Response to sequential treatment schedules in childhood epilepsy: risk for development of refractory epilepsy.

Purpose: To investigate response to sequential treatment schedules and risk of development of refractory epilepsy in childhood.

Methods: All children younger than 14 years with two or more unprovoked seizures seen at our hospital between 1994 and 2004 were included and prospectively followed. "Seizure control" was defined as a 2-year seizure-free interval without further recurrences except those related to attempts of medication withdrawal and "refractory epilepsy" as failure of >2 drugs plus >1 seizure/month for > or =18 months.

Results: 343 Patients were included, 191 males and 152 females. Mean age at diagnosis was 4y 10 mo (SD 3 year 10 month). Mean follow-up period was 76.2 mo (SD 35.2). The probability of achieving "seizure control" was 70% and 86% at 5 and 10 years. 59% of patients were "controlled" with the first drug used. Among patients failing the first, second and third therapeutic regimen due to lack of efficacy, 39%, 23% and 12% respectively were finally "controlled" with subsequent treatment schedules Risk of development of refractory epilepsy was 8% and 12% at 6 and 10 years.

Conclusion: After failing a first drug, a significant proportion of children can still be controlled with subsequent therapeutic schedules. Only a small proportion develops refractory epilepsy.