Background

The background EEG is normal.

Interictal

Occipital spike or spike-and-wave may occur in the resting EEG record. Centrotemporal spikes may co-exist.

Activation

Occipital spike-and-wave or polyspike-and-wave is facilitated by intermittent photic stimulation when generalized spike-and-wave or polyspike-and-wave (with posterior predominance) may also occur. EEG abnormality is enhanced by sleep deprivation and by sleep.

Ictal

Occipital ictal patterns are seen, spread may occur to the ipsilateral temporal lobe.