Prognosis after therapy discontinuation in children with epilepsy

Anticonvulsant therapy was stopped in 191 epileptic children (109 males and 82 females) after a seizure-free period of at least 2 years, independent of EEG findings, followed up for a minimum of 2 years after withdrawal. Overall, 43 (22.5%) had recurrence of seizures; of these, 79% relapsed within the 1st year after drug stopping and 93% within the 2nd year. The probability of remaining seizure free was 97% at the end of the withdrawal period, 82% 1 year later, 79% at 2 years and 77% at 5 years. In order to evaluate the risk of recurrence and the predictive factors of relapse, several parameters were investigated by univariate and multivariate statistical analysis. At univariate analysis, the factors which proved to be significantly correlated to relapses were: age at onset over 4 years, seizure-free time less than 2 years, sudden drug discontinuation, pathological EEG records during seizure-free time and paroxysmal responses to intermittent photic stimulation (IPS). At multivariate analysis, only age at onset, seizure-free time and sudden discontinuation were the factors indicating a significantly higher relapse risk; paroxysmal IPS responses, when analyzed in association with these variables, proved to be significant and increased the predictive value for prognosis of associated factors.