Bilateral independent periodic lateralized epileptiform discharges. Clinical significance.

Clinical data on 18 patients whose EEGs showed bilateral independent periodic lateralized epileptiform discharges (BIPLEDs) were reviewed and compared with those of 45 patients with periodic lateralized epileptiform discharges (PLEDs). A recent stroke was the most frequent cause of PLEDs (33%), while anoxic encephalopathy (28%) and CNS infection (28%) accounted for the majority of BIPLEDs. Focal neurologic deficits, focal seizures, and focal computed tomographic scan abnormalities were frequent in those with PLEDs, while coma predominated in the group with BIPLEDs (72% vs 24%). Mortality was also higher in patients with BIPLEDs--61% vs 29%.