# GPD (Generalized periodic discharges)

From EEGpedia

- 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+:
^{[1]}**+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:

**GPD’s in a 85 years old male after a out of hospital cardiac arrest (source), the discharges are symmetric, similar morphology with the same interdischarge intervals**

**Notes**

- ↑ ACNS STANDARDIZED ICU EEG NOMENCLATURE v. 2012