Sleep duration and behavior were assessed in 46 children (age range 1.7-17.4 years) before and after tapering valproic acid (VPA) administered for more than 6 months for epilepsy, in a study at University Children's Hospital, Zurich, Switzerland. Actigraphy data obtained for 7 consecutive days and nights showed that after termination of VPA 33 children slept less (>30 min in 9 patients) and 13 children slept longer (>30 min in 1). Mean Actual Sleep Time per Day was significantly reduced after VPA termination (-10.7 min) in children older than age 6 years. Gender and dose of VPA were not contributing factors. Questionnaire data showed no significant difference in bed and wake time, duration of sleep, and time to fall asleep before and after ending VPA treatment. 
COMMENT. Termination of VPA after long-term treatment for epilepsy is associated with a small but significant reduction of sleep duration, but only in children older than 6 years of age. The reason given for initiating this study was frequent parental reports that sleep duration increases during VPA treatment and decreases when medication is suspended. The results partly confirm the parental observations.