What it looks like
Bilaterally synchronous, symmetric discharges recurring at nearly regular intervals, with a discernible background between them. Seen in toxic-metabolic and septic encephalopathy, after cardiac arrest, and during or after status epilepticus. 1
What it means at the bedside
Frequency drives the reading. Above 2.5 Hz for 10 seconds they meet the definition of an electrographic seizure; between 1 and 2.5 Hz they sit on the ictal–interictal continuum. 1 After cardiac arrest, GPDs on a suppressed background belong to the "highly malignant" patterns. 8