Pyridoxal phosphate-responsive epilepsy with resistance to pyridoxine.

We present a female infant with seizures responsive to pyridoxal phosphate but that are resistant to pyridoxine. The mechanism by which pyridoxal phosphate controls seizures in this patient is unknown. Her seizures are perhaps not solely caused by pyridoxal phosphate deficiency. It is suggested that in addition to glutamic acid decarboxylase abnormality, the path from the absorption, transportation, phosphorylation, and oxidation of pyridoxine to pyridoxal phosphate in this patient might be defective. It should be considered whether pyridoxal phosphate can be the drug of choice instead of pyridoxine in treating patients suspected of pyridoxine-dependent epilepsy to reduce failure rate and further delay in seizure control.