THE EEC FINDINGS IN EXTRATEMPORAL SEIZURES

Extratemporal seizures originate from the frontal, central, parietal, occipital, and midline regions of the brain. The scalp EEG can show va rious types of interictal and ictal discharges consisting of spikes, s pike and wave sharp waves, paroxysmal fast activity, or rhythmic activ ity in the beta, alpha, theta, or delta frequency ranges. The discharg es can occur as focal, regional, lateralized, or secondarily generaliz ed discharges. Discharges arising from the frontal region are varied a nd at times complex. Centro-temporal spikes associated with benign epi lepsy of childhood have a characteristic blunt spike and wave appearan ce. Centro-parietal spikes can occur in children with benign childhood epilepsy or in association with symptomatic epilepsies at any age. Oc cipital spike discharges have been seen in young children with visual problems, benign occipital epilepsy of childhood, the Sturge-Weber syn drome, and other symptomatic or structural lesions involving the occip ital lobe. There may be problems with detection of the source of origi n of seizures secondary to the anatomy of the various regions, deep fo ci, small restricted foci, rapid spread of epileptiform discharges, an d contaminating effects of muscle and movement artifact. Depth or intr acranial recordings may help in further localization of foci.