GPD (Generalized periodic discharges)
- Any pattern of generalized synchronous, repetitive discharges of similar morphology
- Relative symmetric
- Periodic, so with interdischarge interval recurring at nearly regular intervals.
- A pattern can qualify as periodic as long as it continues for at least 6 cycles
- Frontal- or occipital-dominant.
- If a more ictal appearance it can be categorized as GPD+:
- +F: superimposed fast activity.
- +R: superimposed rhythmic or quasi-rhythmic activity.
- +FR: superimposed fast activity and rhythmic or quasi-rhythmic activity.
- Not to be confused with intermittent rhythmic delta activity (IRDA)
- Not to be confused with lateralized of bilateral independent periodic discharges:
- ACNS STANDARDIZED ICU EEG NOMENCLATURE v. 2012