Abstracts

Rationale: Tuberous sclerosis complex (TSC) is a genetic disorder that characterized by hamartomatous growth throughout the body causing high rates of epilepsy, and mental retardation. Vigabatrin (VGB) is a structural analogue of ?-aminobutyric acid (GABA) that irreversibly inhibits GABA-transaminase under assessment for treatment of infantile spasm and refractory complex partial seizure. The objective of this study is to assess the efficacy of VGB specifically for partial epilepsy and infant spasms caused by TSC. Methods: Thirty-nine children (M:23, F:16) were included in this study, all of whom had been diagnosed with TSC and epilepsy between 1991 and 2010. Data were retrospectively reviewed for seizure types and the usage of AEDs. In order to avoid the selection bias and to exclude the impact of drug interaction, we reviewed the patients treated with VGB as the first monotherapy or second add-on therapy. The efficacy for VGB was defined as seizure freedom for 8 weeks after initiation for partial seizures and 4 weeks for infantile spasms. Results: Eleven from 17 patients with partial epilepsy and 20 from 22 patients with infantile spasms used the VGB. For the initial monotherapy, 2 of 6 (33%) patients with partial epilepsy became seizure free and 12 of 15 (80%) patients with infantile spasms became seizure free. Overall seizure free rate of VGB was 45% (5/11) of patients with partial epilepsy caused by TSC and 80% (16/20) of patients with infantile spasms caused by TSC, which was significantly higher than that in patients with partial epilepsy (p<0.05). Of the 16 infantile spasms patients with seizure freedom achieved by VGB, 12 patients experienced recurrence of seizure later, and became refractory to medical treatments. Only four patients remained seizure-free, three of them switched from VGB to zonisamide because of risk of long term side effect of VGB. Conclusions: VGB showed a high efficacy in eliminating infantile spasms with patients with TSC, but not in those with partial epilepsy. Considering the efficacy and the long-term side effect of visual field defect, VGB can be used as first choice for the infantile spasms not for the partial epilepsy in patients with TSC.