Vigabatrin and mental retardation in tuberous sclerosis: infantile spasms versus focal seizures

Abstract

Tuberous sclerosis complex is a genetic disorder resulting in epilepsy and mental retardation. Vigabatrin has shown efficacy in the treatment of infantile spasms caused by tuberous sclerosis complex, but its effects on focal seizures caused by tuberous sclerosis complex have not been determined. We compared the efficacy of vigabatrin in patients with tuberous sclerosis complex-induced focal seizures and infantile spasms and assessed the mental outcomes in both groups. We retrospectively evaluated 31 children with tuberous sclerosis complex and epilepsy, who were treated with vigabatrin in a single tertiary center in Seoul, Korea. Vigabatrin treatment resulted in spasms cessation in 16 of 18 (88.9%) patients with infantile spasms, whereas 6 of 13 (46.2%) patients with focal seizures became seizure free. Initial response to vigabatrin had no effect on intellectual disability. Vigabatrin was highly effective in eliminating infantile spasms caused by tuberous sclerosis complex but was less effective in patients with focal seizures.

Figure 1

Study design. Of the 39 patients with tuberous sclerosis complex and epilepsy, 31 patients had been treated with vigabatrin as first- or second-line therapy within 1 month of seizure onset. Patients were divided into those with infantile spasms and focal seizures at initiation of vigabatrin, except for one patient with concurrent infantile spasms and focal seizures, who was regarded as having infantile spasms. Thus, 18 patients had infantile spasms (underlined) and 13 had focal seizures (italics). Of the 17 patients who initially presented with infantile spasms, 9 evolved to other types of epilepsy, whereas, of the 13 patients who initially presented with focal seizures, only one evolved to infantile spasms. Abbreviations: TSC, tuberous sclerosis complex; VGB, vigabatrin; IS, infantile spasms; focal seizures, focal seizures; LGS, Lennox-Gastaut syndrome; ACTH, adrenocorticotropic hormone; VPA, valproic acid