Long-term follow-up of childhood epilepsy treated with vigabatrin outside of clinical trials
Experimental conditions are not mirrored by clinical practice. To study the efficacy of vigabatrin in the usual conditions of everyday clinical practice. Retrospective review of all epileptic patients treated with vigabatrin in a neuropediatric outpatient clinic. a) Persistent seizure frequency reduction > or = 50%, and total control of seizures. Potential predictors of response were studied by logistic regression. b) Duration of VGB therapy, studied by the Kaplan-Meier method and its associated log-rank test. 113 patients with: partial symptomatic epilepsy (38%), partial cryptogenic (25.6%), partial idiopathic (6%), West syndrome (14%), Lennox-Gastaut syndrome (6%), other syndromes (9.7%). Reduction of seizure frequency was attained by 60% of patients at 3 months, sustained during 12 months by 40%, and during 5 years by 14%. Total control of seizures was present in 33% of patients at 3 months, persisted 12 months in 18% and 5 years in 2%. Independent predictors of a poor outcome were generalized seizures (except infantile spasms) and cerebral palsy, among others. The probability of continuing vigabatrin (VGB) therapy was 78% at 6 months, 55% at 2 years and 32% at 5 years. Duration of therapy was modified by early therapeutic response and antecedent of status epilepticus, among others. Adverse events were recorded in 18.5%. Visual fields were not studied in these series. For the time being, VGB-treated patients belong to the difficult-to-treat group. Percentages of responders depend upon duration of follow-up.