Does Early Recognition of Treatment Failure and Changing Anti-Epilepsy Medication Regimen Improve Short-Term Seizure Remission Rates In Childhood Absence Epilepsy?

PURPOSE: To study the role of early serial EEGs in improving seizure freedom rates after initiation of ethosuximide or valproic acid for childhood absence epilepsy.

METHODS

Retrospective data analysis study of AED naive patients with childhood absence epilepsy undergoing treatment at the community-based epilepsy clinic. Due to small sample size Fisher's exact test was used to determine two-tailed p value at less than 0.05 statistical significance..

RESULTS

At 2-month study period 71.4% patients in the ethosuximide and 87.5% in the valproic acid group achieved seizure freedom, with EEG normalization in 21.4% and 50% respectively. At 6-month study period, in patients continuing ethosuximide, seizure freedom and EEG normalization rates were 89.5% and 52.6% respectively; while in patients continuing valproic acid, results were 100% and 78.6% respectively. Both at 2-month and 6-month study periods, a trend towards higher seizure freedom was noted in patients with typical versus non-typical epileptiform discharges at baseline with the valproic acid group showing a superior response.

CONCLUSION

Although no statistically significant difference in response rates was noted, 1) a shift towards higher seizure freedom with valproic acid; 2) improved response after switching to valproic acid at 2 months, if warranted; and 3) superior response rate in patients with typical EEG epileptiform discharges at baseline were observed. A larger study is needed to define the role of early serial EEGs to delineate higher drug failure probability; and to determine the importance of non-typical EEG characteristics at baseline in relation to the choice of AED and long-term outcome Keywords: childhood absence epilepsy, ethosuximide, valproic acid, non-typical epileptiform discharges.