PURPOSE: To investigate early predictors (6 months after diagnosis) of refractory epilepsy. STUDY DESIGN: prospective cohort study. INCLUSION CRITERIA: all consecutive children <14 years with two or more unprovoked seizures 24h apart, who were seen at our hospital between 1994 and 2004. EXCLUSION CRITERIA: patients previously examined in other centres. DEFINITIONS: refractory epilepsy: failure of >2 drugs plus >1 seizure/month for >or=18 months. ANALYSIS: risk of developing refractory epilepsy was calculated using Kaplan-Meier survival curves. Univariable and multivariable analyses of potential predictors of developing refractory epilepsy were carried out using Cox proportional hazards model. RESULTS: 343 patients were included. Mean age at diagnosis was 4.8 years (+/-3.8 SD). Mean follow-up period was 76.2 (+/-35.2 SD) months (range 24-139). Risk of developing refractory epilepsy was 8% at 6 years. Risk for idiopathic syndromes was 2%. For non-idiopathic syndromes the risk was 38% for patients with age at onset <1 year plus >1 seizure during the first 6 months after diagnosis, 9% for age at onset <1 year plus 0-1 seizures during the first 6 months, 22% for age at onset >or=1 year plus >1 seizures during the first 6 months and 3% for age at onset >or=1 year plus 0-1 seizures during the first 6 months. CONCLUSION: Risk of developing refractory epilepsy is very low in idiopathic syndromes. For the rest of patients, a simple model comprising three variables allows more accurate prediction of risk of refractoriness.
PURPOSE: To investigate early predictors (6 months after diagnosis) of refractory epilepsy. STUDY DESIGN: prospective cohort study. INCLUSION CRITERIA: all consecutive children <14 years with two or more unprovoked seizures 24h apart, who were seen at our hospital between 1994 and 2004. EXCLUSION CRITERIA: patients previously examined in other centres. DEFINITIONS: refractory epilepsy: failure of >2 drugs plus >1 seizure/month for >or=18 months. ANALYSIS: risk of developing refractory epilepsy was calculated using Kaplan-Meier survival curves. Univariable and multivariable analyses of potential predictors of developing refractory epilepsy were carried out using Cox proportional hazards model. RESULTS: 343 patients were included. Mean age at diagnosis was 4.8 years (+/-3.8 SD). Mean follow-up period was 76.2 (+/-35.2 SD) months (range 24-139). Risk of developing refractory epilepsy was 8% at 6 years. Risk for idiopathic syndromes was 2%. For non-idiopathic syndromes the risk was 38% for patients with age at onset <1 year plus >1 seizure during the first 6 months after diagnosis, 9% for age at onset <1 year plus 0-1 seizures during the first 6 months, 22% for age at onset >or=1 year plus >1 seizures during the first 6 months and 3% for age at onset >or=1 year plus 0-1 seizures during the first 6 months. CONCLUSION: Risk of developing refractory epilepsy is very low in idiopathic syndromes. For the rest of patients, a simple model comprising three variables allows more accurate prediction of risk of refractoriness.