Brief potentially ictal rhythmic discharges and paroxysmal fast activity as scalp electroencephalographic biomarkers of seizure activity and seizure onset zone.

A high proportion of patients with BIRDs/PFA had seizures on EEG, regardless of their frequency (i.e., whether they also qualified as PFA), and their location colocalized with scalp SOZ in all cases. BIRDs appear to be a scalp EEG biomarker of uncontrolled seizure activity and a reliable localizing sign of the SOZ.