A Study on the Clinical Significance of Periodic Lateralized Epileptiform Discharges and Relation to Brain Imaging Study in Children

Purpose : Periodic lateralized epileptiform discharges(PLEDs), initially described by Chatrian et al in 1964, are an EEG phenomenon characterized by lateralized or focal spike-and-wave complexes with moderate to high voltage which occur in a periodic or semiperiodic pattern. This study was performed to assess the clinical significance of PLEDs and its relation to an imaging study of the brain. Methods : Twenty children(10 males and 10 females), from 2 days to 14 years of age, who had been hospitalized at Hanyang University Hospital were studied retrospectively. Their medical records, EEG results and brain imaging study were reviewed. Results : Of the 20 patients studied, 15 patients showed unilateral PLEDs and 5 had bilateral PLEDs in EEG. Brain imaging studies were done for 18 of the patients, revealing abnormalities in 15 patients in this order of frequency : intracranial hemorrhage, diffuse cerebral atrophy, leukomalacia, cerebral infarctions, cerebral edema and hydrocephalus. PLED sites were not significantly correlated with the results of the imaging study. Finally, 3 patients died and 17 patients survived, and among the surviving 17 patients, 5 had recurrent seizures, 1 had recurrent seizures with mental regression, 3 had neurologic sequelae without seizures and 8 had no neurologic sequelae. Conclusion : We conclude that children who show PLEDs in EEG are more commonly associated with acute cerebral lesions and there is a high incidence of subsequent seizures and/or other neurological sequelae in surviving children with PLEDs. (J Korean Pediatr Soc 1999;43:380-385)