Abstracts

RATIONALE: The objective of this study is to evaluate seizure relapse rate in a short term (two years) and long term follow-up after partial or complete antiepileptic drug (AED) withdrawal in patients who were seizure free on medication for at least two years. METHODS: 99 patients with partial epilepsy with or without secondary generalization, age 14 years or older, seizure-free for at least two years, were randomized to 2 groups: tapering down and complete withdrawn of AED within six-months (46 patients), and partial dose reduction up to 50% in two months (53 patients). The patients were followed up for a long term (up to 8 years). AEDs were subsequently discontinued on patients who continued seizure-free for two years after partial (50%) drug withdrawal. RESULTS: : There was no significant difference in seizure recurrence during the first 2 years follow up between the two groups - complete drug withdrawal versus partial (50%) drug withdrawal (p>0.5): 32.6% (15/46) of patients with complete AED discontinuation and 32.07% (17/53) of patients with partial withdrawal presented recurrence of seizures during the first 2 years follow up. However, 9 of 29 (31.04%) patients who remained seizure-free after 2 years of 50% AED reduction, had recurrence of seizures when AEDs were completely withdrawn. There was no difference between the two groups on frequency of seizure recurrence on the long term follow up as well (43% and 53%). CONCLUSIONS: These preliminary data indicate that in short as well as in long term follow up there was no difference in the relapse seizure rate in the two groups. On the other hand one third of patients remaining seizure-free with 50% AED dose for 2 years presented seizures after complete AED discontinuation. This finding suggests that lower AED doses can be efficacious to protect some patients who have been seizure free on full AED dosage.