Syncope

Distinguishing syncope from Seizure

 

Seminal paper – Thijs et al. Neurology 90(15) pg 1339 - 2018

•   65 patients with tilt induced syncope compared to video EEG patients with focal epilepsy and convulsive seizures

 

 

Syncope

Seizures

Myoclonic jerks

51%

100%

Bilateral jerks

78%

100%

Bilateral synchrony

48%

90%

Number of jerks- median (range)

2 (1-19)

48 (20-191)

Clonic period (sec) median(range)

3.6 (0.4-43)

29 (10-72)

Rhymicity (MCD)

0.67 (low)

0.12 (high)

Tonic postures

65%

100%

Bilateral postures

76%

100%

Loss of tone

100%

0%

 

 

 

 

 

 

 

 

Insert table from article

 

Myoclonic jerk 10/20 rule

•   Less than 10 jerk – almost certainly syncope

•   Greater than 20 jerks – almost certainly seizure

EEG in Syncope

•   On EEG slowing is often seen during syncope and can be associated with myoclonic jeks

•   Flattening of the EEG is associated with tonic posturing.