The background EEG is normal.
Generalized spike- or polyspike-wave may be seen.
Generalized spike- or polyspike-wave may be activated in sleep.
Myoclonic seizures are associated with generalized spike-wave or polyspike-wave discharges at approximately 3Hz. They are more commonly recorded from sleep, and may be triggered by sudden noise or touch or by intermittent photic stimulation.