Abstracts

Rationale: With its proven efficacy for the treatment of infantile spasms and partial-onset seizures in adults, vigabatrin has continued to gain widespread acceptance despite concerns of potential visual field impairment associated with its use. The purpose of the current study was to assess the effectiveness of seizure control achieved with vigabatrin for pediatric patients with refractory epilepsy after 6 months of therapy. Methods: We conducted a retrospective chart review of patients followed in the child neurology clinics at Cincinnati Children s Hospital between 1998-2010 who were treated with vigabatrin. Data collected included age; sex; seizure etiology, frequency, and description; and vigabatrin dosing regimen. Seizure frequency was categorized through a 0-4 scale, from seizure-free status greater than 1 month (0) to seizure-free status less than 1 day (4). Only patients under the age of 21 who were verified to have been treated for ?6 months, and whose baseline and follow-up seizure frequencies had been recorded, were included in the analysis. Results: Of 146 patients treated with vigabatrin during the analysis period, 87 were able to be included in the present analysis. Patients ages ranged from 0-20 years (mean age was 4.3 years). Tuberous sclerosis complex (TSC) was the most likely underlying etiology for seizures (84%). Most patients had daily seizures (often several per day) at baseline and had been treated with other anticonvulsants previous to vigabatrin. Partial-onset seizure (simple partial, complex partial, complex partial with secondary generalization), either alone (49%) or in combination with infantile spasms (40%), was the most common seizure type being treated. With an average daily dosage of 78 mg/kd/day at 6 months, seizure frequency on the 0-4 scale decreased from 3.8 0.5 at baseline to 2.0 1.7 at 6 months (p<0.001). Moreover, 69% of patients demonstrated improvements, and 29% went from experiencing seizures daily to being seizure-free at 6 months. Vigabatrin was effective for both TSC (p<0.001) and non-TSC (p=0.015) patients with partial-onset seizures. Vigabatrin was also effective for patients greater than the age of 2, when infantile spasms were much less likely to have been encountered in conjunction with simple partial and complex partial seizures (p<0.001). As of June 2010, 43 had remained on vigabatrin therapy, 20 were able to discontinue medication after resolution or improvement of seizures, and the remaining 24 discontinued vigabatrin because of lack of sustained efficacy, adverse events, parental concerns, or other reasons. None discontinued because of documented ophthalmologic impairment or evidence of retinal toxicity. Conclusions: Vigabatrin appears to be safe and effective for the treatment of partial-onset epilepsy for pediatric patients with or without tuberous sclerosis complex.