Factors associated with seizure recurrence after antiepileptic drug withdrawal

Özet

In seizure-free patients, there are difficulties in deciding to discontinue treatment and optimal timing of withdrawal. We aimed to investigate the disease characteristics associated with recurrence of seizures after discontinuation of antiepileptic drugs (AEDs), as well as the factors affecting the time to seizure recurrence. Patients with epilepsy who had seizure recurrence after withdrawing AED treatment for at least 2 years of the seizure-free period included. The demographic and clinical characteristics of the patients were recorded. Of the 107 patients included, time to recurrence of seizures after AED withdrawal was 18 (1-188) months. Univariate cox regression analysis showed that later onset of epilepsy, older age at AED withdrawal, discontinuation of treatment by the patient, and shorter AED withdrawal periods were associated with recurrence (p=0.041, p=0.028, p<0.001, and p=0.001, respectively). In the multivariate analysis, discontinuation of therapy by the patient (HR 0.491; 95% CI 0.266-0.906; p=0.023) and shorter AED withdrawal periods (HR 0.938; 95% CI 0.888-0.991; p=0.022) were independently associated with recurrence. Earlier seizure recurrence was associated with later onset of epilepsy, fewer seizures in the first 6 months, higher age at AED withdrawal, discontinuation of treatment by the patient, shorter AED withdrawal period, and monotherapy in univariate linear regression analysis (p=0.021, p=0.032, p=0.012, p=0.008, p=0.001, and p=0.042, respectively). In multivariate analysis, the AED withdrawal period was found to be associated with early recurrence (SE 0.968; 95% CI for B 0.721-4.561; p=0.008). Our results indicate that a shorter AED withdrawal period is the most important factor related to increased and earlier seizure recurrence. Older age either at the onset of disease or at the withdrawal of AEDs seems to be related to the risk of earlier recurrence.