Prognostic factors of drug-resistant epilepsy in childhood: An Italian study

Background: Epilepsy is drug-resistant in 30-40% of cases. We studied retrospectively the prognostic factors of drug-resistance, during fifteen years, in an Italian sample of patients with childhood epilepsy. Methods: We considered 117 patients that were divided into two groups: one with drug-resistance, and the other without drug-resistance. We compared the two groups at T0 (epilepsy onset), T2, T5, T8 and T10 (respectively, 2, 5, 8 and 10 years from the seizure onset) through Fisher’s Exact Test and Randomization Test. Then, through multiple logistic regression analysis, we searched for the most reliable predictive model of drug-resistance. Results: Positive neurological examination at onset, the presence of symptomatic/probably symptomatic etiology, lack of response to the first drug, seizure clustering during the follow-up, intelligence quotient ≤ 70, altered neuropsychological examination at onset, and cerebral lesions were predominant in drug-resistance cases. The most reliable combinations of drug-resistance predictors include partial or no response to the first drug, presence of seizure clustering during the follow-up, altered neurological examination at onset, and long latency between epilepsy onset and first drug at T2; partial or absent response to the first drug and positive magnetic resonance imaging at T5; positive magnetic resonance imaging and absence of generalized seizures at T8; and positive magnetic resonance imaging at T10. Sometimes, drug-resistance appeared after discontinuation of an effective therapy. Conclusions: Predictive factors of drug-resistance can be recognized for a good number of patients with epilepsy at disease onset, although we must acknowledge that the current possibility of predicting epilepsy outcomes remains limited.