The role of vigabatrin in childhood seizure disorders: results from a clinical audit.

Abstract

The emergence of visual field defects attributed to vigabatrin (VGB) treatment and intramyelinic edema in animal experiments has raised concerns about its future role in the treatment of childhood seizures. We evaluated our experience with this antiepileptic agent with retrospective analysis of database and chart audit. Of 73 patients, 43 girls and 33 boys were treated with VGB over a 7-year period. The mean age of patients at the introduction of VGB was 87 months (range, 5-257 months). In 12 of 73 cases, VGB was used as monotherapy; in 61 of 73 cases, it was used as an add-on drug. Seizure types included secondarily generalized seizures (21), mixed seizures (21), partial seizures (18), and generalized seizures (13). Seizure etiology was idiopathic/cryptogenic in 22 patients, symptomatic in 50, and undetermined in a single patient. The mean duration of therapy was 16 months (median, 10 months; range, 1-144 months). VGB was effective in 30 (seven seizure free, 23 with >90% reduction in seizures), partially effective in four (50-90% reduction in seizures), and ineffective in 38 (<50% reduction in seizures). Nearly 50% of patients with infantile spasms responded to VGB. All patients underwent ophthalmic evaluation; two (16%) of 12 patients who could undergo static threshold perimetry were demonstrated to have the characteristic visual field constriction. VGB is effective in producing a significant reduction in seizure frequency in nearly half the patients with childhood seizures, including refractory epilepsy. Despite emerging concerns regarding visual side effects, this drug retains an important role in the medical management of childhood epilepsy.