Short Course and Early Switch of Vigabatrin for Infantile Spasms

Abstract

Purpose Vigabatrin has proven efficacy in the treatment of infantile spasms, but carries the risk of irreversible visual field constriction. Incidence of the vigabatrin -induced visual field constriction seems to depend on the extent of vigabatrin exposure. The aim of this study was to evaluate whether the therapeutic effect is maintained in patients with infantile spasms receiving a short vigabatrin course followed by switching to another antiepileptic drug (AED). Methods Patients with infantile spasms responsive to initial vigabatrin treatment were divided into two groups: a vigabatrin switch group (n=25) and a vigabatrin maintenance group (n=41). Vigabatrin was switched to other drugs within 6 months of spasm remission. The rate of seizure recurrence at 6 and 12 months from spasms remission was compared between the two groups. Results There were no statistically significant differences between the vigabatrin switch and maintenance groups in the age of onset, presence of concomitant seizures, time from spasm onset to vigabatrin treatment, time from vigabatrin treatment initiation to spasm remission and vigabatrin dose at spasm remission. The number of patients with seizure recurrence at 12 months from spasm remission was 3 (3/25, 12%) in the vigabatrin switch group and 10 (10/41, 24.4%) in the vigabatrin maintenance group. The seizure recurrence rate at 12 months from spasm remission was not significantly different between groups. Ten of 13 patients with seizure recurrence had symptomatic etiology. Conclusion A short course of vigabatrin could be considered in patients with infantile spasms who were responsive to initial vigabatrin treatment, since spasm remission was maintained after switching to other drugs. Whether this strategy could ultimately result in lower incidence of visual field defect should be further investigated.