Clinical Features in Relation to Discordance of Sleep and Waking EEG in Epileptic Children

Kim, Kyu Tae; Nam, Sang Ook

Abstract

PURPOSE: Some patients showing epileptiform discharges were noted only in sleep or only in waking electroencephalogram(EEG). But children are difficult to take both sleep and waking EEG's due to poor cooperation. We carried out this study to determine the discordance between sleep and waking EEG's in epileptic children and its correlation with clinical features.
METHODS
This study included 432 epileptic children who had been admitted or visited out patient clinic of the department of pediatrics, Pusan National University Hospital from Jan. 1994 to July 2001. The medical records and EEG records of 432 epileptic children were reviewed. Both sleep and waking EEG were recorded in 142 recordings of 97 epileptic children. Retrospective analysis of medical records and EEG results were performed. The analysis included the discordance of EEG findings, age at EEG recording, age at first seizure, sex, seizure types, underlying causes, and number of EEG recordings.
RESULTS
Among 142 EEG recording cases, 46 cases showed normal recording in both sleep and waking states, 41 cases abnormal only in sleep, 8 cases abnormal only in waking, 47 cases abnormal in both sleep and waking. 49 cases(34.3%) showed discordance of sleep and waking EEG's. The discordance was correlated with age at diagnosis, especially the highest discordance rate in the age between 3 and 10 year(P<0.05). There was no significant difference in sleep and waking EEG's for age at first seizure, sex, seizure types, underlying causes, and number of EEG recordings.
CONCLUSION
Despite of the difficulty in taking both sleep and waking EEG recordings, both sleep and waking EEG's should be carried out in the patients between 3 and 10 years of age.