P11 – 2238: Long-term outcome in pyridoxine-responsive infantile epilepsy

Abstract

Objective To assess long-term outcome of infantile epilepsy responsive to pyridoxine (vitamin B6). Methods We inquired all pediatric neurologists treating pediatric epilepsy in Finland if they had seen pyridoxine responsive patients with infantile epilepsy. Five children with infantile spasms and hypsarrhythmia and one with focal epilepsy were reported as pyridoxine responders. Data on clinical presentation was collected from patient charts. Results All B6 responders had unknown etiology. Ages at seizure onset ranged from 4 to 7 months. The patients had been treated with p.o. pyridoxine 150 mg/day or i.v. 50 mg pyridoxal phosphate and responded within 1 to 14 days (mean 6 days). Two patients were treated with concomitant antiepileptic drugs. Duration of pyridoxine therapy varied from 6 weeks to 4 years (mean 26 months). Four patients had later seizure relapses: one at 15 months with motor seizures (stopped By valproate), another two in adolencence with focal epilepsy and one at 20 years with unclassified epilepsy. Intelligence was normal in five patients and one had a mild mental deficiency. Follow-up ranged from 8.5 to 24 years. Conclusion This study showed that long-term cognitive outcome is good for the rare patients with infantile epilepsy who respond to B6 therapy but later seizure recurrence occur. So far it is unknown, if the response is determined by genetic traits or disease-related factors.