ORIGINAL ARTICLES

PYRIDOXINE (VITAMIN B₆) IN EPILEPSY: A CLINICAL TRIAL

Vitamin B₆ (VB₆)-related seizures include clinical seizures associated with VB₆ deficiency and dependency. Both types of seizures are suppressed by VB₆. We proposed VB₆-responsive seizures as the third category of VB₆-related seizures in 1977. Vitamin B₆-responsive seizures decrease or disappear in response to high-dose oral VB₆. Seizure onset in most of our cases occurred within the first year of life, although this varied between 3 months and 5 years. Etiologically, such cases were not only idiopathic or cryptogenic, but also symptomatic and associated with organic brain lesions. The tryptophan load test was usually negative. Vitamin VB₆-responsive seizures or epilepsy were usually West syndrome (WS), however may also include Lennox-Gastaut syndrome, grand mal or partial motor seizures. High-dose VB₆ treatment administered to 216 consecutive WS cases had an overall response rate of 13.9%, being high not only in cryptogenic cases (32%), but also in symptomatic WS (11.5%) associated with identifiable brain pathologies. Notably, responsive patients had excellent long-term seizure and mental outcomes without the need for conventional antiepileptic medication. A gradual increase in clinical response to VB₆ was noted with increasing the VB₆ dose from 30 to 50–100 mg/day, and a dramatic increase in clinical response with high-dose VB₆ (100–400 mg). Little clinical response was noted with administration of low dose VB₆ (10–30 mg/day). Thus, high-dose oral VB₆ treatment is recommended in all WS patients at time of initial treatment for a minimum of 10 days, considering the safety and rapid onset of efficacy, usually within 1 week, of this treatment.

Approximately 10–30% of patients with West syndrome respond to high-dose vitamin B₆ treatment. The response to vitamin B₆ is rapid; seizures disappear within the first 2 weeks of treatment. Mild side effects, such as gastrointestinal symptoms and liver dysfunction, are observed in 40–70%, but these resolve after discontinuation or a reduction of the dosage of vitamin B₆. High-dose vitamin B₆ treatment is useful as a first line agent in treating West syndrome.