Electroencephalography

From Anvita Health Wiki

Contents 1 Indications 2 Procedure 3 Interpretation 4 More General Terms 5 Additional Terms 6 References

Indications

• diagnosis of convulsive disorders
• evaluation for epilepsy surgery
• viral encephalitis
• Creutzfeldt-Jakob disease

Procedure

• wake-sleep EEG after sleep deprivation

• chloral hydrate 500-1000 mg for sedation on call to the EEG lab
• < 2 hours of sleep overnight preceding the EEG
• epileptiform discharges

• may be seen in the waking state
• sometimes more clearly detected in drowsiness of stage 2 sleep

• activation procedures can unmask seizure foci

• hyperventilation
• photic stimulation)

• T1 & T2 leads assess activity over the temporal lobes

• awake EEG

• delirium &/or dementia-related encephalopathy

• abnormal slow wave activity
• paroxysmal discharges
• global vs focal abnormalities

• QEEG mapping
• polysomnography or sleep EEG

Interpretation

• Patterns:
• Herpes simplex encephalitis:

• periodic lateralizing epileptiform discharges emanating from the temporal lobes

• hepatic encephalopathy:

• triphasic waves

• Creutzfeldt-Jacob disease:

• bilateral synchronous repetitive sharp waves

More General Terms

• clinical procedure
• electrophysiologic measurement

Additional Terms

• polysomnography (PSG)

References

1. Medical Knowledge Self Assessment Program (MKSAP) 11, American College of Physicians, Philadelphia 1998
2. Dr. Cook's guide to ordering EEG tests. MentalHealth@ucla-edu
3. National Guideline Clearinghouse Guidelines for intraoperative neuromonitoring using raw (analog or digital waveforms) and quantitative electroencephalography. A position statement by the American Society of Neurophysiological Monitoring. ngc-guideline: [1]

electroencephalography (EEG)