Fig. 2

Results displayed ictal EEG and back-averaging of of the ictal EEG data. a and b. A visible spike wave at left central-parietal cortex immediately preceded a right myoclonic muscle activity,while a visible spike wave at right central-parietal cortex immediately preceded a left myoclonic muscle activity. c. A visible spike wave at left central-parietal cortex immediately preceded a right myoclonic muscle activity during sleep. d. Jerk-locked averaging discloses a pre-myoclonic negative peak predominantly at the central-parietal electrode; this peak precedes the EMG onset by approximately 42 ms. Electromyogram: on both deltoid muscles. The red line represents the abnormal electrical activity in the brain and burst of EMG activity. EEG: electroencephalogram