Antiepileptic drugs for the treatment of infants with severe myoclonic epilepsy.

BACKGROUND: This is an updated version of the original Cochrane review published in Issue 11, 2013.Severe myoclonic epilepsy in infants (SMEI), also known as Dravet syndrome, is a rare, refractory form of epilepsy, for which stiripentol (STP) has been recently licensed as add-on therapy.

OBJECTIVES: To evaluate the efficacy and tolerability of STP and other antiepileptic drug treatments (including ketogenic diet) for patients with SMEI.

SEARCH METHODS: We searched the Cochrane Epilepsy Group Specialised Register (27 April 2015), the Cochrane Central Register of Controlled Trials (CENTRAL; 27 April 2015) and MEDLINE (1946 to 27 April 2015). We systematically searched the online trials registry ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform and the bibliographies of identified studies for additional references. We handsearched selected journals and conference proceedings and imposed no language restrictions.

SELECTION CRITERIA: Randomised controlled trials (RCTs) or quasi-randomised controlled trials; double- or single-blinded or unblinded trials; and parallel-group studies. Administration of at least one antiepileptic drug therapy given singly (monotherapy) or in combination (add-on therapy) compared with add-on placebo or no add-on treatment.

DATA COLLECTION AND ANALYSIS: Review authors independently selected trials for inclusion according to predefined criteria, extracted relevant data and evaluated the methodological quality of trials. We assessed the following outcomes: 50% or greater seizure reduction, seizure freedom, adverse effects, proportion of dropouts and quality of life. We assessed outcomes by using a Mantel-Haenszel meta-analysis to calculate risk ratios (RRs) with 95% confidence intervals (95% CIs).

MAIN RESULTS: In the updated search, we identified no additional studies suitable for inclusion. We found no RCTs assessing drugs other than STP. The previous version of this review included two RCTs evaluating use of STP (total of 64 children). Both studies were generally at unclear risk of bias. A significantly higher proportion of participants had 50% or greater reduction in seizure frequency in the STP group compared with the placebo group (22/33 vs 2/31; RR 10.40, 95% CI 2.64 to 40.87). A significantly higher proportion of participants achieved seizure freedom in the STP group compared with the placebo group (12/33 vs 1/31; RR 7.93, 95% CI 1.52 to 41.21). Investigators found no significant differences in proportions of dropouts from the STP group compared with the placebo group (2/33 vs 8/31; RR 0.24, 95% CI 0.06 to 1.03). Only one study explicitly reported the occurrence of side effects, noting that higher proportions of participants in the STP group experienced side effects than in the placebo group (100% vs 25%; RR 3.73, 95% CI 1.81 to 7.67).

AUTHORS' CONCLUSIONS: Data derived from two small RCTs indicate that STP is significantly better than placebo with regards to 50% or greater reduction in seizure frequency and seizure freedom. Adverse effects occurred more frequently with STP. Additional adequately powered studies with long-term follow-up should be conducted to unequivocally establish the long-term efficacy and tolerability of STP in the treatment of patients with SMEI.