Vigabatrin therapy in infantile spasms.

RATIONALE: To determine the clinical outcome and side effects of vigabatrin (VGB) in the treatment of infantile spasms (IS) and its long-term outcome. METHOD: All children with IS treated with vigabatrin were studied. Clinical data regarding age of onset, duration of IS before therapy started, recurrence of IS, types of seizures that relapse, clinical outcome and side effects were monitored. RESULTS: 36 children (17 girls, 19 boys) with IS participated in the study. The mean age of onset of IS was 115.55 +/- 67.3 days old (range, 15 to 300 days). Six were cryptogenic IS and 30 were symptomatic IS. The etiologies of symptomatic IS in this study were tuberous sclerosis, hypoxic ischemic encephalopathy (HIE)/periventricular leukomalacia, porencephaly, partial agenesis of corpus callosum, hemimegalencephaly, cortical dysplasia, and microcephaly. 66.67 per cent (24 of 36) of patients responded to VGB within a mean 2.95 +/- 2.25 days (range, 1 to 7 days). In those who responded to VGB, 3 patients developed recurrent IS within 69.3 +/- 46.7 days (range, 30 to 121 days). Five patients developed epilepsy with different types of seizure during long-term follow-up. The mean duration of subsequent epilepsy after cessation of IS was 16.4 months (range, 5 months to 3 years 10 months). The mean duration of follow-up was 2.74 years (range, 1.09 years to 5.76 years). 10 patients were successfully weaned off VGB after a mean IS free period of 22.5 +/- 5.5 months (range, 12 to 27 months). Transient drowsiness was seen in 4 patients. Three patients had transient abnormal sleep patterns and irritability. Visual field abnormalities were not found but difficult to assess fully in this study. CONCLUSION: VGB therapy has a high response rate for the control of IS and is well tolerated in most children. All patients who responded to VGB and were spasm free for more than one year were successfully weaned off VGB therapy. Because serious side effects such as visual field abnormalities are difficult to monitor, the authors propose that VGB could be withdrawn or switched to another AED after a spasm-free period of more than one year.

Newer antiepileptic drugs and non surgical approaches in epilepsy.

Newer antiepileptic drugs (AEDs) have helped the management of about one third of children with epilepsy who are refractory to primary AED(s). Vigabatrin and lamotrigine are being used as first line drugs for infantile spasms and Lennox Gestaut syndrome (LGS) respectively. Most of the others are, as of now, used as add-on drugs with specific indications. The ketogenic diet has been used successfully in some children with LGS. Steroids have a clear role in infantile spasms. Efficacy of immunoglobulins is mainly anecdotal. Physicians should familiarise themselves with the efficacy, pharmacokinetics and side effects of these drugs and ensure their rational use.

Vigabatrin in infantile spasms: preliminary result.

PURPOSE: To evaluate the efficacy of vigabatrin in the treatment of infantile spasms in Thai children. PATIENTS & METHOD: From March 1996 to May 1998, patients aged under 2 years presenting with infantile spasms at Ramathibodi Hospital were initiated with vigabatrin 35-50 mg/kg/day in two-divided doses. The dosage was escalated by 25 mg/kg weekly until spasms ceased or the maximum dose of 130 mg/kg was reached. RESULTS: There were 20 patients enrolled. The ages ranged from 3 to 23 months (mean 7.6 months). They were categorized as 4 cryptogenic and 16 symptomatic. Infantile spasms were completely controlled in 12 patients (60%). Six patients (30%) had at least 50 per cent reduction of seizure frequency. There were 2 patients whose seizure frequencies and severity were not altered. Only one patient whose infantile spasms partially responded to vigabatrin developed orofacial dyskinesis which disappeared after discontinuation of vigabatrin. Five patients had their vision evaluated which was unremarkable. Based on parental global evaluation, there was an increase in alertness, cheerfulness and interaction to the environment and stimulation in 8 out of 15 patients who were still taking vigabatrin and responded to treatment. CONCLUSION: Vigabatrin is effective for infantile spasms. A long-term follow-up of these patients is necessary to evaluate its efficacy and side-effects.