Abstracts

Rationale: Vigabatrin(VGB) have proven efficacy in the treatment of infantile spasms, but have risk of irreversible visual field constriction. Incidence of the VGB-induced visual field constriction seems to depend on the extent of VGB exposure. To evaluate whether the therapeutic effect is maintained in infantile spasms patients receiving short course of VGB.Methods: We retrospectively reviewed patients diagnosed Infantile spasms in Seoul National University Children s Hospital between January 1997 and May 2012 who were responsive to VGB.Results: Fifty-four children were included, 19 among them received short course of VGB and changed to other drugs (13 zonisamide, 1 topiramate, 5 levetiracetam) within 6 months of VGB initiation, and 35 continued their VGB treatment. There were no statistically significant differences between VGB switch and maintenance group in the age of onset, gender, the presence of concomitant seizures, the time from spasm onset to VGB treatment initiation, the time from VGB treatment initiation to spasms remission and the VGB dose at spasm remission, but VGB maintenance group had a higher incidence of symptomatic etiology (37% vs. 66%. p-value 0.041). Cases of seizure recurrence at 12 months from spasms remission were one (other seizure) at VGB switch group and 10 (6 (17%) spasm and 4 (11%) other seizure) at VGB maintenance group. The relapse rate did not show significant statistical difference (spasm; p-value 0.080, other seizure; p-value 0.646).Conclusions: There was no increase in spasms or other seizure recurrences rate in VGB early switch group compared to VGB maintenance group. We suggest switching to other drug after the short-term VGB treatment, in order to avoid the irreversible side effects such as visual field defects. Whether this strategy can actually result in lower incidence of visual field defect should be further investigated.