Treatment of the West syndrome with high-dose pyridoxal phosphate.

Fifteen (12.7%) among 118 cases of the West syndrome were effectively treated by high-dose pyridoxal phosphate (PAL-P). 1) Clinical seizures were completely suppressed in 12 cases with PAL-P alone, and in 3 cases by an addition of PAL-P to the previously poorly-effective regimen. At the follow-up, 12 cases have continued to be free from seizures, while two cases relapsed into the Lennox-Gastaut syndrome, and one died. 2) Electroencephalographically hypsarhythmia disappeared by PAL-P in all 15 effective cases. 3) Effective daily dose of PAL-P was 30 to 400 mg. 4) Notably, PAL-P was effective even in the cases with obvious organic brain pathology, such as tuberous sclerosis, porencephaly, holoprosencephaly, postmeningitis, besides 5 idiopathic cases. 5) Efficacy of PAL-P was significantly higher in idiopathic cases than symptomatic cases; 35.7% vs 9.6%. 6) Response to PAL-P was not predictable by any laboratory data nor clinical features. 7) Prognosis of PAL-P responsive cases was favorable; as many as 6 cases developed normally among 14 cases followed-up. Treatment with a high-dose PAL-P should be tried in all cases of the West syndrome at first.