Risk factors for recurrence after drug withdrawal in childhood epilepsy.

Background: Several studies have been conducted to determine the risk of recurrence after withdrawal of antiepileptic drugs (AEDs) in recent years. There is no consensus concerning the circumstances affecting discontinuation of AEDs. This study was designed to determine the recurrence rate of epilepsy after withdrawal of AEDs and the risk factors related with recurrence.

Methods: Children with epilepsy onset between 1 month and 16 years of age who were followed up at least 3 years after AED treatment withdrawal were enrolled. Patients were classified into groups according to defined risk factors for recurrence.

Results: A total of 284 patients, 137 (48.2%) girls and 147 (51.8%) boys were included, and seizures recurred after withdrawal in 51 patients (18%). Thirty-three (64.7%) patients had recurrence in the first year after withdrawal. The recurrence risk was calculated based on the electro-clinical syndromes classification; the recurrence risk was the highest in the juvenile myoclonic/absence group and lowest in the benign infantile seizure group. No recurrence was observed in the infantile spasm group. Data evaluated by multivariable analysis showed that having the structural-metabolic and unknown epilepsy and <3 years seizure free period before withdrawal of AEDs were the main risk factors for recurrence after AED withdrawal in our study.

Conclusion: We suggest a seizure-free period of at least 3 years under AED medication and we must be cautious in patients with structural-metabolic and unknown epilepsy before AED withdrawal.