One vs. two years of anti-epileptic therapy in children with single small enhancing CT lesions.

The duration of anti-epileptic drug (AED) therapy in children with seizures due to single small enhancing CT lesions (SSECTL) is controversial. We sought to determine whether there is any difference in the rate of seizure recurrence after 1 vs. 2 years of AED therapy and to identify the factors predictive of seizure recurrence. A total of 115 consecutive children with seizures and SSECTL were randomly assigned to two groups. Group A received AED(s) for 1 year and Group B for 2 years seizure-free interval. CT scan and EEG were done prior to AED withdrawal and children were followed-up for seizure recurrence for at least 1 year. Association between seizure recurrence and clinical and CT characteristics was analysed. Groups A and B consisted of 55 and 51 children, respectively (nine were lost to follow-up). There were 61 boys and 45 girls; mean age 9.33 years. Most (93 per cent) had focal seizures: 36 per cent complex partial, 22 per cent simple partial, 35 per cent partial with secondary generalization; 21 per cent had status epilepticus. The two groups were comparable in clinical, EEG and CT characteristics. CT scan and EEG prior to AED withdrawal were abnormal in 44 per cent and 33 per cent respectively. Six children, three from each group had seizure recurrence. Significant association was found between seizure recurrence and abnormal CT (persistence/calcification of lesion) and abnormal EEG prior to AED withdrawal (p < 0.01). The relative risk of seizure recurrence in a child with abnormal CT and EEG prior to AED withdrawal was 26.2 (95 per cent confidence interval 3.3-210.2, p = 0.0003). No association was found between seizure recurrence and any of the other variables. There was no difference in seizure recurrence after 1 vs. 2 years of AED therapy. Combination of persistent/calcified CT lesion and abnormal EEG prior to AED withdrawal was the best predictor of seizure recurrence.