Periodic electroencephalographic patterns: usefulness of definition and classification

Abstract

identified a peri-odic and lateralized pattern, which they described as periodic lateralized epilepti-form discharges (PLEDs). The acronym encapsulates the essential characteristics of PLEDs, namely, wide distribution, polymorphism, one or more sharp components in a repeti-tive way (usually at the rate of one to two seconds), and localization over the hemisphere. Subsequent studies have described other variable periodic patterns as two independent PLED types in the same EEG (BIPLEDs), multifocal PLEDs, generalized periodic epileptiform dis-charges (GPEDs), and stimulus-induced rhythmic, periodic, or ictal discharges (SIRPIDs)