1 / 54

PART III

PART III. THE USE OF EEG Epilepsy Periodic patterns Other. 1. Epilepsy. 1. Yield after single seizure 50% (at best) higher if done sooner increases up to 80% with 4 th EEG 2. Epileptic abnormalities seen in approx. 0.5% of normals 2-14% with migraine, prior trauma, etc… 5-8% children

fiona
Download Presentation

PART III

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. PART III THE USE OF EEG Epilepsy Periodic patterns Other

  2. 1. Epilepsy 1. Yield after single seizure 50% (at best) • higher if done sooner • increases up to 80% with 4th EEG 2. Epileptic abnormalities seen in approx. 0.5% of normals • 2-14% with migraine, prior trauma, etc… • 5-8% children • 35% siblings of epileptics 3. Poor predictive value AAN practice parameter Neurology 2007; 69: 1996

  3. International classification of epilepsies Localization – idiopathic e.g. benign rolandic Localization – symptomatic/cryptogenic e.g. TLE Generalized – idiopathic e.g. JME Generalized – symptomatic/cryptogenic e.g. Lennox-Gastaut Age of onset Seizure Type(s) Family History Exam/Imaging EEG Epilepsia 2001; 42:796. 4. EEG most useful to classify the epileptic syndrome

  4. Epilepsy cont… King et al. Lancet 1998; 352: 1007 • Syndrome diagnosed clinically in 47% • With EEG, 77% • EEG within 24hr, 51% vs. 34% • Initial EEG 43%, after SD-EEG 61%

  5. Epilepsy cont… • Therefore…use the EEG to classify the epileptic syndrome, not to diagnose seizures • e.g. TLE vs. JME

  6. 2. Periodic Patterns Stereotypical sharp complexes repeating at a constant time interval for most or all of the recording.

  7. Periodic Stereotypical Sharp Repeating Constant time interval Most of the recording

  8. Rhythmic • Rhythm = “the regular, measured flow of sound…or action” • Rhythmic activity can be brief, and is continuous Hirsch et al. J Clin Neurophysiol 2005

  9. Periodic Patterns cont… • UNILATERAL PLEDs, Status • BILATERAL • Short latency (<4 sec) Triphasic waves, periodic complexes (of CJD) BiPLEDs, Status • Long latency (>4 sec) Burst-suppression, SSPE

  10. Alternatively… • PLEDs • BiPLEDs • GPEDs • Status, periodic complexes (CJD), SSPE, burst-suppression etc… • triphasic waves??

  11. PLEDs • Considered to be an interictal epileptic pattern (but strongly assoc. with seizures) • BiPLEDs occur independently over both hemispheres

  12. PLEDs

  13. Same patient (change timescale)

  14. Periodic Complexes of CJD • Can be biphasic, triphasic etc… • Can be unilateral initially • Not seen in nvCJD, FFI, only 10% other genetic CJD, rarely with v/v @ codon 129 • Distinguish from triphasic waves based on clinical context • Distinguish from PLEDs or status by reaction to stimuli, disappearance with sleep

  15. Periodic complexes in CJD (from Ebersole and Pedley)

  16. Periodic complexes in CJD (poor example)

  17. Triphasic waves • Toxic-metabolic encephalopathy • Typical of (but not specific for) hepatic encephalopathy

  18. Triphasic waves (Fisch and Spehlmann)

  19. Triphasic waves

  20. Burst-suppression

  21. Burst-suppression

  22. SSPE from Ebersole & Pedley)

  23. Status Chong J Clin Neurophysiol 2005 adapted from Young Neurology 1996

  24. Status NCSE post-arrest

  25. 3. Other • Coma • Brain death • EEG not indicated in headache* • Can consider in certain situations (pregnancy • EEG not useful in syncope • 2003-2007 JGH 517 EEG’s for syncope, LOC, or fall • 57 abnormal (0 epileptic, 6 potentially epileptic) • Only 5 changed management *Neurology 1995;45:1263 Neurology 2002;59:490 **Arch Int Med 1990;150:2027

  26. PART IV SLIDESHOW

  27. 3 Hz spike and wave with hyper

  28. Focal interictal epileptic activity (right anterior temporal)

  29. Cont… next page

  30. Generalized interictal epileptic activity

  31. Burst-suppression

  32. Cont…next page

  33. Focal seizure (glioma)

  34. PLEDS

  35. (Focal) non-convulsive status

  36. Hypsarrythmia with infantile spasm

  37. BECRS

  38. Burst-suppression post-arrest

  39. Triphasic waves

  40. Periodic complexes in CJD (from Fisch and Spehlmann)

  41. Focal slowing and epileptic activity, patient with sepsis

  42. Independent seizures 37 week HIE Ebersole and Pedley

  43. Cz-C3 Sp1-Sp2 Cz-C4 EOG Fp1-F7 T5-O1 Fp2-F8 T6-O2 Asystole secondary to a seizure

  44. Cont…next page

  45. PLEDS I year post TBI

  46. REVIEW

  47. TAKE-HOME MESSAGE 1. To read an EEG: -orient yourself -have an approach -describe what you see

  48. TAKE-HOME MESSAGE 2. The EEG is prone to artifact. Findings such as epileptic activity or focal slowing are often a judgement call, and can be seen in normal people. Therefore, the EEG is not absolute.

  49. TAKE-HOME MESSAGE 3. The EEG is not good at diagnosing or “ruling-out” seizures. It is far more useful for correctly classifying the epileptic syndrome.

  50. TAKE-HOME MESSAGE 4. Exam questions will not be subtle (No artifacts, no subtle focal slowing)

More Related