records the difference between two Active
scalp electrodes
Bipolar montage
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
Active scalp electrode
Inactive scalp / ear electrode : A1 , A2
Referential montage
Reference / Bipolar montage
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
Different Montage : Polarity

Identify background rhythms (
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frequency
Alpha
8 -13 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
Background rhythm / frequency
Sleep stage : Background
Epilepsy

Common
◦ Sleep deprivation
◦
◦
◦
◦
◦
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,
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

Rountine electroencephalograms
◦ Hyperventilation
◦ Photic stimulation
◦ Sleep-deprivation

Prolonged ambulatory recording
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Video – EEG telemetry

Magnetoencephalography : Research
Activation tecniques ( EEG )
Seizure
Epileptiform discharge / Spike
Focal seizure :
spike
(
phase reversal
)
PLEDs ( Periodic lateralizing epileptiform discharges )
Herpes simple encephalitis
Ictal EEG
: Spike and waves complexs
Generalized seizure
Absence seizure
3 Hz spike and wave complexs
Syndrome of epilepsy
Syndrome of epilepsy
CJD – Mad cow disease
Diffused slow pattern : encephalopathy
Triphasic waves
Prion encephalitis
Severe dementia
Triphasic waves : degenerative disease
Encephalopathy
Comatose
Brain death
Sleep or Death
Sleep Spindle
Sleep spindle / K complex
Sleep
Sleep Lab / Polysomnography
Hypnogram
Eye Blink Artifact
Artifact