Background/Interictal

The EEG background may be normal at onset, progressive slowing of the background occurs over time. Interictal EEG findings may vary depending on the underlying etiology.

Ictal

A single generalized polyspike-and-wave may correlate with the myoclonic seizure, or there may be variable ictal EEG findings.

With generalized tonic-clonic seizures, the ictal EEG is often obscured by artifact. Generalized fast rhythmic spikes are seen in the tonic stage. Bursts of spikes and after-coming slow waves are synchronous with clonic jerks. A postictal period of irregular slow activity follows.