Contents

Search

electroencephalography (EEG)

Indications: 1) diagnosis of convulsive disorders a) evaluation of epilepsy, seizures - evaluation of non-convulsive status epilepticus in hospitalized elderly with refractory delirium [8] b) evaluation for epilepsy surgery 2) infantile spasm [4] 3) viral encephalitis 4) Creutzfeldt-Jakob disease 5) evaluation of coma Procedures: 1) wake-sleep EEG after sleep deprivation a) chloral hydrate 500-1000 mg for sedation on call to the EEG lab b) < 2 hours of sleep overnight preceding the EEG c) epileptiform discharges 1] may be seen in the waking state 2] sometimes more clearly detected in drowsiness of stage 2 sleep c) activation procedures can unmask seizure foci 1] hyperventilation 2] photic stimulation) d) T1 & T2 leads assess activity over the temporal lobes 2) awake EEG -> delirium &/or dementia-related encephalopathy 1] abnormal slow wave activity 2] paroxysmal discharges 3] global vs focal abnormalities 3) QEEG mapping 4) polysomnography or sleep EEG 5) 60 of minutes EEG recording for capturing events of clinical significance [7] Interpretation: Patterns: 1) Herpes simplex encephalitis: - periodic lateralizing epileptiform discharges emanating from the temporal lobes 2) hepatic encephalopathy: - triphasic waves 3) Creutzfeldt-Jacob disease: - bilateral synchronous repetitive sharp waves Clinical significance: - 40-50% sensitive in diagnosing epilepsy [1] - 7% of general medical inpatients in 1 study had seizures on EEG [3] - burst suppression pattern on electroencephalogram is a sensitive early marker (48 hours) of poor outcome (no sedation) in comatose patients

Related

electrocorticography polysomnography (PSG)

Specific

electrocorticogram at surgery electroencephalography during extracranial surgery electroencephalography for coma electroencephalography for seizure Fastball EEG Neuropsychiatric EEG-Based Assessment Aid (NEBA)

General

electrophysiologic measurement

References

  1. Medical Knowledge Self Assessment Program (MKSAP) 11, 19. American College of Physicians, Philadelphia 1998, 2021
  2. Dr. Cook's guide to ordering EEG tests. MentalHealth@ucla-edu
  3. Betjemann JP et al. Diagnostic yield of electroencephalography in a general inpatient population. Mayo Clin Proc 2013 Apr; 88:326 PMID: 23541007
  4. Deprecated Reference
  5. Claassen J, Taccone FS, Horn P et al Recommendations on the use of EEG monitoring in critically ill patients: consensus statement from the neurointensive care section of the ESICM. Intensive Care Med. 2013 Aug;39(8):1337-51 PMID: 23653183
  6. Kennedy JD, Gerard EE. Continuous EEG monitoring in the intensive care unit. Curr Neurol Neurosci Rep. 2012 Aug;12(4):419-28. PMID: 22653639
  7. Burkholder DB et al. Routine vs extended outpatient EEG for the detection of interictal epileptiform discharges. Neurology 2016 Mar 16; PMID: 26984946
  8. NEJM Knowledge+. Question of the Week. Oct 11, 2016 http://knowledgeplus.nejm.org/question-of-week/1296/
  9. Herman ST, Abend NS, Bleck TP et al Consensus statement on continuous EEG in critically ill adults and children, part I: indications. J Clin Neurophysiol. 2015 Apr;32(2):87-95. PMID: 25626778 Free PMC Article - Herman ST, Abend NS, Bleck TP et al Consensus statement on continuous EEG in critically ill adults and children, part II: personnel, technical specifications, and clinical practice. J Clin Neurophysiol. 2015 Apr;32(2):96-108. PMID: 25626777 Free PMC Article
  10. Booth CM, Boone RH, Tomlinson G, Detsky AS. Is this patient dead, vegetative, or severely neurologically impaired? Assessing outcome for comatose survivors of cardiac arrest. JAMA. 2004 Feb 18;291(7):870-9. Review. PMID: 14970067
  11. Wijdicks EF, Hijdra A, Young GB, Bassetti CL, Wiebe S; Quality Standards Subcommittee of the American Academy of Neurology. Practice parameter: prediction of outcome in comatose survivors after cardiopulmonary resuscitation (an evidence-based review): report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology. 2006 Jul 25;67(2):203-10. PMID: 16864809 Review.