Risk factors of relapses in epileptic patients after antiepileptic drug reduction or withdrawal

Background: Antiepileptic drugs can be successfully withdrawn in up to 70% of cases. The timing of withdrawing antiepileptic drugs in children is 1-2 years, in adults 2-5 years after of seizure free period. The relapse rate is 1/3 at least 2 years. The risk factors of relapsing were brain scanning findings, positive pathological EEG activities, partial epileptic attacks. On the other hand, early-onset epilepsy and idiopathic epilepsy have a better prognosis for relapsing and lower risk of seizure recurrence. In our study, we investigated the relation between patient and disease characteristics in patients with relapse developing and the duration of remission/relapse. Secondly, factors of relapse rate, remission duration and medication after relapse were investigated. Material-Method: In our study, 6000 epilepsy patients were observed retrospectively. 244 patients who had relapse after drug reduction or withdrawal at least one year were included. Results: Follow-up of at least 1 year and relapsed patients in our clinic who were followed regularly was required for inclusion in this study. Some cases who loss to follow-up after drug reduction or withdrawal were excluded from study. Therefore, the definite relapse ratio can not be evaluated. If we accept the 510 follow-up patients who loss to follow-up had no relapse, the relapse ratio could be %41. %53 of patients after withdrawn was observed relapse at least one year. The patients with using polytherapy go into remission much later and are detected relapse much earlier. This may be associated with early-wrong monotheraphy and unnecessary polytheraphy. There is a significant negative correlation between the duration of remission and the duration of relapsing. As duration of remission gets longer, duration of relapsing gets earlier. There is no significant relationship between age at seizure onset, gender, disease duration, EEG findings, family history and duration of remission/relapse. The number of seizure type and duration of relapse and withdrawal drug is significantly correlated with each other. The patients with nocturnal seizures or automaticity or aura is seen longer remission and earlier relapse. But these findings are not statistically significant. Conclusion: During the withdrawn of drug, variety of seizure and duration of remission should be evaluated. The history of patient is primarily taken into consideration for planning the treatment.