How long to treat childhood onset absence epilepsy

The relation between the duration of treatment and achievement of seizure-free state after stopping medication in childhood onset absence epilepsy (COAE) has not been established, and children are usually treated for periods of 2-4 years. We hypothesized that a group of patients defined by prompt total clinical and electrographic remission, verified by 24-hour ambulatory EEG, could be withdrawn from treatment without recurrence. Three patients with new onset of COAE were treated. Ethosuximide (ESM) was used as first line drug. Dosages correlated with blood levels were gradually increased until a clinical and electrographic seizure-free state was achieved. The three responded to ESM promptly at therapeutic blood levels (75-90 mcg/ml). The effects of a 5- to 6-week period of withdrawing ESM after 6 months of treatment were as follows: a 10-year-old boy remained seizure-free with recurrence of inter-ictal 3/second spike-wave bursts; 5- and 10-year-old girls remained seizure-free and their 24-hour ambulatory EEG burst-free. Our findings suggest that optimization of treatment in COAE, aimed at achieving an electroclinical and electrographic seizure-free state, may identify patients in whom therapy can be successfully ended much sooner than has been usual. Thus the same good prognosis may be reached in a shorter period of treatment with minimal risk of recurrence of absence seizures.