1. By: Mazen Al-Hakim, M.D.
Seizure mimics

2. Seizure Mimics
* A-clinical: -Syncope -“Pseudo-seizures” -Sleep disturbances -Hyperventilation -Metabolic * B. EEG Misreading

3. Syncope
1- Convulsive Syncope 2- Eyes rolled back 3- Staring 4- Incontinence

4. Prodrome of Syncope
Light-headed, blurred vision, pallor, sweating, nausea…

5. Seizure Prodrome Aura=Focal seizure Usually temporal: déjà vu
Jamais vu, rising sensation in abdomen,
abnormal smell or taste

6. Landmark Study of Syncope by Lempert et al, 1994
-Myoclonus is common -Head turning, automatism, hallucinations

7. Postictal is the most important
Syncope: No post-ictal encephalopathy
low blood pressure
Seizure: Amnesia, confusion, lethargy, agitation
High blood pressure, tongue biting

8. EEG in convulsive syncope
Slow, then flat line
No seizure

9. Pseudo seizures
30% of referral to video monitor for “intractable seizures”

10. Combination of Seizure and Pseudo seizure is uncommon
Underlying psychopathology and emotional trauma including sexual abuse

11. Clinical signs Stop and go activity Out of phase
Head turning right and left
Nonclonic shaking
Pelvic thrusting
Opisthotonic posturing
Vocalization: stuttering, weeping
Preserved awareness during bilateral motor activity
Ictal eye closure
Pseudosyncope
Postictal whispering
No postictal encephalopathy

12. Another 30% patient referred for intractable epilepsy had EEG misread as epileptic

13. The most common pattern is:
Nonspecific fluctuations of background in the temporal regions

14. Epileptic discharges
-clearly distinguished from background -pointed peak -spike: msec. -sharp wave: msec.

15. Maulsby’s Guidelines, 1971
1- Artifact until proven otherwise 2- Electrical field 3- Negative polarity 4- Followed by slow wave 5- Ignore simple alterations in voltage, or superimposed several components 6- Be familiar with “normal” sharp waves or spikes

16. Normal alpha in an adult EEG with a phase reversal at the T6 electrode derivation that was identified as “suspicious” for an epileptiform discharge (arrows)‏
with a phase reversal at the T6 electrode derivation that was identified as “suspicious” for an epileptiform discharge (arrows).
Normal alpha in an adult EEG with a phase reversal at the T6 electrode derivation that was identified as “suspicious” for an epileptiform discharge (arrows)‏
Tatum W O Neurology 2013;80:S4-S11
© 2013 American Academy of Neurology

17. Normal EEG in an 18-year-old showing a hypnagogic (“drowsy”) burst (oval) of paroxysmal theta and delta frequencies that appears sharply contouredThis reflects normal electrocerebral activity during sleep transition. Note the change in the EEG immediately after the burst to reflect the change in state. The “MARK” applied by the technologist signifies a “suspicious” burst.
ars sleep transition.
Normal EEG in an 18-year-old showing a hypnagogic (“drowsy”) burst (oval) of paroxysmal theta and delta frequencies that appears sharply contouredThis reflects normal electrocerebral activity during sleep transition. Note the change in the EEG immediately after the burst to reflect the change in state. The “MARK” applied by the technologist signifies a “suspicious” burst.
Tatum W O Neurology 2013;80:S4-S11
© 2013 American Academy of Neurology

18. bursts during the awake state in a 57-year-old (circles).
Wicket spikes appearing in repetitive bursts during the awake state in a 57-year-old (circles)‏
bursts during the awake state in a 57-year-old (circles).
Wicket spikes appearing in repetitive bursts during the awake state in a 57-year-old (circles)‏
Tatum W O Neurology 2013;80:S4-S11
© 2013 American Academy of Neurology

19. Rhythmic midtemporal theta bursts of drowsiness in the EEG of a young adultNote the sharply contoured waveform that mimics the appearance of bilateral bursts of repetitive temporal sharp waves (boxes).
Rhythmic midtemporal theta bursts of drowsiness in the EEG of a young adultNote the sharply contoured waveform that mimics the appearance of bilateral bursts of repetitive temporal sharp waves (boxes).
Tatum W O Neurology 2013;80:S4-S11
© 2013 American Academy of Neurology

20. Figure 8 Adult EEG demonstrating lambda waves during scanning eye movements (black arrows)Although the pattern may appear morphologically as a “sharp wave,” the location, positive polarity, and the relationship to scanning eye movements (reading) are distinctive.
Adult EEG demonstrating lambda waves during scanning eye movements (black arrows)Although the pattern may appear morphologically as a “sharp wave,” the location, positive polarity, and the relationship to scanning eye movements (reading) are distinctive. Note the disappearance of the lambda waves after eye closure (red arrows) with return of the normal alpha rhythm that further identifies this feature as a normal finding.
Tatum W O Neurology 2013;80:S4-S11
© 2013 American Academy of Neurology