Abstracts

Although the rate of seizure recurrence following planned discontinuation of antiepileptic drugs (AEDs) in seizure-free patients is well known, less information is available if reinstitution of treatment invariably results in prompt and complete seizure control. A literature review was performed yielding 12 retrospective observational studies of AED discontinuation with data on seizure outcome after resumed therapy. Reinstitution of AEDs after recurrence did not result in complete seizure control during the last year of follow-up in 21% of patients (mean of 12 studies, 95%CI:15-26) after an average of 3 years of resumed treatment. In 7-9% of cases, chronic drug-resistent epilepsy was noted with many seizures over as many as 5 years. Although seizure control was regained in approximately 50% of those becoming seizure-free within one year, it took as many as 5-12 years for some patients to regain seizure-freedom after a recurrence. Factors associated with poor treatment response after recurrence were symptomatic etiology, partial epilepsy and cognitive deficits. Although it is reassuring that AED reinstitution after a seizure recurrence following planned discontinuation in seizure-free patients is successful in approximately 90% of patients, complete response may be delayed as late as 12 years after restarting treatment in some cases. Unexpectedly, epilepsy may prove to be severe and uncontrollable in 7-9%. These risks must be mentioned when discussing AED discontinuation with seizure-free patients.